Tài liệu PART- II SHEEP AND GOAT PRODUCTION doc

On open range there may be overuse with more females per ram/buck, fighting with other males and little or no supplemental feed, rams/bucks get run down lose condition during the breedin

SHEEP AND GOAT PRODUCTION

Bakht Baidar Khan

Arshad Iqbal Muhammad Iqbal Mustafa

Department of Livestock Management

University of Agriculture Faisalabad

2003

The past more than half a century is a witness to the fact that except a few, no serious attempts have been made to write books even on a few of the so many wide open aspects of the field of animal sciences Among other factors that keep the animal science sector lagging behind, utter lack of relevant books of local origin is probably the most important The dearth of documented information concerning various species of our farm animals adversely affects the learning potential of our students, who have been reported to complain about the non-availability of professional books written in Pakistan I personally feel that as animal scientists we cannot exonerate ourselves of this responsibility Of course, not all of us would have the aptitude to write books However, those who opt to take up this tiresome and time-consuming job, their efforts must be appreciated We must not forget that beginnings are always small

It is really encouraging to learn that sheep and goats being the victims of a long neglect, have attracted the attention of experienced animal scientists and teachers of long standing to write a book on them A look into the contents of the book ‘Sheep and Goat Production’, makes me believe that it would adequately serve the purpose for which it has been produced Its made-easy format would be rather more helpful to the students, field workers and progressive farmers A collection of over 650 questions along with their answers should more than suffice to cover the discussion on important topics in relation to sheep and goat production

Sajjad Zaheer Malik

Director General (Ext.)

L & DD Dept., Punjab

PREFACE

Innumerable publications on sheep and goat farming/production are there in the world market More than 98% of them are of foreign origin and are thus either not available here or their prices are beyond the means of a common man The book under discussion has not been produced to burden the market with another such publication rather it has been brought out employing a novice format to meet the requirements of beginners who venture to plan a small ruminant enterprise, but are found confronted with a series of questions Answers to many of such questions are already embodied in this ‘easy to read and understand’ book In addition, feasibilities in respect of keeping sheep and goats (pertaining to one breed of each spp.) have been outlined herein to facilitate the solution of their input: output dilemma

Another section of society most pertinent to books is professional students community It often happens that even at the end of an academic session/semester, many students in a class, would not know what type of questions, relevant to a course, may be asked in the Exam This book, for sure, would create an awareness in them as to the type of Exam questions and as to the manner of answering them Among other features of the book are: the discussion on behaviour and welfare of small ruminants and clues on the application

of biotechnology in animals A comprehensive review on terminology related to various aspects of small ruminants is also a part of this book Most of the answers to the questions included in this book have been picked up as such from various sources of literature listed under references at the end We feel highly obliged in sharing the fruit of hardwork of those so many authors/editors Under the circumstances it does not seem possible for us to individually convey to them our grateful thanks, but indeed we remain indebted to all

of them

No book will ever be complete and this one is no exception since knowledge about sheep and goats is increasing so rapidly that no book can be an absolute ultimate We feel no hesitation to mention here that at places details of a few most sophisticated techniques used abroad in small ruminant production have been intentionally avoided simply because farmers/producers here have yet to go a long way to enable themselves to take full advantage of such costly tools and techniques

We would like to record our thanks to our colleagues, namely Drs Muhammad Younas, Muhammad Abdullah, Muhammad Yaqoob, Syed Hassan Raza and Prof William Hohenboken, a friend from USA; all of them provided us a lot of useful literature for this book Special thanks are extended to Mr Farooq Ahmed, Dr Akhter Saeed and Dr Asad Saeed for arranging recent literature for the purpose from abroad

Suggestions in black and white from any quarter to effect further improvement and to remove any omissions in the contents of this book will always be welcome

Arshad Iqbal Muhammad Iqbal Mustafa

PART- II includes following contents of the book:

• BREEDING AND REPRODUCTIVE MANAGEMENT

• PROBLEMS OF PREGNANT EWES/DOES

BREEDING AND REPRODUCTIVE

MANAGEMENT

Most people who farm sheep/goats or for that matter any farm animal, would expect to gradually improve the productivity of their stock Big improvements can often be made

by changes in husbandry practices so that the animals become fitter, healthier and better fed However, there will be limitations on how much productivity can be increased in this way These limitations will be the result of the genetic make-up of the animals In other words all animals are born with a potential for production and that potential is the result

of mixing of characteristics inherited from the animals’ parents, grandparents and, in fact, all of its ancestors By selecting animals with certain characteristics and mating them it is possible to gradually improve the performance of that line, generation by generation Some characteristics are readily passed on and are highly heritable while others are not readily passed on and are referred to as of low heritability

Since it is not possible to discuss genetic gain or improvement without a basic understanding of genetics, therefore, for the purposes of this book only a simplified explanation is given All inherited characteristics are carried by genes, which occur in pairs, one from the sire and one from the dam A pair or more of genes will control a particular characteristic and thus in the case of colour a goat will either be coloured or white (most of the discussion made here in respect of goat, just as an example, is equally applicable to sheep) If the goat has a gene for colour from one parent and one for white from the other, it will, in fact, be white because white is what is called a dominant gene and colour is what is called a recessive gene If two different genes for a particular colour come together, the dominant gene will always be expressed If in this example the goat had received genes for colour from both its parents, it would then have been coloured If

an animal is carrying a pair of identical genes for a particular character such as the coloured offspring in the example, it is known as homozygous for that particular character If it carries different genes like the goat in our example with the genes for white and colour, it is termed heterozygous

The appearance of an animal as controlled by its genetic make-up is referred to as its phenotype In this example, the white goat is phenotypically white but its genotype is white/coloured This is shown in Figure 6 where two goats are mated One is homozygous for white and will be genotypically white The other is heterozygous and will be phenotypically white because white is dominant When these two are mated, their kids or what is called F1 generation, could be like the parents either heterozygous or homozygous white If, however, both parents were heterozygous white, the offspring would be either white or coloured in the ratio 3:1 (Figure 7) with 1 homozygous and phenotypically white, whereas the other 2 whites would be heterozygous and 1 would be homozygous for colour and would therefore be (phenotypically) coloured It is rare for a single gene to control a characteristic or trait as shown in the simple example but it serves

to show how characters are inherited

With selective breeding the intention is to cross animals together in such a way that the progeny will hopefully be even better than their parents It helps if the genetic make-up of the parents is known Some characteristics are linked to others and it may be, in selecting

for one desirable feature or trait, that one also selects for an undesirable feature, which may cancel out or be even less desirable than the trait that was being selected for One such trait in goats is polledness or hornlessness If a naturally polled male is mated with a female carrying the gene for polledness, there is a good chance of producing female offspring that will be homozygous (pure) polled animals These will be inter-sexed, which means they may have some parts of the male and female reproductive tract and characteristics and they will be infertile They are not, as some people describe, hermaphrodites, which means possessing both female and male sexual organs Naturally polled males do occur without the problem of inter-sex but evidence suggests that fertility

is lower in these

If traits or characteristics are of low heritability, the genetic gain achieved by selecting specific animals showing those characteristics will be less than for traits of high heritability Thus the hope for improvement will be achieved only slowly over a number

of generations

There is an old saying “breed the best to the best and cull the rest” It sounds no less than

a universal truth Your chances of improving your flock are practically nil if you breed your ewes/does to the neighbour’s nondescript ram/buck simply because it happens to be cheap and available You are not going to milk the buck, but never forget that you are going to get milk from its daughters and meat from its male offspring If the sire is not better than the ewe/doe, you are not working for breed improvement In fact, you are not even breeding sheep/goats, you are merely freshening them To further elaborate, a reference to commercial dairy farming in several western countries appears logical

Almost invariably these practical, tough-minded, cost-conscious farmers use the best

purebred registered animals they can find Milk production per cow has more than doubled during the last century While some of that, of course, is due to better feeding practices, surely a large share of the credit must go to genetics No animal is perfect, all have faults It is the job of the breeder to eliminate those faults as much as possible in future generations, while at the same time preventing new ones from showing up

Although multiple births certainly require more attention and care, yet the profits seem worth the effort In USA, at one of the universities the data were analysed in this respect and it was stated that it would require 5721 ewes producing one lamb each to yield a

$25000 profit, while 353 ewes producing two lambs each to equal it These figures seemingly sound strange, but consider the vast reduction in the amount of grain and hay expenses (grain feeding not largely practised under our conditions) for the smaller number of ewes, to produce double the number of lambs The same is applicable to goats Choose your potential replacement ewes/does from among your earlier-born twin ewes/does Turn these twin ewe lambs/doe kids in with a ram/buck wearing a marking harness The ones that are marked and presumably bred, can be kept for your own flock and sell the rest Ewe lambs/doe kids that have twins the first time are more valuable than those who lamb/kid with a single, even though ewes/does with a future history of twinning may have only a single that first time Still they pass on both the inherited ability to breed early and to have twins and they will produce more lambs/kids during their lifetime However, it all depends on how well fed the animals are

Some mating occurs throughout the year but the principal breeding seasons remain

autumn and spring Hand mating is not known since it may be impracticable in the case

of transhument and sedentary breeders because of absence of mating facilities Breeders who practice seasonal breeding tie an apron around the belly of ram in the off-season to avoid mating Others tie a cord on the opening of the sheath to check mating In some areas (D.I Khan), many small farmers do not maintain their own rams, but hire them at

Rs 4 to 5 per day for 4 to 5 days A ram is usually put with a flock of 40 to 50 ewes but

in some cases as many as 80 to 90 In the bigger flocks, two or more rams may be

allowed to mate at a time In such cases the stronger ram is overused and the weaker underused and as a result some of the ewes are not mated and others are served by

overused rams and do not conceive Some breeders in Balochistan believe that breeding twice a year ensures regular milk supply for the families Rams are not allowed to breed before 2 years of age

A comparison of spring and autumn breeding seasons indicated that:

i) Fertility was 83% in autumn and 73% in spring;

ii) The number of lambs born per ewe was 1.04 in autumn but 0.88 in spring; iii) The number of lambs born per ewe conceived was 1.25 in autumn and 1.21 in

spring; and

iv) The incidence of twin births was 36% in autumn and 21% in spring

A study of the incidence of post-lambing oestrus in Lohi, Kachhi from Sindh and Awasi from Lebanon and its crosses showed that oestrus occurred:

i) In the second to fourth month after lambing, 70% Lohi came into oestrus; ii) During the same period 65% Kachhi were in oestrus; but

iii) The crosses behaved mid way between two parents

Selection is largely subjective in the absence of records such as birth and weaning

weights, fecundity, or quality and quantity of wool produced, but at public experimental farms due attention is paid to such traits Private breeders do care for growth as the larger

and heavier ram lambs would attract the attention of the breeders Lambs are allowed to suckle for 4 to 5 months Lambs are not allowed to accompany the mothers to pasture In most parts of the Punjab province, lambs accompany their mothers as soon as they are able to walk In parts of Balochistan lambs are grazed separately by children near the camp Where lambs are kept separate, suckling is allowed morning and evening after the families have removed part of the milk especially from good milkers Since white wool fetches the highest price, ram lambs with a white coat, well developed body and strong constitution are selected for future breeding Breed uniformity is keenly maintained for

an all−white body and recognized spots, if any, on the extremities The incidence of

mismothering is high in cases where lambs are kept separate from their mothers

Mismothered lambs are reared on foster ewes by forced suckling Mortality in such lambs

is high and the growth rate generally below average The shepherds of Balochistan take extra care to avoid mismothering There the flock is halted at a distance from the lamb enclosure and ewes are freed one by one to allow them to recognize their lambs when rejoining occurs The records at public sheep farms show that the incidence of

mismotheirnbg varies in different breeds (1.5 to 3%), being the highest in Kachhi breed (4 to 23%), probably due to poor mothering instinct

In most of the cases culling of sheep is not very systematic It is practised in ewes and male lambs and is generally done when the family needs money or 2 to 3 months before the annual religious occasion of Eid-ul-Azha Others avail the occasions of weekly/monthly/sheep goat markets to sell their surplus/culled stock Male surplus stock

is commonly castrated and reared to one year age and in other cases to 2 years age to sell

at high prices Culling of ewe lambs is rare The ewes are culled for broken mouths, damaged udders, permanent lameness or infertility

male

Anatomy: The most obvious part of the male’s reproductive system is the scrotum

containing the testes, which are suspended herein by spermatic cord This may vary in size according to breed but, in general, abnormally small testes are a sign of likely low

fertility The scrotum not only supports and protects the testes but also it is an important means of temperature regulation Normal production of spermatozoa occurs at a temperature 4 to 7°C lower than body temperature Thus in hot weather the scrotum will allow the testes to hang down from the wall of the abdomen and conversely when cold they will be drawn up close to the body In extremely hot weather this temperature regulatory mechanism may break down resulting in poor spermatozoa production In some goat breeds especially in some Angoras, the scrotum may be almost completely bifurcated (split purse) It is considered a fault in show animals However, this may not cause a severe fertility problem

Failure of the testes to descend into the scrotum will also cause problems of fertility One testis may not descend (called monorchid) or in some cases both may not (called cryptorchid) When purchasing males for stud, it is the most important to ensure that both testes are in place in the scrotum and that they are of reasonable size with no abnormal swellings and that they feel firm and not soft and spongy The other external sex organ is the penis In the male sheep/goat, the penis is normally retracted into a tube called the prepuce To give extra length during copulation, the penis has a S-bend known as the sigmoid flexure (Figure 8)

On the end of the penis is the thin tubular protrusion of the urethra called the urethral process When the penis is protruded from the prepuce, especially during the breeding season, the male (goat) is able, with remarkable directional accuracy, to spray urine over himself or anyone who is standing close enough

Physiology: The rams/bucks, except in temperate regions, show year round sexual

activity, especially when stimulated by receptive females Young males are particularly precocious and fertile matings have been recorded from kids of 4 months of age Males of Teddy goat breed exhibit quite a bit sexual activity at 5 to 6 months of age

Spermatozoa are formed from cells in the testes called spermatogonia These spermatogonia divide repeatedly to form spermatids, which eventually form the spermatozoa, which are discharged into the lumen of seminiferous tubules The spermatozoa travel along in fluid secreted by the tubules, until they reach the epididymis where they are stored These newly formed immature spermatozoa are immotile and are very sensitive to unfavourable temperature and nutritional conditions Full maturation occurs in the tail of the epididymis and the spermatozoa become motile during ejaculation when they come in contact with the secretions of the accessory glands (the vesicular or the seminal vesicular gland, prostate and bulbo-urethral glands) It takes about 50 days from the formation of the spermatozoa in the seminiferous tubules to the time they are stored in the tail of the epididymis During periods of intense sexual activity, this duration may be reduced as the movement of the spermatozoa through the epididymis may be speeded up

Another important function of the testes is the production of the hormone testosterone The secretion of this hormone is controlled by gonadotrophic hormones secreted by the pituitary gland situated at the base of the brain Although sexual desire in ram/buck is influenced a great deal by the presence of receptive females, nutritional status and environmental factors also play an important part

Prior to mating a ram/buck will spend varying amounts of time in courtship behaviour, which certainly is an important stimulation for both male and female During hand mating of pedigree animals, when a female is led to a specific male, it is important that

restraints are not imposed on this behaviour and the most successful results will always

be from animals that are allowed some time together in an enclosure

female

Anatomy: Unlike the male most of the female’s reproductive organs are internal and

would only be seen by attending a post-mortem examination or by obtaining the relative part of the body from a slaughtered animal The only external feature is the vulva which undergoes some changes during oestrus and when parturition (lambing/kidding) is imminent The vulva opens into the vagina wherein the male’s penis deposits semen during copulation In a normal adult ewe/doe, the vagina is approximately 7 to 8 cm in length At the end of the vagina is the cervix or neck of the uterus (Figure 9) The cervix varies in length from about 4 to 8 cm and is made up of 5 to 6 muscular rings, which effectively act as a seal between the vagina and the uterus The uterus is made up of two large tubes or horns and at the end of each of these horns are the oviducts and ovaries The ovaries change in appearance according to the stage in the reproductive cycle The eggs or ova are shed from what are called the Graafian follicles and these can be seen during a postmortem examination if they are near to maturation

When an ovum is shed, the remaining structure is called a corpus luteum, meaning yellow body, and these also can be seen on the ovary and are an indication of an ewe/doe that is ovulating normally If the ewe/doe is pregnant, the corpus luteum remains and plays a part in maintaining the state of pregnancy If she is not pregnant, the corpus luteum regresses

Physiology: The decreasing daylight triggers off breeding activity in small ruminants

The lengthening nights cause increased release of the hormone melatonin from the pineal gland within the brain It then causes the release of gonadotrophin releasing hormone, which stimulates the pituitary gland into secreting follicle-stimulating hormone (FSH)

As its name suggests, FSH stimulates the development of the follicle within which an ovum will develop and from which it will be released The onset of the sequence of events gives rise to oestrus behaviour, or heat, in an ewe/doe and the whole cycle of events is called the oestrous cycle

As the Graafian follicle matures, it secretes the hormone estrogen, which eventually stimulates the brain into triggering off the release of luteinising hormone (LH) into the bloodstream The release of LH causes the follicle to rupture and an ovum will be released into the oviduct The ovum remains viable in the oviduct for 10 to 12 hours About 30 to 36 hours before ovulation occurs, the ewe/doe will normally begin to show oestrus or heat behaviour Pheromones (specific odours) are released by the female, which also stimulate the male to sexual excitement This behaviour is a combination of signals to the male that she is at the correct period in her ovulation cycle for mating when changes in the reproductive tract, to facilitate mating, have occurred The vulva becomes somewhat swollen, copious mucus is produced and the cervix dilates

If a fertile mating takes place, the fertilised embryo develops freely in the uterus for about

21 days until implantation takes place and the embryo becomes attached to the wall of the uterus by way of the placenta The caruncles which form the points of attachment on the uterine wall are present all the time

If an ewe/doe is pregnant, the corpus luteum, formed after rupturing of the follicle, remains and produces the hormone progesterone Progesterone acts as a signal to the

brain to shut down the cycling mechanism and prepares for and helps maintain pregnancy In some animals, but not the goat, the role of corpus luteum is taken over by the placenta In case conception does not occur, the corpus luteum regresses and the level

of circulating progesterone consequently falls The cycle then starts again and a pregnant ewe and doe will continue to cycle in this way every 16 to 17 days and 19 to 21 days respectively until the end of the breeding season

This is still another approach where the elastrator rubber ring is used on the scrotum, but the testes are pushed back up into the body cavity This sterilizes the animal due to increased body heat While the male hormones are still present to increase weight gain with more lean meat, the animal shows little or no sex activity This method is used at about four weeks of age and the animal is called an induced cryptorchid (having hidden testicles) Extensive tests (Figure 10) in Australia have shown such animals gain weight faster, get to market faster and have more lean meat than either castrated or uncastrated males

ram/buck

Ordinarily a well-grown ram/buck is considered the best However, if he is a lamb/kid, use him sparingly during his first breeding season One way to conserve his energy is to separate him from the females for several hours during the day, at which time he can be fed and watered and allowed to rest One good ram/buck can handle 25 to 30 ewes/does

On a small flock where the ram/buck gets good feed, about six years of service can be expected of him On open range there may be overuse with more females per ram/buck, fighting with other males and little or no supplemental feed, rams/bucks (get run down) lose condition during the breeding season from eating so little and chasing the females They then succumb to diseases because of their low resistance If you are buying a new ram/buck, do this long enough before breeding season so that he becomes acclimated to his new surroundings Keep him separate on good feed and pasture until breeding time In case you are going to feed him a different ration than he had previously, be sure to change gradually Excess weight results in a lowering of potency and efficiency Keep him in good condition but not fat A buck may be ready to breed at about six to seven months, depending on his breed (Teddy bucks at four to five months), but it is better not

to use him until one year Use him two or three times a week from the age of one year to one and a half years

During the breeding season, feed the ram buck at least 300 g concentrate mixture per day After separating him from the bred females, a maintenance ration of at least 100 to 150 g per day, plus leafy hay as necessary during the winter should carry him through until good pasture is available again

Since summers here are very hot, therefore, provide him a cool shady place to protect from the heat An elevated body temperature whether from heat or due to an infection, can cause infertility Semen quality is affected at 100 degrees and is seriously damaged at air temperatures beyond that Several hours at that temperature may leave him infertile for weeks The scrotum of ram should be sheared before the onset of severe summer The ram/buck may be run with the ewes/does at night and in the early morning, but keep him

penned in a cool place during the heat of the noon and afternoon and provide fresh water High humidity coupled with temperature can also decrease sexual urge

A sense of smell greatly determines a ram’s/buck’s awareness of oestrus in the ewes/does A study of sex drive in rams done at a university in UK showed that some breeds of rams have keener olfactory (nose) development than others and are able to detect oestrus in ewes that goes unnoticed by other breeds

The presence of the ram/buck, especially its smell has a great effect on sexual activity of the ewes/does This stimulus is not as pronounced when the male is constantly with the females as it is when he is placed in the adjoining pasture or pen about two weeks ahead

of the breeding season Owners of large flocks often use a vasectomized ram/buck turned

in with the ewes/does about three weeks prior to scheduled breeding, in order to stimulate the onset of oestrus in the flock Be careful that at any one time not more than one normal male should be turned in with the ewes/does, otherwise there is inevitable fighting and head-butting until the boss is decided Aggressive potential and ram/buck fertility are not necessarily related However, there are reports that mating success of dominant rams/bucks does far exceed that of the subordinate ones

alternative to it?

The ram/buck marking harness is a device that helps keep track of the ewes/does who are bred It has a holder on its chest for a marking crayon Each ewe/doe is marked with the colour of crayon the day he breeds her While using a colour in the crayon, the colour of female animals be kept in view (Figure 11) Inspect the ewes/does each day and keep record of the dates so that you will know when to expect each one to give birth In case of ram use one colour for the first sixteen days he is with the ewes, then change colour for the next sixteen days and again for the next Change of colour in case of buck may be done after 18 to 19 days If many females are being re-marked, it means they were not bred the previous times he tried to breed them, since they are still coming into heat This might indicate that the breeding male was sterile If the weather was extremely hot just before or after you turned the male in, you can blame heat for it But to be on the safe side, it is better to try another ram/buck

As an alternative, instead of marking harness, use a marking paint on the ram/buck brisket (lower chest) Mix the colour with a lubricating oil or even with vegetable ghee, using only paints that will wash out of the fleece such as lamp black, venetian red The same colour will be stamped on the back of the ewe/doe indicating that it has been bred The same happens when marking harness is used

fastest-three or four year old ram/buck If it is a good one, it can be sold as a breeding male, can trade with another small ruminant raiser or can be sold for slaughter on Eid-ul-Azha The way ram lambs/buck kids are raised can have some effect on their future sexual performance Various studies have shown that rams/bucks raised from weaning in an all-male group will show lower levels of sexual performance in later life Some will actually show no interest in receptive females When you are raising a lamb/kid as a breeding male, do not pet him much or handle him unnecessarily Do not let children play with him even when he is small He will be more prone to butting and becoming dangerous if

he is familiar with you than if he is shy

sheep and goats

The period from the date an animal gets conceived to that date it gives birth to one or more newborns is called gestation period or pregnancy period It ranges from 148-152 days in sheep and goats with an average of 150 days (five months)

sheep and goats

The duration between two heat periods is called the oestrous cycle Normally each oestrous cycle has four different phases i.e proestrus, oestrus, metoestrus and dioestrus The duration of oestrous cycle on average is 16-17 days in sheep and 18-21 days in goats

Oestrus is one phase of the oestrous cycle and it denotes the period during which an ewe

or doe is receptive to the breeding male On average the duration of oestrus or heat period

in sheep and goats is 28 and 24 hours, respectively

The usual signs are nervous voices such as ‘baa baa’/bleating, slightly swollen vulva sometimes accompanied by a discharge, riding other does or being ridden by them, somewhat off feed, tail wagging and drop in milk production (in milk goats) In some cases increased but interrupted micturition is also observed At the beginning of heat, the mucus discharge from vulva will be clear, but it will turn cloudy toward the time of ovulation After the ewe/doe ovulates near the end of heat, the mucus will get thick and whitish

The optimal time varies greatly among different geographical areas It may vary even in the same country The desired lambing/kidding time may depend on the availability of pasture, local weather conditions, time restraints, labour, targeted lamb/kid markets etc It

is better to choose the lambing/kidding time that fits your priorities and plan to breed about five months before you want newborns When the cost of hay or concentrate feeding is a consideration, lambing/kidding should be timed to take advantage of new pasture growth Thus you could plan for the lambs/kids to be about five to six weeks old

at about the time of the first good early growth of pasture

early and late lambing/kidding

What constitutes ‘early’ or ‘late’ lambing/kidding will depend on climate of the given area In areas where modern husbandry practices are in operation, there with moderate winters and hot summers, the lambing/kidding is planned for autumn or early winter to maximize weight gain, knowing that newborns experience very poor weight gain in hot

temperatures On the other hand, those in far northern areas often plan for lambing/kidding during March or April in order to avoid severe winter, while those in temperate coastal climates may let the rams/bucks run with the ewes/does the year round and let nature take its course Advantages:

Early Lambing/Kidding

i) There are fewer parasites on the early grass pasture

ii) Ewe lambs/doe kids are more apt to breed as well grown lambs/kids

iii) You can have all lambs/kids born by the time best spring grass is there

iv) There are fewer problems with flies at docking, castrating and disbudding

Late Lambing/Kidding

i) It is easy to shear ewes before lambing

ii) It avoids lambing/kidding danger in severe weather

iii) Milder weather means fewer chilled lambs/kids

iv) Ewes/does can give birth on the pasture, if needed

v) Concentrate ration can be saved since there is good grazing available

A female that is bred before she matures fully may become stunted since she cannot put nutrients into both her growth and foetal development A well fed ewe/doe is ready for breeding earlier than a poorly fed one An ewe/doe should reach 70 to 75% of her mature weight before being bred Some breeds are slow maturing than others Breeding season is shorter for ewe lambs/doe kids than for mature ewes/does Teddy goats mature much earlier than other goat breeds A properly fed Teddy doe is ready for breeding at five months of age In milk goats a reasonably early breeding helps the udder develop better

In countries where early marketing of lambs for meat is practised, there the ewes who breed as lambs are thought to be the most promising as they show early maturing which

is a key to prolific lambing Ewe lambs according to their feeding practices should have attained 38 to 45 kg by breeding time as their later growth will be held back a little as compared to unbred lambs If not well fed, their reproductive life-time may be shortened

If replacement ewes are chosen for their ability to breed as lambs, the flock will improve the capacity for ewe lamb breeding, which can be a sales factor to stress when selling breeding stock

Deworm the ewes/does Trim away any wool/dung-tags from around the tail Trim their feet since they will be carrying extra weight during pregnancy Subject the ram/buck to deworming too Check all animals for ticks If you eliminate ticks before lambing/kidding, none will get on the lambs/kids and thus you will not have to treat for ticks again At seventeen days/nineteen days before you want to start breeding, put your ram/buck in a place adjacent to the ewes/does, with a good fence between them Some studies have indicated that the sound and smell of the male will bring ewes/does into heat earlier Also, a similar reaction was obtained just by fastening a ram/buck-scented pad to the ewe’s/doe’s nose

Some large flock owners have initiated the use of a vasectomized (sterilized) ram/buck to stimulate the onset of oestrus in the flock Never pen your rams/bucks next to ewes/does before this ‘sensitizing’ period just prior to breeding Remember, ‘absence makes the heart grow fonder’ It is the sudden contact with the rams/bucks that excites the females Appropriate vaccines important to both mothers and/or newborns should be timely used

Q Define flushing and explain its role in small ruminant breeding

Flushing is the practice of placing the ewes/does on an increasing plane of nutrition i.e in

a slight weight-gain situation to prepare for breeding High quality forage may be used for flushing or it can be accomplished by supplementing the usual summer diet with concentrate ration It is not as effective in animals that are already in good condition Thin females require a longer flushing period It is most productive when initiated seventeen/twenty-one days prior to turning in the ram/buck and continued tapering off gradually for about thirty days This process not only gets the ewes/does in a better physical condition for breeding, but it also helps synchronizing them by bringing them into heat at about the same time, preventing long strung-out lambing/kidding session

It is also a factor in twinning, possibly because with better nourishment the ewes/does are more likely to drop more ova Various studies have indicated that flushing results in 18 to 25% increase in the number of lambs/kids, and some farmers think it is even more You can start with 100 g concentrate mixture/head/day and work up to 300 g in the first week continue that quantity for seventeen/twenty-one days When you turn in the ram/buck, taper off the extra grain gradually The ewes/does will probably come in heat once during that seventeen/twenty-one days of flushing, particularly if you have put the ram/buck in

an adjoining place but it is preferable to have them bred in the second heat since they are expected to drop a greater number of eggs and are more likely to produce twins Flushing promotes increased ovulations, thus increasing the number of lambs/kids born

small ruminants

One of the best heat-detectors is a ram/buck wearing a breeding apron to prevent actual mating or a male that has been vasectomized A miniature version of the ram/buck rag may help detect heat Rub a piece of cloth over various parts of ram’s body or over the scent glands of a mature buck and keep it in a jar with a tight fitting lid to retain the odour During daily oestrus check, open the jar and let the ewes/does sniff the contents If one is in heat, the signs should become more obvious

Weak or silent heat, longer than normal cycles, continuous heat, shorter than normal cycles or heat signs during pregnancy are the conditions that may be termed abnormal heat Commonly known causes are anaemia, embryonic death, cystic ovaries, moldy feed and estrogen content in some legume forages (red clover/white clover has estrogen and lowers lambing/kidding percentages) For cases of anaemia, the animals should be treated for blood-sucking worms (two weeks before breeding) as well as for nutritional deficiencies Treatment is probably unnecessary when abnormal heat is due to embryonic death since either embryonic material become reabsorbed or abortion occurs If cystic ovaries are the cause, hormonal treatment can cure No treatment is necessary when heat signs are exhibited during pregnancy since ovulation does not occur

does, to have them bred?

Dairy does are usually kept separate from bucks to prevent male odour from ruining the milk and are bred annually to maximize milk flow Does bred early in the season have better lactation records and their female kids mature early enough (if well fed) to be bred the following season But it is not desirable to breed a doe during her first heat of the season Better wait until her second or third heat to avoid having kids come during the

worst part of winter or to have freshening of your does so spread as to create a continuous

milk flow

The best time to breed a doe is in the middle of heat, but it is not always easy to tell when

that occurs It seems fairly safe to take the doe to the buck as soon as you notice that she

is in heat If possible, breed her again in about twelve hours to ensure conception It is

better to hand breed which involves holding her collar or a lead The buck will cooperate

quickly and the fuss will be over soon If the buck shows little or no interest in your doe,

you may have misjudged the signs of heat or noticed them too late Virgin does are often

hard to settle Some keepers leave problem does with a stud for a full month, since bucks

have an uncanny sense for right timing If you do not own a buck, pick out a stud in

advance and make arrangements early so that you do not miss the breeding season Look

for a handsome buck that has a history of producing daughters with good milking

records/ability Preferably identify the buck and doe(s), the date they were mated and the

buck’s owner (These are requirements for registration of animals of the same

breed-purebred animals)

reproductive performance to achieve optimum numbers of healthy kids

Breeders should not depend too much on getting animals mated at the end of the season

since, all too often, the cycle before the one when mating was planned turns out to be the

last for that season Kids show sexual activity earlier than older goats and therefore, it is

unwise to leave male and females together about 4 months after their birth

The restriction of seasonal breeding is a problem to some farmers since it results in

seasonal milk production and for those who depend on milk production for their

livelihood, it is an advantage to be able to produce and supply milk all the year round

There are two ways of stimulating goats to breed out of season: one involves the

administration of hormones or analogues of hormones and the other involves the

alteration of environmental conditions, usually light to induce ovulation

The most common method of treatment involves the use of sponges impregnated with the

hormone progesterone or a synthetic version of it These sponges are inserted into the

vagina and are left to release the hormone over a predetermined period Table 10 shows

two methods commonly used French workers have recently shown that prolonged

progesterone treatment can adversely affect fertility and they advocate shorter sponge-in

method The amount of PMSG (pregnant mare serum gonadotrophin) given will depend

on the stage in the season For Method-I 600 to 700 iu are given during the non-breeding

season and 500 to 600 iu during the transitional period i.e within 2 months of the normal

cycle The PMSG is given as a source of follicle stimulating hormone (FSH) and

Luteinising hormone (LH) to increase the ovulation rate and thus to increase the chance

of conception For Method-II the same principle applies but 100 iu less PMSG is used

than for the longer sponge-in method For the shorter sponge-in method 0.1 to 0.2 mg of

prostaglandin (cloprostenol) is injected intramuscularly at the same time as the PMSG

PMSG Day 17 Day 9

* There is evidence that time of day affects fertility, the optimum time for AI being 1200 to 1400 hours, thus influencing the time of sponge removal

The purpose of prostaglandin is to cause regression of any corpus luteum that may be present, depending on the goat’s natural cycle, thus removing any endogenous progesterone (packets of sponges come with detailed instructions on how to insert them; applicators are also supplied) Care should be exercised with them as clumsy use can result in severe damage to the wall of the vagina, particularly when inserting sponges into virgin animals Nylon threads are attached to the sponges to facilitate removal These threads may be chewed off by other goats It is also possible to synchronise oestrus by injections of synthetic prostaglandin, a substance produced by the uterus of non-pregnant goats, which causes the degeneration of the corpus luteum This can only work if there is

an active corpus luteum Goats respond quickly to prostaglandin and usually come into heat 24 to 48 hours after treatment If a timed mating is required for a goat whose last oestrus is not known, two injections are given 11 days apart

Male Effect: If a male is run with females during the transitory period prior to the

expected breeding season, he will tend to stimulate the females into oestrus some 2 to 4 weeks early and they will tend to be synchronous If a selected mating of the females is intended then a vasectomised teaser male can be used In case goats failed to exhibit oestrus, a ‘billy rag’ is used This is a rag that has been rubbed over the stud male thus becoming impregnated with his very characteristic smell This rag will be kept in screw-top jar and will be brought out to be waved under the nose of a female that is not showing any signs of heat when it is thought she should Often this is enough to start a female cycling

Light Effect: Having discussed earlier that how differences in day length are the main

trigger for the onset of the breeding season, it is perhaps possible that by housing goats in late summer or early autumn in a shed that is fairly dark, to accelerate the shorterning day effect and thus the goats may well show first heat signs a few weeks earlier The role of the hormone melatonin in controlling seasonal oestrus behaviour is well known By administering melatonin, which can be done in feed, scientists have been able to induce oestrus behaviour and ovulation out of season If this technique can be used with goats, it would be extremely useful for a farm wishing to produce milk throughout the year Work done in USA has shown that out of season mating can be planned by using a controlled artificial lighting regime based on the principle of a period of long artificial days followed by a period of shorter days A system involving 60 days of 20 hours light during January and February, followed by ambient lighting from March 1, resulted in the goats showing a single oestrus period during late April through June with most showing oestrus

in May The level of light recommended was 0.3 m of 40-watt fluorescent tube per 3 sq.m of floor space with tubes approximately 3 m above the floor Those goats not mated went on to cycle normally in the autumn The increased lighting is also likely to increase winter-feeding activity, which will probably increase milk yields It was also suggested

that the males should also be kept in the same extended light conditions if they were to work satisfactorily out of season

Unlike cows and more particularly buffaloes, heat or oestrus detection in goats is not normally a problem Those with large herds, especially if there are male goats on the farm, rarely experience problems in this respect They exhibit a number of behavioural signs which in goats that are regularly handled, such as milkers, are easily recognized Those who experience more trouble in detecting oestrus seem to be those who have one

or two goats Probably in comparative isolation, the typical oestrus behaviour and the interaction between goats at this time are suppressed The most evident sign of heat is the plaintive cry that nearly all goats make at this time It is much different to their normal call and will soon be recognized once one is familiar with the normal calls and behaviour

If there are males on the farm, the plaintive crying will be accompanied with wishful looks towards the males and if they get the opportunity, the females will stand around the male’s pens showing what in human terms would be called flirting behaviour Oestrus often starts late at night thus signs might be observed early the following morning Several of the usual signs of oestrus have already been discussed elsewhere in this book

In spite of all these signs oestrus is sometimes missed When large groups of young goats are run together, it can be difficult to notice oestrus behaviour If possible it is very useful

to run a vasectomised teaser male with such groups of young goats If a sheep raddle harness is used on the male, he will mark the oestrus females when he attempts to mount them If the females are checked twice daily it will be possible to pick out those that are

in heat and these can then be taken to the appropriate stud male

The age at which an ewe/doe should first be mated will vary according to breed, their feeding and health status It is important that the young female is well grown before she

is expected to become pregnant and rear a lamb/kid If mated too young she herself will

be stunted, restricting her capacity for long and productive life Young breeders are very likely to abort or may be unable to produce enough milk for the lamb/kid, leading to nutritional stress and a high probability that the young will die However, feeding and care of an unproductive female is a burden for farmers An ewe/doe should never be mated before one year old Ideally she would have one pair of permanent incisors i.e be aged about 14 months Dwarf breeds such as Teddy goats may be an exception Exceptions to these rules would also occur in intensive systems where they are well fed and are able to develop early It is best if rams/bucks are not used for mating before one year age

The main signs of male sexual excitement are pursuing the female, pawing her with the front legs, curling back of the upper lip and usually a loud snorting sound Once oestrus has been detected, copulation takes place At ejaculation, sperm are deposited into the vagina, from where they are transported through the uterus and into the oviducts by the muscular contractions of these organs Sperm may be able to fertilize an ovum for 24 to

36 hours after ejaculation, but sooner the better, because with ageing of the sperm during this period, fertility is reduced Because the sperm has a longer (12 to 24 hours) period of viability than ovum (10 to 12 hours), it should therefore be in place in the reproductive

tract before ovulation takes place so that it is ready for the descending egg Oestrus lasts for about 24 to 36 hours in sheep Mating should take place 12 to 18 hours after the onset

of oestrus with ovulation occurring 24 to 36 hours after the onset In goats the duration of oestrus is almost 2 to 3 days and the appropriate time for mating should be 12 to 22 hours after the onset of oestrus with ovulation occurring between 24 to 36 hours after the onset

The simplest system is to let the male(s) run with the females during the breeding season and after allowing 2 or 3 cycles i.e 6 to 9 weeks, it is assumed that all females likely to

be mated will have been mated and the males can be removed Kidding will be expected over a 6 to 9 week period 150 days from when the males were first put in with the females If using this system one male will be required for every 30 to 40 females However, it is desirable that farmers should know when mating took place so that the precise kidding date can be predicted and also many people would like to put particular females to a particular male It would thus be necessary to group the females according to the male that one wanted to use These would be put together in a pen, paddock or field

To be able to time matings, a sheep raddle harness could be used and thus the females would be marked as they were mated If the goats are checked twice a day, it would be possible to record the goats mated each day If the raddle crayon is changed to a different colour every 20 days, it will be possible to detect those matings that were unsuccessful as these goats will be mated a second time 21 days after the first This mating system is exactly the same as used for most commercial sheep flocks and can be used with extensive goat system such as prevalent here

For pedigree mating and certainly where a single female is brought to a particular stud male, a hand-mating technique will be used This simply means the female will be led to the male who would normally be brought out of his pen onto a convenient level piece of ground nearby If the male is working well and the female is properly in heat, mating will usually take place very quickly However, a male may spend some time going through courtship behaviour, which may involve much rubbing against and spluttering over the female This behaviour should not be constrained in any way as this could jeopardize the chances of success

When the male mounts the female, a good sign of a successful mating is if he throws his head back as this is the normal sign of ejaculation having occurred If the male spends a lot of time rubbing and spluttering without mounting the female, it probably means the female is not in oestrus If the male has behaved like this with a number of females, his performance and ability must be suspected Whichever, system of mating is used, goats are normally fertile animals and a conception rate at the first mating of over 80% can be expected during the natural season Goats that have been induced into oestrus out of season using hormone treatment such as progesterone sponges, usually have a lower conception rate

For various reasons sheep/goat keepers may want to control the time of mating This may

be in order for lambs/kids to be born at a favourable time of year when feed is plentiful or

it may be to ensure in respect of goats that milk is available at a certain time of year In more intensive systems, farmers may want to breed their sheep/goats to take advantage of seasonal changes in the prices of sheep/goats or their products There are several methods

to control mating and the season at which kids are born

Separation of Males from Females: This requires the year round separate management

of males and females, introducing males into the flock at the time desired for mating For most farmers this method of breeding control is suitable only for goats that are housed for most of the year

Ram/Buck Apron: The ram/buck wears an apron made of leather, canvas or other

suitable material The apron tied above behind the shoulders hangs below the abdomen of the animal in front of the prepuce in such a way that if penis is extended, the ram/buck is unable to perform mating

Ram/Buck Penis String: A string is looped at one end around the testicles and at the

other around the prepuce of the ram/buck so that if the animal extends its penis, it is forced to deviate to the right or left, making copulation impossible The string must be removed for successful mating (Figure 12)

Castration: Unwanted breeding males may be made infertile by crushing their spermatic

cords using a special metal pincer called Burdizzo castrator Rubber ring method is also used but only on very young lambs/kids Castration is one method of ensuring that poor quality males do not breed In some countries it is also used to reduce the odour of the meat from male goats It will also increase both the fat content of the final carcass and the lamb’s/kid’s growth rate, by reducing the energy spent on sexual activity and fighting For ease of management it is desirable to castrate all unwanted young males if they are to

be kept beyond the age of 3 to 4 months since fertile matings have been recorded at this age

lambing/kidding dates, number of lambs/kids born and a column for remarks

A breeding chart for the day-to-day recording of mating and lambing/kidding

ng

3rd matin

g

Due date for birth

Date gave birth

No of lambs/kid

o

Goga 11.1

0.00

11-

ni

Goga 11.1

0.00

11-

11-

6-00

11-00

As can be seen in the example above (chart) that the male Goga was at fault since Mano mated successfully with Hero at 3rd mating The male Goga also did not prove successful

on Ist mating with Rano as well as Hirni, it is therefore, possible that he is no longer adequately fertile Similarly, if the chart shows that a certain female does not mate successfully even with three attempts, twice with one male and 3rd time with another male, it is then probable that she is infertile Such animals may be culled from the flock

For economic reasons it is often useful to determine whether or not an ewe/doe is pregnant Such a diagnosis can save feed as a non-pregnant animal will be fed less and also if non-pregnant there may be time to try another mating before the end of season It may also be necessary if one is buying or selling sheep/goats that are supposedly pregnant A milk test for pregnancy, developed for cows, involves testing for a metabolite produced by the placenta of pregnant animals called oestrone sulphate Since it is only produced by the placenta, false positive results do not occur A goat milk sample can be tested for the purpose after 35 to 50 days gestation

A recent development, particularly for sheep, is the pregnancy diagnosis by ultra-sonic scanning Using a rectal probe, diagnosis can be done after about 35 days gestation and if left a little longer, can usually count the number of foetuses This system works equally well with goats Diagnosis may also be made by X-ray Foetal bones show up after about

85 to 90 days and of course with a good X-ray, the number of foetuses should be clearly visible During the last 6 weeks of gestation, it is often possible to see the foetuses moving particularly when the goats are lying down At this time foetuses can be felt by firm palpation deep into the lower abdomen just in front of the udder

Genital hypoplasia also called inter-sex or hermaphroditism denotes lack of proper development of the reproductive organs It is an important cause of infertility in small ruminants especially goats (both bucks and does) It can appear in any breed, most often

in offspring of two naturally hornless goats It may also occur when one parent is horned and the other polled The gene for hornlessness some how inhibits normal development

of the reproductive organs Affected goats may have abnormal external genitals, but many are not so easy to identify A small ruminant-oriented reproduction expert, after thorough examination can identify such an animal As soon as it is identified do away with it It is useless for breeding; even its meat tastes strong and bucky

small ruminants? Discuss the case of a dairy doe

For the first three months you will see little change and it will be nearly impossible to tell whether she is pregnant Tests can provide an answer The most practicable for small flocks is to check milk or urine for estrone sulphate, a hormone produced by a living foetus that can be detected as early as thirty-five days after conception If you find that the doe is not pregnant, you may still have time to rebreed her A doe that has been bred should be dried off three months later for replenishment of depleted body reserves and so that milk production would not compete with foetal development Unborn kids put on about 70% of their weight during the last five to six weeks of gestation About a month before kidding, the doe should really fill out Start feeding her a little grain ration on the milk stand both to readjust her to milking routine and to check her udder for any

problems Two or three weeks before kidding, restrict legume roughage and calcium supplements in the rations of high producers

Older and poorly fed does tend to kid late Multiple births usually shorten the gestation period During the last week or two, the doe may develop depressed areas on both sides

of her tail and hollowness at her hips She may carry the kid(s) lower so that her pelvic bones seem sharper and her pinbones become raised Her vulva may distend Her udder may fill out If the udder of a heavy milker becomes tight and shiny, milk her out to prevent damage to the udder and ligaments supporting the udder At the end of or close to five months, the doe may become withdrawn, bleat, eat less and discharge white mucus, indicating that her time is near Clip the hair around her tail and udder Take the doe to a roomy stall (pen) where the bedding is fresh and clean for the health of both the mother and newborn She may paw the ground, lie down and get up restlessly, pant or rearrange the bedding She may lie down and not get up until her first kid is born She may labour for a few hours before she actually kids When contractions get closer together at the start

of hard labour, she will pass gelatinous strings of bloody mucus The first kid should be

no more than fifteen minutes away and the entire process should take about forty-five minutes, depending on the number of kids born, which may be two, though three or four are not uncommon A single is possible for does first kidding When parturition starts, you will see a round, dark, bulging water bag It will burst to reveal two feet with a tiny nose resting on them Soon come out shoulders, hips and hind legs Do not interfere or you will upset the doe and may cause unnecessary complications

The afterbirth or placenta usually comes out at the time of kidding or just afterwards It is

a stringy, light, thin, milky-looking membrane In a multiple birth, there may be one or more The doe may consume placenta and if she does, she will not be very hungry for the next few days Otherwise remove the placenta and burn or bury it

If you intend to build up a sizeable flock, careful selective breeding will increase its value The two basic rules of selective breeding are:

i) Never mate two sheep/goats that have the same fault, no matter how minor it seems ii) Keep sight of your goals and make every decision with those goals in mind

Goals may include improving milk production, improving quantity and quality of wool, increasing the lambing/kidding rate, improving growth rate of lambs/kids or decreasing susceptibility to certain disease conditions Breeding for appearance alone often leads to degeneration of wool and milk production or reproductive capabilities Any time you seem to be achieving your goals, raise your standards

Selection in favour of desirable characteristics involves culling against undesirable ones Unwanted hereditary defects include overshot or undershot jaw, anomalies of the teeth or joints, extra or double teats, undescended testicle(s), weak anatomical structure or incorrect conformation and colour for the breed How fast you make progress toward your goals depends on the accuracy of your records, how good your foundation stock is, the uniformity of its gene pool, the number of breeders you select from, the relationship between the traits you are selecting for and their degree of heritability Fortunately, most

of desirable traits for sheep and goats are heritable to a fairly high degree Some traits are not genetically controlled but depend on environment (nutrition, management etc.) You can reach your goals faster if you concentrate on only one trait at a time, but do not ignore all others, otherwise undesirable ones may creep in

Do not get excited by your early success, which may give you a false sense of satisfaction This is especially true if you start with unrelated sheep/goats so that your first few matings produce exceptionally fine lambs/kids, the result of hybrid vigour Only years of careful selection can make you certain of the pedigree of each sheep/goat in your breeding team and that no undesirable latent characteristics lurk in the background Selective breeding needs a whole lot of record keeping and a huge amount of patience

Q Write short notes on inbreeding, linebreeding, outbreeding and

crossbreeding

Inbreeding: Methods of selective breeding include inbreeding, linebreeding, outbreeding

and crossbreeding Inbreeding is the mating of closely related animals to develop a uniform genetic base so that eventually every sheep/goat in your flock is nearly identical

in production and/or appearance Inbreeding allows this by intensifying desirable characteristics, but it can also intensify undesirable ones if those are not carefully culled against Inbreeding brings out latent weaknesses to make you aware of their existence so that you can work toward eliminating them If after four or five generations of inbreeding, you continue to produce sound offspring, you can be more or less sure that there are no hidden genetic defects in your flock

Linebreeding: It is a form of inbreeding It aims at concentrating the blood of one

founding parent, usually a ram/buck but it may also be an ewe/doe Many books contain linebreeding charts which may be taken as suggested guidelines, because blindly plugging the names of sheep/goats into a chart only due to their position in the family tree

is likely to produce frustration Instead choose each breeder according to its individual merit and potential for bringing you closer to your goals The effectiveness of any form

of inbreeding is increased with the number of sheep/goats involved which may be divided among cooperating flock owners A large breeding population lets you cull freely to keep only animals that help you to achieve your goals Because it involves such heavy culling that inbreeding (linebreeding) is not feasible for very small flocks

Outbreeding: It is the opposite of inbreeding It involves mating animals that are not

closely related or are entirely unrelated Its goal is to combine the desirable traits of two distinct populations with an additional advantage that it produces hybrid vigour, making the offspring superior to either parent Outbreeding becomes necessary in an inbreeding programme when undesirable traits show up or when it turns out that a flock cannot be developed according to the plan because it does not carry the genes for certain desired characteristics Outbreeding involves careful selection of an animal to complement your flock with the particular characteristics you need and no undesirable ones that may spoil your programme Such a sheep/goat is most likely to be found in another flock that is inbred, preferably one with distant ancestors common to your flock

Crossbreeding: When both parents belong to the same breed, the lamb/kid is termed as a

purebred However, each parent is of distinct different breed, the lamb/kid is called a crossbred In crossbreeding you get a lamb/kid that can potentially (but not necessarily), have the good points of both the parents and is usually faster growing The value of crossbreeding can be determined in practice by comparing the lamb/kid with the two parent breeds considering particularly the factors that are of importance in your situation: body conformation, wool, milk, prolificacy, rate of growth and size Heterosis is the hybrid vigour i.e the increased hardiness and growth performance that is often found in a crossbred when it is compared to the average of its purebred parents Hybrid vigour is the

major reason for crossbreeding The other reason is to breed in such a manner as to allow the strong points of one breed to compensate for the weakness of another Individual heterosis comes from crossing two different breeds and normally results in an average of

8 kg more meat (if well fed) than by pure breeding Maternal heterosis, as reported by researchers of Ohio State University, is the crossing of a purebred ram/buck with a crossbred ewe/doe and causes on average 18% more meat produced per ewe/doe

Backcrossing: Breeding your best ewe lambs/doe kids to the same unusually good

ram/buck is called backcrossing It is a form of inbreeding The lambs/kids resulting from this mating should not be bred back to the same ram/buck

Grading Up: The use of a good purebred ram/buck on a flock of very ordinary

ewes/does and keeping the best of the resulting offspring, is called grading up If done for several years, keeping the best of the ewe lambs/doe kids and disposing off the original ewes/does, you have probably improved the quality of your flock The actual improvement depends partly on the ram/buck chosen and partly on how carefully you select the ewe lambs/doe kids that are kept for replacement

as well as Angora goats

Exact degree of heritability is not easy to ascertain due to the interrelationship of heritable characteristics as well as the complications of undetected environmental factors Estimates of heritability show the percentage of progress you can reasonably expect when breeding selected parents (Table 11)

Age at first kidding 54-77 Weaning weight 20-55

Number of kids 10

There are several ways to evaluate the worthiness of potential breeders One is to look at showring experience if you want to breed for winners But showring wins are often weighted more in favour of appearance over meat, wool producing ability or dairy

character In addition, showring placement is mostly determined by comparing the exhibited animals to each other rather than to an ideal Another means of evaluation is through classification, a system of scoring by comparing each animal to an established standard of excellence for its breed Classifiers are trained and licensed by the various sheep/goat registered associations (mostly in western world) Like showring scoring, classification involves some degree of subjectivity on the part of the judge A third alternative that provides more objective evaluation is linear appraisal This system was established (in USA) by a committee within the National Association of Animal Breeders

as a means of placing value on individual traits by using a sliding scale from worst to best It was designed to evaluate sires used for artificial insemination

Progeny testing is perhaps the most objective way to evaluate breeding animals It involves keeping track of performance of an animal’s offspring It is a form of pedigree selection and is a method of estimating the breeding value of an animal by the performance or phenotype of its offspring Progeny testing cannot be practised until after the animal reaches sexual maturity The ram/buck must be mated to a large number of average ewes/does and not a small number of highly selected females The accuracy of ram’s/buck’s estimated breeding value increases as the number of progeny with performance information increase However, this method of selection can be very expensive and greatly increases generation interval because selection of parents cannot be carried out until after offspring have been measured

Oestrus manipulation is a means to influence the occurrence of heat, which offers some advantages if you have a large flock Manipulating heat cycles helps produce a more regular flow of lambs/kids and that of milk from dairy goats by allowing groups of ewes/does to lamb/kid at the times you designate Synchronizing heat (having ewes/does come into heat together) makes artificial insemination cheaper and easier, condenses the period during which you have to be on hand for lambing/kidding and produces groups of lambs/kids of similar ages that can be more easily raised together A disadvantage is that conception rates and foetus survival rates tend to be lower during out-of-season hot summer months

Oestrus may be controlled in three basic ways One is by hormonal treatment

The second is to introduce a vasectomized ram/buck into the flock or to hang a ram/buck rag in the barn A ram/buck rag is an empty burlap sack or an old blanket that has been liberally rubbed over a mature ram or buck’s musk glands Ram/buck odour generally causes ewes/does to come into heat within about a week The third method is through light manipulation Simulating the light conditions of fall prepares rams/bucks and female animals for out-of-season breeding

A more effective but complicated method has been devised at the International Dairy Goat Research Center at Texas A & M It involves light treating does for twenty hours a day over a sixty-day period starting in early January, using one four-foot-forty-watt fluorescent tube for each forty-two square feet of floor space, hung at a height of 2.7 to 3m The does are then kept under natural light for another thirty-five days Into each pen

of six does, a buck is introduced that has also been light-treated to stimulate fertility He

is left there for sixty days during which two or three light-introduced heat cycles occur

By this method a pregnancy rate of 67 to 100% was achieved in various breeds of dairy

goats How effectively the occurrence of heat can be controlled with ram/buck scent or lighting depends on the season, the weather, your latitude, management practices and the age and breed of your ewes/does Environmental control of oestrus is easier with certain breeds than with others, for which hormonal treatment may be necessary for optimum results

Obtaining two lamb/kid crops a year (without use of hormones) seems possible Some breeds might perform better in this respect than others e.g Teddy goats have already exhibited ample capacity to produce two kid crops a year However, apart from the physiological possibility, the possibility of proper feeding of ewes/does and their offspring must be explored Because underfeeding of small ruminants in this country has definitely kept them back from utilizing their existing potential It therefore, does not appear advisable to burden them any more unless substantial feed resources are developed and made available for them The long run effect of two crops a year on reproductive span, life span of ewes/does and on lamb/kid birth weight as well as their growth rate needs to be considered

Scientists in the Utah State University have devised and tested a method to overcome the common problem of uterine debris that prevents ewes/does from breeding back early enough to have two lamb/kid crops in twelve months They infused the uterus with 200

ml saturated sucrose solution via the cervix, within four days of lambing/kidding and obtained beneficial response Sterile solution and sterile procedure are essential to avoid serious complications Any programme of accelerated lambing/kidding will require very early weaning of lambs/kids to prepare the ewes/does for their next lambing/kidding The effect of severe hot and cold weather on newborns has also to be kept in view

ruminants during the last 10 weeks of pregnancy?

Better feeding during the last 10 weeks of gestation period will influence the size of lambs/kids, the development of udder and subsequent milk yield (which is important for the newborn lambs/kids as well as for the sale of goat milk later on), female’s forage intake during lactation which is conditioned at this time, mohair yield of Angora kids and probably wool producing capacity of sheep

ruminants in the last a few weeks of gestation

The development of the udder is influenced by a number of hormones including progesterone from the ovaries, prolactin from the pituitary gland and placental lactogen from the placenta The placental lactogen is produced in greater quantities according to the amount of placental tissue Thus ewes/does carrying a number of foetuses are likely

to produce more milk than those with single foetus During the last a few weeks of gestation the udder will undergo rapid development and in case of heavy milkers may look swollen and engorged There is often a temptation to milk out a little at this time to relieve pressure but unless the ewe/doe is in obvious discomfort, it is better not to do this since it will affect the production of colostrum at lambing/kidding

ruminants? Discuss briefly

Reproduction is said to be the engine of the flock, ensuring that sheep and goats are able

to generate enough replacements for themselves, expand the flock and supply excess stock for sale The reproductive rate of both individual sheep/goats and the flock as a whole is an important determinant of the overall success of the flock It is therefore, important that reproductive problems, if any, are spotted as early as possible and action taken to remedy the situation Important measures to assess individual reproductive performance are:

Parturition Interval: The frequency with which individual ewes/does produce

lambs/kids

Litter Size: The number of lambs/kids born per ewe/doe

Preweaning Mortality Rate: The number of lamb/kid deaths up to weaning

Postweaning Mortality Rate: The number of lamb/kid deaths after weaning

In addition, consideration must be given to the question of whether there are any females that are not reproducing Some measures of reproductive performance of a whole flock may express the number of lambs/kids born either from the breeding females that were actually mated or from the potential breeding females i.e including infertile females These indicators may include the number of lambs/kids born per number of breeding females per year (lambing/kidding rate) An index that includes an estimate of preweaning mortality is weaning rate i.e the number of lambs/kids weaned per number

of breeding females per year

Problems of reproductive management can be identified and normally overcome, whereas

if deeper physiological problems are suspected, for example difficulties of hormonal nature, access to a well equipped laboratory is required Such a facility is not commonly available A series of questions might be asked when investigating the reasons why an ewe/doe is not lambing/kidding, or why the reproductive rate of a flock is poor Such questions are:

Is the ewe/doe showing signs of oestrus? It is important to check whether oestrus is being

detected properly In flocks where males are not run continuously with females, oestrus detection can be a problem, unless the owner is very alert Women and grown up members of the family associated with handling and care of the animals might help in this regard However, it is necessary to check this and also to check that the ram/buck responds normally to females Homosexual males may not do so

Females may be experiencing normal cycles, but may not show overt signs of oestrus Any of the following factors may cause anoestrus:

Poor Condition: Poor nutrition over long periods, resulting into loss of 10 to 20% body

weight can cause the ewe/doe to stop showing signs of oestrus; this is called nutritional anoestrus

Lactation: In the early stages of lactation, females may not show signs of oestrus; this is

known as lactational anoestrus

Sickness: If the ewe/doe is very ill, she may not show signs of oestrus Alternatively she

may not be cycling at all, owing to some infertility problems and thus no signs of oestrus

If the ewe/doe is showing signs of oestrus the next question is Is oestrus regular? Try to

record when oestrus occurs Sometimes oestrous cycles are very short (6 to 10 days) or very long Causes of short cycles are:

Stress: When the ewe/doe is stressed, for example during transportation The corpus

luteum may prematurely regress, causing short cycles

Ovarian Cyst: Cysts on the ovary produce estrogen, which may shorten the cycle

Metritis: Infection of the uterus after lambing/kidding may result in short oestrus cycles Mummified Lamb/Kid: If a lamb/kid becomes mummified in the uterus, it can serve to

stimulate repeated short cycles Causes of long oestrous cycles are:

Embryonic Death: The death of the embryo in the uterus

Anoestrus: Possibly due to malnutrition or disease

Hormonal Disturbance: A hormonal disturbance resulting in a persistent corpus luteum

If oestrus is being regularly shown, but there are still problems, the question arises Is the

ram/buck proven to be fertile Males may be infertile due to:

Brucellosis: Infection with brucellosis in males can result in orchitis (swollen testicles),

which can make the ram/buck temporarily infertile or permanently sterile

Physical Damage: Any physical damage to the penis or testicles can render the male

sterile Also lameness or other physical problems can make the male unable to mount a female

Over Use: Rams/bucks should not be expected to serve successfully more than one or

two females per day If a male is run with a batch of females that come into oestrus close together, he may attempt to serve them but the sperm quality would fall with each female served By the third or fourth ewe/doe of the day, the ram/buck may be effectively infertile

Hereditary Condition: Occasionally a ram/buck is born with deformed reproductive

organs, causing him to be sterile

Age: When the males grow weak through age, they may no longer be able to mount and

mate a female successfully

Homosexuality: Males reared exclusively with other males in the absence of females can

develop homosexual behaviour patterns and will not respond to females in oestrus The

next question is Is the male with the ewe/doe all the time? If the answer is no, then there

may be problems either in detecting oestrus or in mating at the correct time in relation to ovulation If the ewe/doe has to be taken for matting to a distant male, it may not be

possible for her to be mated twice at the recommended interval of 12 hours Does the

ewe/doe stand to be mated? Standing to be mated is the true sign of oestrus, however,

even if the ewe/doe is in oestrus, she may be too small to support the weight of the ram/buck

It is common in crossbreeding programmes for the ewe/doe and ram/buck to need assistance at mating The female may have to be supported while the male mounts, in order to achieve successful copulation If the answer to all previous questions is yes, but the ewe/doe is still not breeding properly, then it is time to consider the possibility that the doe is infertile Females may be infertile, either not showing signs of oestrus, or simply not ovulating at all, for one of the following reasons:

Pregnancy: If the reproductive problem reported is a recent one, consider the possibility

that the ewe/doe is currently pregnant

Previous Metritis: Infection of the uterus may occur after lambing/kidding and can leave

the female infertile

Hereditary Condition: Hereditary deformities do occur, but are rare

Age: Eventually females become too old to breed

Q What do you understand by metritis?

Normally after lambing/kidding there is a reddish discharge from the vulva for up to 14 days However, if the discharge is dark red and sticky, there may be an infection and inflammation of the uterus known as metritis A course of antibiotics normally results in full recovery, however, if chronic metritis develops, the ewe/doe may be rendered infertile

The battering ram/buck may not be considered just funny It can inflict serious, and sometimes permanently crippling injuries Keep children away from it They can make him playful and dangerous Never pet him on top of his head; this encourages him to butt Leading a ram/buck with one hand under his chin will keep him from getting his head down into butting position A ram/buck butts from the top of his head, not from his forehead His head is held so low that as he charges you, he does not see forward well enough to swerve suddenly A quick step to the right or left will help you avoid the collision

If you have a ram/buck that already butts at you, try the water cure A half-pail of water

on his face when he comes to butt After repeating a few times, a water pistol or dose syringe of water on his face suffices to check him Adding a bit of vinegar to the water makes it a better deterrent

A dangerous ram/buck that is very valuable can be hooded so that he can only see downward and somewhat backward He must then be kept apart from other rams/bucks as

he is quite helpless

Strange rams/bucks will fight when put together Well acquainted ones, will, too, if they have been separated for a while Two strong rams/bucks who are both very determined will keep fighting until their heads are bleeding and one finally staggers to his knees and

is hard for him to get up Rams/bucks will occasionally kill one another Never pen a smaller, younger one with a large dominant one To prevent fighting and the possibility

of being injured, you can put them together in a small pen for a few days In a confined area they cannot back up far enough to do any damage If no pen is available, they can be hobbled i.e fore and hind legs of the same side can be fastened with ends of a broad leather strap just above the pastern joints, leaving the legs at about the natural distance apart It discourages them from butting each other, or people, because they are unable to charge from any distance They may stand close and push each other around Hobbling also keeps them from jumping the fence In addition, clogging may be tried which simply means fastening a piece of wood to one fore leg by a leather strap This will slow down and discourage both fence jumping and fighting

It is practised in several countries such as UK, USA, Canada, Russia, Australia, Switzerland and France, but natural breeding is still more popular with large flocks because breeding by ram/buck is both easier and surer For small flock owners, in most cases artificial insemination (AI) costs about the same as stud service and for them both can be less expensive than keeping a ram/buck AI is especially important where stud rams/bucks are not available locally AI lets you take advantage of a wide range of superior rams/bucks from across the country And you can keep a closed flock to prevent the spread of diseases, since AI sires are screened for health problems transmitted through sexual contact

In several countries, more and more small flocks owners especially goat-keepers are learning how to do and many are willing to do it for others The initial investment is fairly high, but can be mitigated if a group of compatible members of a farmer’s community/club pool resources The semen storage tank is the most costly piece of equipment It is used to keep the semen at –320°F during transportation and storage After semen is selected according to the histories of stud rams/bucks (published in various catalogues), it is delivered by a bus/van in the processor’s transporting tank The breeder must have another tank for the semen, so that the processor’s tank can be promptly returned Since semen is viable only eight to twelve hours after being thawed,

in contrast to as much as two days for natural semen, it is therefore critical that insemination be well coordinated with ovulation Some breeders keep a ram/buck to stimulate ovulation and help them identify ewes/does in heat, even though they use AI to breed their animals to superior distant studs Conception rates vary between 50 and 70% Rough handling of ewes/does during AI reduces the chances of conception If you have a large flock, try to achieve oestrus synchronization before calling an AI technician to your place to do the job A record of AI should include the date, identification of ewe/doe, ram/buck, semen processor and inseminator

Certain disadvantages of AI are: i) Conception rates from AI would not be expected to be

as good as with natural mating, ii) special training and expensive equipment are required, and iii) if a trained inseminator is not located nearby then travelling costs can make the service expensive

In Britain the company Caprine Ovine Breeding Services Ltd (COBS) was formed about two decades ago to develop an artificial insemination service particularly for goats The first few years of this company were spent making preliminary arrangements and now semen can be successfully diluted and frozen in liquid nitrogen at –196°C and experienced inseminators are achieving conception rates at first service of over 60% The most common method of restraint for AI involves holding the goat’s back legs off the ground and presenting her rear to the inseminator The owner or handler stands astride the goat’s neck, facing the goat’s rear The inseminator lifts the goat by her hocks and brings her up so that the handler can hold the hocks tight up against the goat’s lower abdomen pulling her up against his chest It is best if the handler can lean into and rest his back into a corner By doing so it is possible to restrain even quite large goats for insemination The inseminator uses an instrument called a speculum to look into the vagina of the goat to locate the entrance to the cervix If the goat is at the proper stage of oestrus, the cervix may be slightly dilated and it is sometimes easy to insert the AI gun some distance into the neck of the cervix However, the muscular bands can make it difficult to insert the gun into the cervix, the semen is then splashed onto the entrance The chances of conception will be reduced if this happens

For AI through the cervix, the semen is frozen in 0.5 ml plastic straws The semen is diluted so that each straw contains approximately 120 million sperm The amount of semen collected from a male varies but averages 15 to 20 straws per ejaculate An insemination technique, using an instrument called a laproscope, deposits semen directly into the uterus through the body wall This technique allows less semen to be used to achieve conception rates at least as good as when cervical technique is used The help of

a veterinarian is required for this purpose AI programme should not be considered unless conditions/facilities such as a supply of semen, skilled staff, technical equipment and

good transport and communications as well as highly motivated farmers/goat keepers exist It may be possible to run a goat AI programme alongside a buffalo/cattle AI programme, making use of the same laboratory and technicians

In recent years the techniques for preserving fertile embryos and transplanting them into suitable recipient animals that become surrogate mothers have been considerably developed in several western countries The technique is particularly attractive for rapidly increasing the number of progeny that can be produced by one female in a single breeding season It has been used most in breeds and species that, usually for reasons of scarcity, are valuable and therefore, where the relatively high cost involved can be justified Embryo transfer involves treating a goat with a series of injections of follicle stimulating hormone (FSH) and luteinizing hormone (LH) to synchronize oestrus and to induce super-ovulation The goat is mated repeatedly throughout the peak of her oestrus period in order to enhance the chances of a large number of ova, 12 on average, being fertilized At the same time a number of ordinary goats, usually 7 to 10, are also treated with hormones so that their oestrous cycle will be exactly synchronized with that of the donor

Six days after the donor is mated, she undergoes a small operation to exteriorize the uterus, which is then flushed to recover any fertile embryos that may be present The embryos thus collected are examined under microscope by an embryologist to determine those that are fit to be used Two of these will then be transferred by a similar operation

to each of the recipient goats Embryos can be frozen and stored in liquid nitrogen in a similar way to semen and thus they can be shipped around the world and can be used a long time after they were collected When considering the economics of embryo transfer,

it is important to remember that 12 embryos recovered will not mean 12 live kids born There are many points in the programme where the embryos may die Good synchronization of the donor’s and recipients’ oestrous cycles is the most important and stress and nutrition can affect embryo survival after implantation

For every 12 embryos flushed two would probably be infertile or unsuitable for transfer Not all the recipients will be suitable for use and of the five, three or four will become pregnant Taking all these variables into account, the average number of kids born per flush will be five to six and of these, it is normal to expect 50% male and 50% female The embryo transfer requires highly skilled staff and sophisticated equipment, therefore,

it might be successfully used only under research station conditions

Culling means eliminating old and unproductive animals from the flock according to a scheduled annual or biannual programme

To know which animals to cull, you need to keep good records and this requires ear tags/tattooing Even if you can recognize each of your sheep/goats by name, still it is important to have clear records with tags than without The following records may be helpful: fleece weight of each clip/each year; wool quality; lambing/kidding record; prolapses; rejected lambs/kids; inverted eyelids; milk yield and milking ability; lamb/kid growth; foot problems; udder abnormalities; any illnesses and their treatment

At culling time review the records as well as inspect teeth, udders and feet Cull out ewes/does with defective udders, broken mouth (teeth missing), limpers who do not respond to regular trimming and foot baths or those with insufficient milk and whose

lambs/kids grow slowly There may be some exceptions to these deficiencies such as an ewe/doe who regularly has twins/triplets and passes on her prolific traits to her daughters This one may warrant bottle feeding of her lambs/kids for another season of lambing/kidding Improvements of a flock require rigid culling Consider all the points listed under purchase of new ewes/does And it is not enough to just have teeth, the bite itself is important An expert says, “They cannot shear grass if the blades do not match” Keep in mind especially the ease of lambing/kidding (to avoid animals that all require assistance at parturition time) Consideration for only growth and conformation may not

be enough, also consider survivability, mothering instinct, production of large quantities

of nourishing milk from the start, lamb/kids that find out teats, even suck out wax plug if necessary

Culling may be done at least a month before the dates of marketing shows that are held at one or two nearby places It can also be managed to coincide with the demand for sacrificial slaughter of animals, especially male stock, on the occasion of Eid-ul-Azha During the four to six weeks period after culling, the animals may be provided some supplementary ration to enhance their marketability so that they may fetch better prices