Làm giàu protein củ sắn bằng cách lên men với nấm men làm thức ăn cho lợn địa phương ở lào tt tiếng anh

HUE UNIVERSITY UNIVERSITY OF AGRICULTURE AND FORESTRY NOUPHONE MANIVANH NUTRITIVE IMPROVEMENT OF CASSAVA ROOT AND ITS UTILISATION IN TARO FOLIAGE AND BANANA STEMS BASAL DIETS FOR LOCAL PIG PRODUCTION IN SMALLHOLDERS IN LAO PDR DOCTOR OF PHILOSOPHY IN ANIMAL SCIENCES HUE, 2019 HUE UNIVERSITY UNIVERSITY OF AGRICULTURE AND FORESTRY NOUPHONE MANIVANH NUTRITIVE IMPROVEMENT OF CASSAVA ROOT AND ITS UTILISATION IN TARO FOLIAGE AND BANANA STEMS BASAL DIETS FOR LOCAL PIG PRODUCTION IN SMALLHOLDERS IN LAO PDR SPECIALIZATION: ANIMAL SCIENCES CODE: 9620105 DOCTOR OF PHILOSOPHY IN ANIMAL SCIENCES SUPERVISORS 1: ASSOCIATE PROFESSOR DR LE VAN AN 2: ASSOCIATE PROFESSOR DR TRAN THI THU HONG HUE, 2019 INTRODUCTION PROBLEM STATEMENT Pig is one of the most important animals for smallholders in the uplands of Lao PDR because it can be sold when cash is needed for buying rice and other food, for paying school fees or if a household member is sick and needs medical attention and Pork used in traditional ceremonies in households Pigs can be confined in a small area, and can covert to meet a variety of crop and kitchen wastes and give a rapid return on investment (Steinfeld, 1998) About 75% of households in upland areas are raising pig in the country (FAO, 2017) Overall, native pig around 85.1% under small holder system (DLF, 2017), they are hardy and able to scavenge at least part of their feed requirements in free-range condition, Native pigs are mainly raised in extensive lowinput systems that take advantage of naturally occurring feed (Kennard, 1996; FLSP, 2002) In most parts of Laos, agricultural by-products, such as rice bran, and natural grasses are the main feeds for live stock (ILRI 2002) In Lao villages, where most farmers are growing paddy rice for sale, the feed for pigs is based on rice bran, which is fed together with a small amount of green feed Thus rice bran is available in most farm households but they cannot support full performance because of their poor nutritive value (ILRI, 2002; FLSP, 2002) Since feed accounts for about 50-60% of the variable costs of production, feed quality is crucial to the success of pig farming operations Major problems that may result from low quality feeds are poor appetite, slow growth, high feed conversion ratio, and low survival These usually develop as a result of problems on quality of raw materials, feed formulation, processing technology, storage, and feed manage The main problem is the supply of protein as soybean and fish meals are not available in rural areas and expensive (Phengsavanh and Stür., 2006) Cassava plantation is mainly for root production The yields of root are variable depending on soil fertility, management and irrigation system Cassava root yields can be from 10 to15 tonne/ha without inputs on eroded soils (Howeler, 1991) In Laos, cassava (Manihot esculenta Crantz) known as ‘Man Ton’, it is currently the third most important crop in Laos, after rice and maize for smallholder farmers in remote upland areas Recently, the crop has become an important cash crop for either domestic use or for export because it can be used for food and feed as well as for industrial processing into starch (Ministry of Agriculture and Forestry, 2013) Cassava has become a major crop in Lao PDR mainly because of the export of starch that is extracted from the cassava root There are five cassava starch factories with a total planted area of 60,475 ha, giving an average yield of fresh roots of 27 tonnes/ha Annual production is of the order of 1.6 million tonnes (Ministry of Agriculture and Forestry, 2013) Cassava farms are needed not only for a major source of income for rural households but also for use in pig diets as energy sources because of cassava root content high levels of energy (75 to 85% of soluble carbohydrate) but low crude protein (2 to 3% CP) The root is composed of highly digestible carbohydrate in the form of starch with little fiber (Kang et al., 2015; Polyorach et al., 2013) Solid state fermentation of the cassava root is a promising technology as this has the potential to raise the protein content to levels required to balance the carbohydrate thus presenting the opportunity to make an almost complete feed for pigs (Boonnop et al., 2009) Sengxayalth and Preston, (2017a) reported an increase in true protein from to 12% in dry matter (DM) of the cassava pulp Agreement with Vanhnasin et al., (2016a) true protein increased from to 7% in dry matter (DM) of the cassava root Similar findings were reported by Balagopalan et al., (1988) who developed a solid state fermentation process for the protein enrichment of cassava flour and cassava starch factory wastes using the fungus Trichoderma pseudokonigii rifai Fermentation with yeast, bacteria has been studied for reducing non-nutritional components, increasing the nutritive value of agroindustrial by-products (Okpako et al 2008; Aderemi et al 2007; Tran Thi Thu Hong and Nguyen Van Ca 2013) Additional phosphate results in increased biomass growth of yeast and bacteria (Papagianni et al 1999) Huu and Khammeng, (2014) reported that when replacing maize with fermented cassava pulp containing 13% crude protein (DM basis), digestibility and N retention were similar to the control diet Protein enriched of cassava root (PECR) could provide in pig diets up to 25 to 28% of the dietary protein in a diet based on cassava pulp (or ensiled root), replacing ensiled taro foliage (Vanhnsin and Preston, 2016b) or soybean meal (Sengxayalth and Preston, 2017b) It similar to the growth response in pigs reported by Phuong et al., (2013) for cassava pulp enriched from to 5.5% true protein using the fungus Aspergillus niger The local feed used in smallholder systems for pigs include rice by-products, planted feeds and various green plant materials (ILRI 2002) However, the local feed contain low nutritive value Women typically are the key persons in this effort, and, with traditional practices, they spend to hours each day collecting and preparing feed for pigs (Australian Center for International Agricultural Research 2010) Farmers have little knowledge on optimizing use existing feed resources, the growth rate of the pig only 100 to 120 g/day if depend on local feed staffs In commercial complete feeds, the most common protein sources are fish meal and soybean meal These feedstuffs provide high quality protein for pigs, but they are imported and are expensive Due to their high price, such protein sources cannot be used by smallholder farmers (Phengsavanh et al., 2010) So, improving nutritive value of local feed that is abundance in their area especially the application of microorganism fermentation it is possible to improve the nutritive value of local feed and its utilization as diets for local pigs in Laos, which helps in reducing feed cost and bringing economic benefits to the farmers in rural area OBJECTIVES The overall aim of this thesis was to improve nutritive value of cassava roots by fermentation yeast (Saccharomyces cerevisiae), Urea and di-ammonium phosphate additive and its utilization as protein source in the diets of Moo Lath pigs Specific objectives were to:  To study nutritive value of casssava root by fermentation yeast (Saccharomyces cerevisiae), Urea and Di-ammonium phosphate additive   To study the limiting factor to the synthesis of true protein from crude protein in the fermentation of cassava root To evaluate the use of protein-enriched cassava root as partial replacement of taro silage in a ensiled banana stem - based diet fed to Moo Lath pigs CHAPTER 1: LITERATURE REVIEW There are main points following (i) Pig production in Laos; (ii) requirement of protein and amino acid for growing pigs (iii) feed stuffs for pig in Laos; (iv) method to improve value for feed stuff with low protein content; and (v) utilization of forage based diet for pigs CHAPTER IMPROVING NUTRITIVE VALUE OF CASSAVA ROOTS (Manihot esculenta Crantz) INTRODUCTION The major problems of small-holder pig production in upland areas of Lao PDR are high piglet mortality and low growth rates Almost all pigs are of local breed (Mou Lath), managed in scavenging systems and suffer feed inadequacy in both quality and quantity According to the survey by Phonepaseuth et al., (2010) most piglets in upland areas had a low growth rate (20-50 g/day) and high mortality (30-50%) Weaned pigs required from to months to reach live weights of 20 to 30 kg The cassava root is composed of carbohydrates and is therefore mainly a source of energy The starch content varies between 32 to 35% of the mass of fresh root and 80 and 90% of the mass of dried roots (Montagnac et al., 2009) The protein content is trivial, between and 3% of dry matter (Buitrago, 1990) One way to improve the protein content of carbohydrate-rich feeds is by solidstate fermentation with fungi and yeasts (Araujo et al., 2008; Hong and Ca, 2013) The fermentation of cassava meal with S cerevisiae enhanced the protein level from 4.4% to 10.9% in DM and decreased the cyanide content (Oboh and Kindahunsi, 2005) Solid state fermentation of the root with urea and di-ammonium phosphate (DAP) is a promising technology as this has the potential to raise the protein content to levels required to balance the carbohydrate, thus presenting the opportunity to make an almost complete feed for monogastric animals such as pigs and poultry (Boonnop et al., 2009) The problem, in the studies reported so far, is that not all the added nitrogenous compounds (urea and DAP) were converted to “true” protein, the levels of which never exceeded some 50 to 70% of the “crude “ protein in experiments with yeast-fermented cassava root (Vanhnasin and Preston, 2016a) and cassava root pulp (Sengxayalth et al., 2017a) Yeast cannot directly use urea which must first be hydrolysed to ammonia by urease However, the activity of urease is inhibited at low pH (Kay and Reid, 1934), which falls rapidly when the cassava root is fermented EXPERIMENT 1: MATERIALS AND METHODS Location The experiment was carried out in the Laboratory of the Animal Science Department in the Faculty of Agriculture and Forest Resource in Souphanouvong University The site is located km from Luang Prabang City, Lao PDR The mean daily temperature in this area at the time of the experiment was 27oC (range 22-32°C) Experimental design The experiment was arranged as a 2*3*4 factorial in a completely randomized design (CRD) with replications in each period The treatments were: Root processing Steamed (ST) and not steamed (NST) Di-ammonium phosphate DAP: 0, or 2% of root DM Procedure: Time (days) Day 0, 3, and 14 Steaming Cassava roots were peeled and chopped by hand into small pieces (1-2 cm) One portion was steamed for 30 minutes in a bamboo basket placed above a pan containing boiling water The composition of the substrates were increased the level of of DAP zero to 2% and balance N in each treatment by urea with constant of Yeast as 3% for testing the nutritive value of cassava root after fermentation The steamed cassava root was removed from the bamboo basket allowed to cool for 15 minutes The steamed and un-steamed cassava root were then mixed with urea, yeast (Saccharomyces cerevisiae) and DAP (table 1) The proportions of urea were varied according to the level of DAP so that the substrates were iso-nitrogenous The mixed substrates were then transferred to bamboo baskets covered with plastic netting to allow free entrance of air (photo 2) and allowed to ferment for 14 days Table Composition of the substrates (DM basis) Treatm ent DAP-0 DAP-1 Cassava r oot, % 95 94.3 Yeast, % DAP#, % Urea, % 3 1.7 DAP-2 93.6 1.4 #Phosphorus 20% The species of yeast is saccharomyces cerevisiae was used in the experiment S cerevisiae cells are round to ovoid, 5-10 μm in diameter It reproduces by a division process known as budding (Feldmann and Horst, 2010) Di-ammonium phosphate (DAP) contains 16% N and 20% phosphorus (P); Urea has 46% N (DM basis); yeast (S cerevisiae) contains 48.6% CP in DM Measurements On days 0, 3, and 14 samples were taken from the treatment There are four replicates in each period of the treatments (the sample did not repeated measurements in each period) and the sample were analyzed for DM, N, OM and true protein The fresh weight of the substrates in each treatment were weighed at each time interval to determine the relative amounts of substrate DM utilized in the fermentation process Chemical analysis DM, N and ash were analyzed according to AOAC, (1990) methods For estimation of true protein, g of the fresh sample were put in a 125ml Erlenmeyer flask with 50 ml of distilled water, allowed to stand for 30 minute, after which 10ml of 10% TCA (trichloracetic acid ) were added and allowed to stand for a further 20-30 minutes The suspension was then filtered through Whatman #4 paper by gravity The filtrate was discarded and the remaining filter paper and suspended substrate transferred to a kjeldahl flask for standard estimation of total N The measurements of crude and true protein were done on the fresh sample Statistical analysis The data were analyzed by the General Linear Model (GLM) option in the ANOVA program of the Minitab, (2010) software (version 16.0) In the model the sources of variation were treatments, treatment interaction and random error Turkey’s pair-wise comparison was used to determine the differences The statistical models used were: Yijk = µ +ci +dj + tk + (c*d*t)ijk + eijk Yijk are dependent variables; µ is overall mean; ci is effect of cassava root processing dj is effect level of DAP; tk is effect of time; (c*d*t) ijk is the interaction between the three factors; eijk is random error RESULT AND DISCUSSION Steaming the cassava root prior to fermentation appeared to have a slightly beneficial effect (p=0.67) on conversion of crude to true protein (table 2) Increasing the proportion of DAP from zero to 2% of the substrate DM increased the average level of true protein from 4.16 to 5.85% in DM (table 2) The level of true protein in the substrate increased with a curvilinear trend (R = 0.98) from 2.3 to 6.9% in DM as the fermentation time increased from zero to 14 days; the crude protein was 10.5 in DM after mixing the substrate and did not change at the end of the fermentation time The ratio of true protein to crude protein increased from 24.6 to 63.7 over the same period (table 2; figures and 2) However, according to (Vanhnasin and Preston, 2016b) showed the DM, CP and TP of cassava root fermented (14 days) without ingreedients were lower such as: (DM 29.5%, CP 3%, TP 1.5% but the value of Ash was hight (97%) Table Mean values for DM, OM, crude protein; true protein and ratio of TP/CP at different stages of the fermentations (% in DM) DM OM CP TP TP/CP Steaming (ST) ST 28.45 87.25 10.40 5.15 NST 30.34 87.58 10.37 4.90 SEM 0.344 0.929 0.068 0.039 p 0.008 0.812 0.806 0.004 DAP, % in DM 29.89 87.14 10.13b 4.16c 29.52 87.78 10.53a 5.08b a 28.78 87.32 10.50 5.85a SEM 0.422 1.138 0.084 0.047 p 0.247 0.921 0.025