Encyclopedia Of Animal Science - Agroterrorism potx

Agroterrorism Luther Tweeten Agricultural, Environmental, and Development Economics, The Ohio State University, Columbus, Ohio, U.S.A. INTRODUCTION Agroterrorism is the willful, unlawful threatened or actual destruction of property or people through the agricultural and food industry to achieve the perpetrator’s ends, usually political. The ultimate target may be food consumers. Agroterrorism (or any other form of terrorism) is a tool of choice in asymmetric power situations, where the perpetrator perceives an inability to achieve ends through conventional political, market, judicial, or educational channels. Terrorist threats and acts are a form of propaganda designed to achieve a political end by striking fear in people. Among the many forms of agroterrorism, random killing of many innocent people is especially effective in striking widespread fear. Because everyone eats every day, some experts conclude that the agricultural and food industry is an attractive venue through which the general population can be terrorized. The following paragraphs outline the threat and means to counter it. UNDERSTANDING AND ADDRESSING THE AGROTERRORIST THREAT This section outlines characteristics of agroterrorists, their possible targets, and means to respond to the threat. The following observations characterize agroterrorism in the U.S.A.  Among industries, the agriculture and food system has been the most frequent target of terrorists in the past decade or longer.  Agroterrorists have been home grown. Approxi- mately 100 acts of agroterrorism have been committed each year by persons from just two American organizations, the Animal Liberation Front (ALF) and the Earth Liberation Front. Radicals from other groups such as People for the Ethical Treatment of Animals have engaged in petty acts of terrorism, such as throwing paint on fur coats. The only international agroterrorism activity in the U.S.A. has been by the North American ALF of Canadian origin. The organization specializes in releasing animals from their cages on fur farms. Turning thousands of mink loose from a fur farm to fend for themselves is a disaster for local animals edible by hungry mink, and eventually leads to the starvation of many of the freed mink. The paradox is that any means such as stark cruelty to animals are justified to attain the ends sought by the presumed animal-loving zealots.  Agroterrorism has been directed more at destroying intellectual and physical property than at killing people. Standard fare includes bombing of offices, laboratories, and experimental plots engaged in developing genetically modified organisms with recombinant DNA. Terrorists ha ve tried to shut down the use of animals to test medications, surgical techniques, and cosmetics before they are used on people. Terrorists have destroyed buildings and machines that they believed to be encroaching on the wilderness. They have spiked ‘‘old growth’’ trees to protect them from logging. It is not possible to dismiss the varied activity of agroterrorists as mere pranks because those who intend only to destroy property and science end up destroying lives both literally and figuratively. A recent example illustrates the tactics. [1] On May 19, 2005, University of Iowa President David Skorton reported on a November 2004 attack on university animal research laboratories by the ALF. More than 300 rodents were removed, equipment was smashed, and acid was poured on equipment and papers, causing $450,000 damage. The ALF opera- tives sent e-mails to local and national media listing the names, home addresses, and spouse’s names of faculty who conducted the animal research. The names of graduate assistants and lab assistants also were listed. The purpose was to encourage the public to harass the named individuals. President Skorton called the ploy ‘‘[B]latant intimidation [that] was also successful, as these individuals are still being harassed and are still concerned about their own safety as well as their families’.’’ Terrorists had created a climate of fear; researchers ‘‘ are still concerned about allowing their children to play in their own yards’’ said Skorton.  The agriculture and food sector comprised as it is of millions of acres and animals is readily vulnerable to attack by domestic or intern ational terrorists. Fail-safe protection is prohibitively expensive. Encyclopedia of Animal Science DOI: 10.1081/E EAS 120041359 Copyright # 2006 by Taylor & Francis. All rights reserved. 1 Ap 905 Since the ‘‘9/11’’ devastation wrought by Islamic radicals, Americans are especially concerned about an attack on the agriculture and food system by an international terrorist group such as al Qaeda bent on killing hundreds if not thousands of people. Is such an attack likely? On March 20, 2005, the Food System Insider pub- lished the results of a survey of their readers. Some 56% of respondents said they believed ‘‘ there would be a serious case of agroterrorism in the United States in the next three years.’’ As for the likely target of agroterrorism, 33.3% said food processors, 16.7% said farms/ ranches, 13.6% said feed yards, 12.1% said the trans- portation system, 7.6% said food services/restaurants/ cafeterias, and 4.5% said retailing. These responses are not scientific but are consistent with the earlier con- clusion that the agriculture and food sector is vulnerable to terrorists, in part because it is difficult indeed to anticipate the time, place, and method of attack over a highly dispersed industry. Targets of Opportunity Al Qaeda seeks the spectacular act to strike fear; does the agric ulture and food sector offer such targets? Given a lack of examples of actual pathogen agroterrorism from history, it is well to examine the cost of (damage from) selected pathogen outbreaks from nature. Terrorists did not originate these outbreaks, but the examples could serve as a model for some future attack. Time and place Pathogen Cost or damage a Ireland 1848 Potato blight Starved millions Canada 1951 1953 FMD (Foot and Mouth Disease) $2 billion U.S.A. 1970 Southern corn blight ? U.S.A. 1993 Cryptosporidium (Milwaukee) ? U.K. 1996 Mad Cow Disease $4.2 billion U.K. 2001 FMD $5.9 12 billion Taiwan 1996 1997 FMD (swine) $7 25 billion Netherlands 1997 1998 Swine Fever (cholera) $2.3 billion Canada 2002 Mad Cow Disease $2.5 billion (1 cow) U.S.A. 2003 Mad Cow Disease $3 4 billion (1 cow) b The foregoing data [2,3] indicate that the human and economic cost of pathogen infestation can be high. A conscious, planned effort by agroterrorists to spread foot and mouth disease or mad cow disease over a wide area before it could be detected could cause damage far in excess of the numbers shown above. Responding to the Threat Agroterrorism by animal rightists, radical environmentalists, antiglobalists (opposed to multinational firms such as McDonalds), and neoluddites (opposed to new technologies such as bioengineering) has become commonplace and will continue. [4] Agroterrorist organizations representing these causes operate throughout the U.S.A. and Western Europe, but on a decentralized basis from individual cells. That fragmented structure makes it more difficult for law enforcement agencies to apprehend the terrorist ‘‘foot soldiers’’ and their leaders. Such radical groups need to be taken more seriously than in the past. The emergence of al Qaeda and other murderous Islamist terrorist groups adds a new dimension because of their determination to inflict massive economic and human losses on America. At present, the issue is how to respond. Here are some suggestions.  Agroterrorism or any other form of terrorism is abominable, but it is important to recognize that terrorists sometimes have legitimate grievances. These grievances need to be addressed expedit iously through the political system or other means. Responses could range all the way from ending some cruel animal treatment practices in the case of animal rightists to promoting a peaceful settlement of the Palestinian Israeli conflict in the Middle East in the case of Islamist jihadists.  Enjoin the propaganda war for the hearts and minds of people. Terrorists are recruited and driven to acts of violence by inflammatory speech (including literature) and firebrand leaders. ‘‘Education’’ should not be left to the radicals. Incendiary propaganda needs to be countered by strong, objective educational programs reaching the target audience. Leaders in the target audience need to be enlisted where possible to provide objective information to followers.  That agriculture and the food supply are highly vulnerable to attack from terrorists is a cause for neither panic nor complacency. Our highly dispersed agriculture is not easy to shield from terrorists but the dispersion also makes it difficult to kill lots of people. Tainted food from one location is likely to be detected before being consumed by large numbers of people. Pathogens in the water a A range of cost is included in several instances because of disagree ment in estimates among the sources. The cryptosporidium parasite outbreak in Milwaukee is included although it may have come from the feces of deer or other wildlife getting into the city water supply. The source conceivably could have been farm animals. b Cost in the first quarter of 2004 alone. Another cow tested positive for MCD in 2005. 2 Agroterrorism Ap 906 supply or nuclear weapons employed in cities would inflict more casualties. Terrorists are more likely to be American environmentalists, animal rightists, or neoluddite radicals inflicting economic terror than sent by al Qaeda to kill people.  One of the best pieces of advice is to be alert. Terrorists ‘‘case’’ targets before acting. Report suspicious behavior to the police. Good neighbors watch out for each other.  Know likely targets. Candidates include Con- centrated Animal Feeding Operations; fur farms; biotech offices, laboratories (especially those using animals in research), and experimental plots; commercial activity ‘‘infringing on nature,’’ and new machinery likely to displace many workers.  The Animal Identification System currently being introduced in the U.S.A. is useful for trace back of food pathogens to their source, whether the source be terrorists or an unsuspecting farmer or rancher.  Secure tools used by agroterrorists. It is no more possible to stop a determined terrorist than a determined burglar from entering your premises. However, making entrance difficult can discourage a burglar or agroterrorist. One stops terrorists like one stops burglars, except it is especially important to keep terrorists away from spray airplanes, ammonium nitrate fertilizers, poisons, explosives (dynamite), and petroleum fuels. W hen hiring workers, it makes sense to learn their background.  Know whom to contact. Keep telephone numbers handy to contact police, firefighters, veterinarians, medical facilities, and the local extension service agent. The latter provides liaison to crop and livestock specialists who have the expertise and tools to diagnose and contain pathogens that might be spread by agroterrorists.  Enforce laws. Domestic as well as foreign terrorists and the networks supporting them need to be brought to justice. Terrorist cells need to be infiltrated. Institutional support at the state and federal level is essential to back up local responses. In the case of livestock, veterinarians are a critical line of defense. Local veterinarians need he lp from state and federal animal health specialists to be knowledgeable regarding most likely diseases, chemical, and biological agents used by terrorists, equipment and expertise for detecting such agents, and responses essential to contain and remediate damage. The local agricultural extension agent will have access to the state plant pathologists who diagnose and remediate problems with plants, much as the animal specialists handle problems with animals. Some state agency such as the Department of Agriculture needs to be designated by the state governor as the lead agency working with the individuals and groups listed above and the state emergency management ag ency to plan and coordinate efforts to avoid or respond to agroterroris m. CONCLUSIONS The food and agricultural sector is vulnerable to attack by agroterrorists. The principal threat is from the domestic radicals inflicting damage mainly to property. An emerging threat is international jihadist groups bent on killing large numbers of people. The latter prefer concentrations of people characteristic of cities. Eternal vigilance is in order. Also in order is to remem- ber that terrorists ultimately have always been losers, even if they have had some short-term success. REFERENCES 1. Norman, J. At U of I, scientists fear animal extre- mists. Des Moines Register 2005, May 19, 1A 13A. 2. CAST. Global Risks of Infectious Animal Diseases; Issue Paper 28; Council for Agricultural Science and Technology: Ames, IA, February, 2005. 3. Henderson, J. FAQs about Mad Cow Disease and Its Impacts; Cent er for Study of Rural America, Federal Reserve Bank: Kansas City, December 2003. 4. Tweeten, L. Terrorism, Radicalism, and Populism in Agriculture; Iowa State Press: Ames, 2003. Agroterrorism 3 Ap 907 Dairy Cattle: Waste Management Deanne Meyer Department of Animal Science, University of California, Davis, California, U.S.A. John Menke State Water Resources Control Board, Sacramento, California, U.S.A. Wendy Powers Department of Animal Sciences, Iowa State University, Ames, Iowa, U.S.A. Joseph P. Harner, III Department of Biological and Agricultural Engineering, Kansas State University, Manhattan, Kansas, U.S.A. INTRODUCTION Commercial dairy operations involve breeding of dairy animals (cattle herein) to produce milk for human consumption. Operations may have more than two categories of animals. All operations will have lactating (milk producing) and nonlactating (dry) cows. Replace- ment heifers (bred or unbred fema les an d preweaned calves that are still consuming milk or milk replacer) may be housed at the facility or at a separate facility designed explicitly for the care and rearing of young animals. Additionally, mature bulls used for breeding, or young bulls not yet used for breeding, may be present. In the U.S. dairy industry, the number of cows has decreased from 11 million to 9 million in the last two decades. The average herd size in the U.S.A., and especially in California, has increased from 40 to 100 and from 200 to 788 cows, respectively, during the same time period. The number of herds has decreased from 269,000 to 91,000 herds in the U.S.A. The trend for concentrating animals at a given location is in part a fun ction of an economically viable production unit, given the opportunity costs of associated land and farming enterprises. Herds that are smaller in number can be viable when land is debt free, intensive inputs are not used, or niche markets are established. Larger herds are necessary when land and facilities are being paid for, land prices are very high, and intensive management is needed to maintain or improve neighbor relations. The necessity of environmental stewardship is greater as herd size increases. MANURE AND WASTE STREAM PRODUCTION Average manure (feces þ urine) production and characteristic values are available from the American Society of Agricultural Engineers Standard D384.2 (partially listed in Table 1). The 2004 revision of the table provides mean values based on defined dietary intake parameters as well as regression equations to allow for development of site-specific information that would assist in designing a suitable nutrient management plan. In addition to manure excretion (feces þ urine), the waste stream can contain bedding (sand, newspa- per, rice hulls, sunflower hulls, recycled dry manure, sawdust), parlor generated water associated with udder hygiene, cleaning milking equipment, or flushing; spilled or residual feed; rain runoff; foreign material; and trace amounts of medic inal or sanitary compounds. Daily milk center wash-water (nonflush sy s tem) ranges from 19 3 8 to > 568 L=cow=day, when a fl ush system is used. [1] Recent studies on California dairies indicated average parlor water use of 319 L=cow=day (Æ170) with a range from 170 to 746 L=cow=day. Attention to water use is critical to successfully design a liquid storage containment. COLLECTION Manure can be collected as a solid from corrals or mixed with bed ding, as a semisolid if collec ted from freestall lanes where significant bedding was used, as a slurry when vacuumed or scraped and little bedding or feed input exists, and as a liquid when flushed. STORAGE The method of storage is defined by the form of manure. Manure storage must be managed to minimize nuisance issues (odor, flies, etc.). Solids can be treated or stacked. Semisolids, slurries, and liquids need to be Encyclopedia of Animal Science DOI: 10.1081/E EAS 120023827 Copyright # 2005 by Taylor & Francis. All rights reserved. 1 Ap 908 collected in containers or retention=treatment ponds. Collection of manure as a slurry versus liquid increases the nutrient density and reduces the volume of material important for off-site trans portation. Storage structures are not present under the animals in typical dairy operations in the U.S.A. Size of the storage structure depends on the amount of material generated in a day, the number of days required for storage, runoff from the rainy season, capacity to hold runoff from a 25-yr, 24-hr storm, residual sludge or material in the structure at the beginning of the storage period, site specific needs, and an added safety factor. TREATMENT AND UTILIZATION Numerous companies are venturing into the manu re treatment arena. Companies may provide a proprie- tary technology for use (they maintain ownership) and they own and are responsible for the end product. Other companies have a turnkey system to treat manure. Some of these are in the development stage. Others have a long (positive or negative) track record. The most detailed list of effectiveness of treatment technologies was prepared by Humenik. [2] Solid liquid separation is practiced to reduce water content of solids to enable a more efficient export, remove solids from liquids so that smaller particles will be present in irrigation systems, or reduce volatile solids loading to a treatment pond, thereby enabling greater productivity from the pond. Although some solids are removed by the traditional gravity separation screens, these screens remove relatively little nitrogen (N), P, or salts. These nutrients are soluble and predominantly remain in the liquid fraction. Gravity flow settling basins or ponds, or a custom made, large surface area, weeping wall system removes more solids compared with traditional screens. [3,4] Another highly effective method of separation is keeping solids out of liquids when possible. When compared to other separation techniques, scraping or vacuuming to collect freestall manure or bedding material as and when the weather permits, instead of flushing all manure into liquid storage, may result in higher annual solids removal. Chemical additives and flocculants have been tried to improve solid liquid separation and P nutrient removal. Chemicals (Alum, other acids, or poly acryl- amide) have been added to manure to enhance the formation of flocculants. This was successful under laboratory conditions. Flocculants have not been successful at farm level because of the costs, additional resources needed to manage the treatment system, and minimal disincentives when excessive P is applied on the land. A few commercial ventures utilizing floccula- tion or precipitation that is followed by dissolved air flotation (DAF) exist. Presently, these technologies are still in the experimental phase for dairy manure. Enhanced biological P removal (EBPR) as a nutrient removal technique for dairy manure is being evaluated. [5] Acetic and propionic acids are the preferred energy sources for P accumulating organisms and are a critical factor in EBPR. Composting can be a n effective manure treatment. Benefits of on-farm composting include impro ved manure handling, decr eased manure hauling costs, improv e d land application ability, stabilized N, decreased weed seed viability, reduced risk of pollution and nuisance complaints, and pathogen destruction. Drawbacks of this type of composting include atmospheric emissions of gaseous compounds, loss of N, and resource utilization (labor, equipment, a nd land must be dedicated to this act ivity to maintain a consistent quality of the product). An excellent resource for on-farm composting is available. [6] A key objective of anaerobic digestion is to collect and degrade organic material (solids) in an anaerobic environment and to capture the methane gas and con- vert it to electricity. Anaerobic digestion in a controlled environment can be beneficial to reduce odor. Gases are formed within a structure (not released to the atmosphere) at a pH near 7, where methane production should be near optimum and there should be minimal formation of malodorous compounds. Gases formed are collected and they undergo combustion to yield electricity. Anaerobic digestion is not an effective treatment technology for reducing total N, P, or salts. There are numerous resources available. The USEPA maintains a website for location of vendors, equipment, etc. (http:==www.epa.gov=agstar=resources.html). Table 1 Manure production and characteristics from the American Society of Agricultural Engineers Standard D384.2 Category Moisture (%) Total manure (kg/head/day) Total solids (kg/head/day) N (kg/head/day) P (kg/head/day) K (kg/head/day) Lactating cow (40 kg milk=day) 87 69 8.9 0.45 0.078 0.10 Dry cow 87 38 4.9 0.23 N=AN=A Replacement heifer 440 kg 83 48 3.7 0.12 0.020 N=A N=a, new data not available. 2 Dairy Cattle: Waste Management Ap 909 On-Farm Biogas Production-NRAES-20 is available from the Northeast Regional Agricultural Engineering Service, 154 Riley-Robb Hall, Cornell University, Ithaca, New York 14853, U.S.A. [7] Leggett, Graves, and Lanyon [8] prepared a publication identifying many important questions to ask and answer prior to instal- lation of an anaerobic digestion system. Gasification of manure is receiving greater attention from commercial companies. The primary objective is the destruction of manure without causing air pollution while yielding energy. The remaining ash is of high quality. The end disposition of the ash is yet defined. This type of technology should contain N, P, and salts in the ash. The primary utilization of manure nutrients is as a fertilizer or soil amendment. Effective utilization of manure necessitates sampling manures, soils, and crops for nutrient composition, establishing a nutrient mass balance for the production and crop areas, and identifying alternative outlets when excessive nutrients are sequestered at a facility. CONCLUSIONS Dairy operations have increased and will continue to increase in size. The increased concentration of animals at facilities will result in a more stringent scrutiny of regulations and an increased need to manage manure so as to prevent nuisance and utilize nutrients appro- priately (protective of surface and ground water and air resources). Animal housing dictates manure collection and storage to a great extent. Treatment= utilization technologies=methodologies include mecha- nical, gravity, or chemical separation, composting, anaerobic dig e stion, gasification, and land application. The primary disposition of manure nutrients is land application. REFERENCES 1. United States Department of Agriculture. In Natural Resources Conservation Service USDA SCS Agricultural Waste Management Field Handbook, 1992. 2. Humenik, F. Manure Treatment Options in Live- stock and Poultry Environmental Stewardship Curriculum, 2001; Chapt er 25; Midwest plan service, Iowa state, Amer. Available through http:== www.lpes.org. 3. Meyer, D.; Harner, J.P., III; Powers, W.; Tooman, E. Manure technologies for today and tomorrow, Proceedings of the Sixth Western Dairy Manage- ment Conference, Mar 12 14, 2003; Kansas state university: Manhattan; KS, 185 194. 4. Meyer, D.; Harner, J.P., III; Tooman, E.E.; Collar, C. Evaluation of weeping wall efficiency of solid liquid separation. Appl. Eng. 2004, 20, 349 354. 5. Yanosek, K.A.; Wolfe, M.L.; Love, N.G. Assess- ment of enhanced biological phosphorus removal for dairy manure treatment in the animal, agricultural and food processing wastes. Proceedings of the Ninth International Symposium, Raleigh, NC, U.S.A., Oct 11 14, 2003; Burns, R., Ed.; ASAE Pub #701P1203, 2003; 212 220. 6. Rynk, R. On-Farm Composting Handbook; NRAES-54; Northeast Regional Agricultural Engineering Service, Cornell University: Ithaca, NY, 1992; http:==www.nraes.org. 7. Parsons, R.A. On-Farm Biogas Production; NRAES-20; Northeast Regional Agricultural Engineering Service, Cornell University: Ithaca, NY, 1984; http:==www.nraes.org. 8. Leggett, J.; Graves, R.E.; Lanyon, L.E. Anaerobic Digestion: Biogas Production and Odor Reduction from Manure, G-77; Pennsylvania State University: Pennsylvania, U.S.A., 1995; http: ==www.age.psu. edu=extension=factsheets= g = G77.pdf. Dairy Cattle: Waste Management 3 Ap 910 Eggs: Composition and Structure Richard E. Austic Department of Animal Science, N.Y.S. College of Agriculture and Life Sciences, Cornell University, Ithaca, New York, U.S.A. INTRODUCTION The avian egg is one of the richest and most balanced sources of nutrients among all of the foods available to mankind. Its biological function is to support the development of the embryo from fertilization to the emergence of the newly hatched chick. The structure of the egg is such that it maintains an aseptic ‘‘milieu’’ for embryonic development. It protects the embryo from physical trauma, allows for the exchange of respiratory gases between the embryo and the environment, and provides the embryo with all of the nutrients that are needed for growth and development. Eggs are generally similar among species of birds, but they can differ in some aspects of their physical and chemical composition. This article briefly describes the physical structure, chemical composition, and nutrient content of the egg of the chicken, Gallus gallus domesticus. EGG STRUCTURE The phy sical features of the egg are illustrated in Fig. 1. The relative proportions of the parts as reported by Shenstone [2] are shown in Table 1. Most of these features can be observed by visual examination of the broken-out egg, but all major compartments of the egg also have unique microstructures that can be seen with the aid of the electron micro- scope. The genetics, age, and diet of the hen, size of the egg, and environmental factors influence the relative proportions of albumen and yolk in the newly laid egg. [3] Yolk The yolk is an ov um, a reproductive cell complete with a cell membrane. The cell is so large that it would not remain as a discrete body if it were not for the vitelline membrane that surrounds it. This membrane is a bilayered extracellular structure that is secreted by the ovarian follicle and the oviduct. [2] The surface of the yolk in the fresh egg appears uniform except for the presence of the blastodisc. The blastodisc of the unfert ilized egg is easily observed as a small white spot, ap proximately 2 mm in diameter, on the surface of the yolk. [4] It is larger, 3 4 mm, in the fertilized egg [2] because the embryo usually has progressed to the gastrulation stage by the time of oviposition. The latebra is a small sphere of white yolk in the center of the yolk extending with a narrow neck of this unpigmented yolk to the blastodisc. The con- centric rings that are shown in Fig. 1 are not visib le to the naked eye. They have been observed in specially stained eggs and are believed to represent alternating layers of yellow yolk that is deposited during the day when the hen is consuming feed and white yolk that is formed at night when the hen is not eating. Carote- noid pigments are responsible for the yolk’s yellow color. [4] These pigments are present in ingredients such as yellow corn, corn gluten meal, and alfalfa meal in poultry feeds. [5] Egg yolk is composed of particles that are suspen- ded in a liquid phase containing low-density lipoproteins, livetins, several vitamin-binding proteins, yolk transferrin, and salts. [2,4] The largest particles are spheres of white and yellow yolk that range in diameter from 50 to 100 mm. These con tain inclusions that are numerous in yellow spheres but limited to one or two inclusions per white sphere. Yolk contains an abun- dance of small particles, known as insoluble yolk globules, which range in size from less than one to several microns in diameter and are enveloped in multilamellar membranes. Yolk also contains granules that are about 1 mm in diameter and contain lipovitel- lins, low-density lipoproteins, and phosvitin. Phosvitin binds calcium, magnesium, and trace minerals and has antioxidant properties. Abou t 90% of the iron in yolk is bound to this protein. [2,4] Albumen Albumen, or egg white, is the clear fluid surrounding the yolk. Although it might appear quite uniform in structure, it actually contains four compartments: a thick gelatinous region (the firm albumen), bordered medially by the inner thin albumen and surrounded peripherally by outer thin albumen. The chalazi ferous layer is the fourth compartment. It consists of a thin layer of mucinous fibers that surround the yolk and Encyclopedia of Animal Science DOI: 10.1081/E EAS 120019584 Copyright # 2006 by Taylor & Francis. All rights reserved. 1 Ap 911 are anchored in the firm albumen in the large and small ends of the egg. These anchoring regions, the chalazae, hold the yolk in the center of the egg. They appear as whitish appendages to the yolk in the broken-out egg. More than a dozen albumen proteins have been identified. [2,4] All are sources of amino acids for the developing chick embryo. Many have unique properties such as inhibiting proteolytic enzymes (e.g., ovo - mucoid and ovomucin), cau sing lysis of gram-positive bacteria (lysozyme), binding certain B-vitamins (biotin-, thiamin-, and riboflavin-binding proteins), and binding iron (conalbumen). The gel structure of firm albumen stems from the presence of at least two glycoproteins, alpha- and beta-ovomucin, possibly in asso- ciation with another protein, lysozyme. [4] Egg whites gradually become thinner during storage and eventually lose their gel structure. This may be related to the gradual loss of carbon dioxide from the egg and the resulting increase in pH of the egg white. Shell Membranes The inner and outer shell membranes surround the egg white. The inner membrane is about one-third the thickness of the outer membrane. It separates from the outer membrane in the large end of the egg after oviposition. This occurs as the egg cools and its contents contract after oviposition. Air enters through pores in the large end of the egg to form the air cell, which further increases in size over time owin g to the loss of moisture from the egg. The outer shell membrane contains the sites of mineral crystal formation during the process of egg formation. Electron Fig. 1 The parts of an egg. (From Ref. [1] .) Table 1 Proportions and solids contents of egg structures a Percent of whole egg Range of values Percent solids Shell b 10.5 7.8 13.6 99 Yolk 31 24.0 35.5 52.5 White (whole) 58.5 53.1 68.9 11.5 Outer thin white 13.5 11.2 Firm white 33.3 12.4 Inner thin white 9.9 12.6 Chalaziferous layer 1.2 15.7 Chalazae <0.5 nd c a (Adapted from Ref. [2] .) b With membranes and cuticle. c Not determined. 2 Eggs: Composition and Structure Ap 912 microscopy has revealed that the egg shell is embedded in the outer shell membrane. [6] Egg Shell The egg shell contains about 2 g of calcium and consists of columns of calcium carbonate crystals that extend outward from the outer shell membrane. An organic matrix is deposited in the areas of crystal growth during egg-shell formation. The matrix repre- sents only 2% to 3% of egg shell weight but is believed to be important in the growth of the crystalline structure of the egg shell. [4] Several thousand channels exist from the outer surface of the egg shell to the shell membranes. These channels, or pores, represent spaces between the columns of calcium carbonate crystals. [6] They are more numerous and greater in diameter in the large end of the egg. The outer surface of the mineralized portion of the egg shell is covered with a pro teinaceous coat, the cuticle. The cuticle provides the gloss y sheen that is normally visible on the newly laid unwashed egg. It probably functions to plug the openings of the pores on the surface of the egg shell to prevent the entry of microbes into the egg. NUTRIENT CONTENT OF EGGS The egg is a rich source of nutrients. [7,8] Eggs contain about 6.5 g of protein (Table 2). The protein is highly digestible and contains an excellent balance of amino acids. Egg protein has been used traditionally as a standard protein of high biological value, against which proteins from other sources are measured. Yolk and albumen contribute about 40% and 60% to the total protein of the egg. The edible part of the egg contains about 5 g of lipids. These are found almost exclusively in the yolk in the form of lipoproteins. About 70% of the lipid is triglyceride and about 30% is phospholipid. [4] Phoshatidylcholine (lecithin) and phosphatidylethanolamine (cephalin) account for ab out three-quarters and one-fifth of the phospholipid fraction, respectively. Yolk phospholipids include small quantities of lysolecithin, phosphatidyl- serine, sphingomyelin, and phosphatidylglycerol. [2,4] Eggs contain cholesterol, about 212 mg in a 60 g egg. Small amounts of free glucose are present in the egg, but most of the carbohydrates of the egg exist as components of glycoproteins. Yolk lipids are rich in monounsaturated fatty acids, particularly oleic acid, and contain substantial quantities of polyunsaturated fatty acids. The fatty acid composition of eggs reflects the hen’s feed. The typical feed is based on corn meal, soybean meal, and a small amount of supplemental animal, vegetable, or animal vegetable fat blend as the sources of fatty acids. The polyunsaturated fatty acids in these ingredients are predominantly of the omega-6 series (e. g ., linole i c and arachidonic acids). Eggs enriched in fatty acids of the omega-3 series (e.g., linolenic, eicosapentaenoic, docosapentaenoic, and docosahexaenoic acids) are obtained by the inclusion of flax seed, canola seed, fish oils, some species of micro- algae, or other ingredients containing h igh levels of these fatty acids. [9] Eggs enriched in this manner typically contain 400 to 500 mg of f atty acids of omega-3 series. Recent research has demonstrated that eggs c a n be enriched in other lipid-soluble factors such as lutein, beta-carotene, lycopene, conjugated linoleic acid, and oleic acid. [9,10] Eggs contain 12 of the 13 vitamins that are required by man: they lack only vitamin C (ascorbic acid). Chickens, like most birds and mammals, can synthesize this vitamin from glucose, and therefore it is not necessary for it to be present in the egg for the development of the chick. The fat-sol uble vitamins (A, D, E, and K) are present only in yolk where they associate with the lipoproteins of yolk. The remaining vitamins and 12 important minerals are present in both yolk and albumen, [7,8] although not necessarily equally distributed among both egg compartments. The US Department of Agriculture [8] reports the composition of whole egg, yolk, and albumen based on a running average of values submitted to their database. Currently, the vitamin content of whole eggs is as follows (in mg per egg): folate: 0.024, niacin: 0.035, pantothenic acid: 0.719, riboflavin: 0.239, thia- mine: 0.035, vitamin B 6 : 0.071, vitamin B 12 : 0.00065, vitamin E (alpha-tocopherol): 0.97, and vitamin K: 0.0003, and (in IU per egg) vitamin A: 487, and vitamin D: 34.5. The mineral content (in mg per egg) is: calcium: 26, copper: 0.051, iron: 0.92, magnesium: 6, manganese: 0.019, phosphorus: 96, potassium: 67, selenium: 0.0158, sodium: 70, and zinc: 0.56. According to Naber, [7] the biotin, inositol, and choline contents Table 2 Proximate analysis and energy content of the egg a Amount per egg Component Egg white Egg yolk Whole egg Water (g) 28.9 8.89 37.92 Protein (g) 3.6 2.7 6.29 Lipid (g) 0.06 4.51 4.97 Carbohydrate (g) 0.24 0.61 0.39 Ash (g) 0.21 0.29 0.43 Energy (Kcal) 17 55 74 a An egg weighing approximately 57 g with 50 ml edible contents (33 g of egg white and 17 g of yolk). (From Ref. [8] .) Eggs: Composition and Structure 3 Ap 913 of whole egg are 0.0097, 8.19, and 437 mg per egg, respectively. The chloride content is approximately 91 mg per egg. CONCLUSIONS The egg is composed of structures that serve to protect and nourish the developing embryo. It is a source of all of the essential nutrients except vitamin C. Recent research has demonstrated that the egg can be enriched in several nutrients by altering the composition of the diet of the laying hen. REFERENCES 1. U.S. Department of Agriculture (USDA). Egg Grading Manual; Agriculture Handbook No. 75; Consumer and Marketing Service: Washington, DC, 1969. 2. Shenstone, F.S. The gross composition, chemistry, and physicochemical basis of organization of the yolk and white. In Egg Quality: A Study of the Hen’s Egg; Carter, T.C., Ed.; Oliver and Boyd: Edinburgh, 1968; 26 58. 3. Marion, W.W.; Nordskog, A.W.; Tolman, H.S.; Forsythe, R.H. Egg composition as influenced by breeding, egg size, ag e and season. Poultry Sci. 1964, 43, 255 264. 4. Burley, R.W.; Vadehra, D.V. The Avian Egg; John Wiley & Sons, Inc.: New York, 1989. 5. Scott, M.L.; Ascarelli, I.; Olson, G. Studies of egg yolk pigmentation. Poultry Sci. 1968, 47, 863 872. 6. Solomon, S.E. Egg and Eggshell Quality; Wolfe Publishing Limited: London, 1991. 7. Naber, E.C. The effect of nutrition on the composition of the egg. Poultry Sci. 1979, 58, 518 528. 8. U.S. Department of Agriculture, Agricultural Research Service. USDA National Nutrient Database fo r Standard Reference, Release 17; Nutrient Data Laboratory Home Page, 2004; http://www.nal.usda.gov/fnic/foodcomp (accessed May 2005). 9. Gonzalez-Esquerra , R.; Leeson, S. Alternatives for enrichment of eggs and chicken meat with omega-3 fatty acids. Can. J. Anim. Sci. 2001, 81, 295 305. 10. Surai, P.F.; Sparks, N.H.C. Designer eggs: from improvement of egg composition to functional food. Trends Fd. Sci. Tech. 2001, 12, 7 16. 4 Eggs: Composition and Structure Ap 914 [...]... Science and Technology (CAST) The Well-Being of Agricultural Animals, Task Force Report, Publication No 130; 1997; CAST; ISBN 1-8 8738 3-1 0-7 4 Salem, D.J., Rowan, A.N., Eds The State of Animals; Humane Society Press: Washington, D.C., 2001 5 USDA FASS United States Department of Agriculture National Agricultural Statistics, 2002 (http:==www.usda.gov=nass=aggraphs=fl typwk htm) 6 Craig, J.V Domestic Animal. .. oceans, and leakage of hydrate deposits for CH4, as well as bacterial reactions in soils and oceans, and atmospheric reactions as sources of N2O.[2] CONTRIBUTIONS OF ANIMALS AND THEIR PRODUCTION SYSTEMS During the production and processing of crops to feedstuffs, through animal digestion and metabolism, and during the handling and disposition of manure, a Encyclopedia of Animal Science DOI: 10.1081/E... Development: Peri-Implantation Embryo Fuller W Bazer Department of Animal Science and Center for Animal Biotechnology and Genomics, Texas A&M University, College Station, Texas, U.S.A Greg A Johnson Veterinary Integrative Biosciences and Center for Animal Biotechnology and Genomics, Texas A&M University, College Station, Texas, U.S.A Thomas E Spencer Department of Animal Science and Center for Animal Biotechnology... Growth and Development: Pre-Implantation Embryo Fuller W Bazer Department of Animal Science and Center for Animal Biotechnology and Genomics, Texas A&M University, Texas, U.S.A Greg A Johnson Veterinary Integrative Biosciences and Center for Animal Biotechnology and Genomics, Texas A&M University, Texas, U.S.A Thomas E Spencer Department of Animal Science and Center for Animal Biotechnology and Genomics,... inferiority of the performance of parents to the superiority or inferiority of the performance of offspring If a quantitative characteristic was entirely due to genetic merit with no residual or temporary environmental influences, then the regression of offspring performance on performance of a parent would be one-half, reflecting the fact that each parent contributes half the genes to its offspring This... the assessment of the merit of an animal changing over time To remind users of these assessments that they are predictions, the acronyms EPD (expected progeny difference) and PTA (predicted transmitting ability) are used The value of the genes of the parents would be predicted as twice the value observed in the offspring, reflecting the fact that offspring inherit a random sample of half of their parents’... charged that the lives of food animals are viewed by their owners as lacking inherent value and that they instead consider the animals as only ‘‘live Encyclopedia of Animal Science DOI: 10.1081/E EAS 120019595 Copyright # 2005 by Taylor & Francis All rights reserved Ap 915 stock.’’ But historically, farm animal owners have viewed animal life as having worth,[1,3] and the majority of the public believes... 2894 10 Stricklin, W.R Benefits and costs of animal agriculture In Proceedings of the Scientists Center for Animal Welfare Symposium on Science and Animals: Addressing Contemporary Issues; Guttman, H.N., Mench, J.A., Simmonds, R.C., Eds.; Scientists Center for Animal Welfare: Bethesda, MD, 1989; 87 92 Ap 918 Genetics: Population Dorian J Garrick Department of Animal Sciences, Colorado State University,... of a few genes, or mixed inheritance models including one or more major genes in addition to residual polygenic effects A comprehensive range of traits is important to animal scientists and producers Many traits such as weaning weight, which are continuous in nature, allows the observed performance of animals to be ordered or ranked The average and the standard deviation of Encyclopedia of Animal Science. .. at the two-cell stage of embryonic development, many growth factors are expressed that influence cellular proliferation and differentiation including transforming growth factor-a and -b, insulin-like growth factor-I and -II, fibroblast growth factor-7, epidermal growth factor, and insulin Protoncogenes and viral-like genes incorporated into the embryonic genome are also expressed and include c-mos that . certain B-vitamins (biotin-, thiamin-, and riboflavin-binding proteins), and binding iron (conalbumen). The gel structure of firm albumen stems from the presence of at least two glycoproteins,. Technology (CAST). The Well-Being of Agricultural Animals, Task Force Report, Publication No. 130; 1997; CAST; ISBN 1-8 8738 3-1 0-7 . 4. Salem, D.J., Rowan, A.N., Eds. The State of Animals; Humane Society. of the storage structure depends on the amount of material generated in a day, the number of days required for storage, runoff from the rainy season, capacity to hold runoff from a 25-yr, 24-hr

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