Building a North American Feed Information System (1995)

The availability of accurate information on the nutrient composition of feeds is essential for livestock producers so that they can formulate diets that result in healthier, more efficient animals and so that they can use environmentally conscious farming practices to produce high-quality animal commodities. The amount of grain (wheat, rice, corn, barley, sorghum, millet, rye, oats, and mixed grains) fed to livestock as a proportion of total grain consumption in the United States has decreased from 80 to 70 percent and on a worldwide basis has remained constant at 38 percent (Food and Agriculture Organization of the United Nations, 1991; U.S. Department of Agriculture, 1993). The reason for the decline in the percentage of total grain used for livestock feed reflects an increase in the efficiency of feed utilization, the improved quality of feeds, and a slight decline in livestock numbers in Europe and North America. Conversely, world livestock populations increased 18 percent from 1970 to 1990, and the world chicken population doubled to 10.4 billion during the same period (Food and Agriculture Organization of the United Nations, 1991; United Nations Environmental Programme, 1991). Coincident with the increase in the numbers and efficiency of food animals, worldwide meat production in 1993 was 163 million metric tons, up from 42 million metric tons in 1950 (Brown and Kane, 1994). Recognizing that more than one-half of the cost of animal production can be attributed to feed costs, producers rely on appropriately managed nutrient levels in animal diets to maximize animal productivity and economic efficiency.

Production of poultry, pork, beef, and mutton has climbed significantly throughout the world over the past 45 years (Food and Agriculture Organization of the United Nations, 1991; U.S. Department of Agriculture, 1993). More than 31 billion kilograms (68 billion pounds) of red meat (beef, pork, veal, lamb, and mutton) and poultry were produced in the United States in 1993 (U.S. Department of Agriculture, 1994). Consumption of livestock products including meat, milk, and eggs has also increased, especially in developed countries, and is a function of economic status. The annual consumption of red meat and poultry has increased from 30 billion kilograms (66 billion pounds) in 1992 to 30.5 billion kilograms or 94 kilograms per capita (67 billion pounds or 207 pounds per capita) in 1993 and is expected to increase to 32.7 billion kilograms (72 billion pounds) in 1995 (U.S. Department of Agriculture, Economic Research Service, 1994a). To continue the production surge expected with domestic consumer demands and improving economies in developing countries, the efficiency of production must increase (World Resources Institute, 1992). Increasing feed efficiency through nutrient management is one way to enhance livestock production. The following discussions illustrate some of the ways in which nutrient management can affect animal production. Many valid examples exist in all animal industries, but the discussion here is limited to descriptions depicting a diversified livestock product, milk, and an increasingly preferred animal meat, poultry.

In the dairy industry, it has become apparent that production of the three major milk components (fat, protein, and lactose) is dictated by specific substrates that must be furnished to the animal from various feed sources. Milk pricing plans are moving away from the traditional price per hundredweight with an adjustment for fat content toward a price based on individual milk components (Dado et al., 1994). Changes in milk pricing are a reflection of consumer preferences. Per capita consumption of whole milk and butter has decreased by approximately 50 percent over the last four decades, whereas between 1970 and 1992 the per capita consumption of low-fat milk increased 75 percent and the consumption of skim milk increased 25 percent (U.S. Department of Agriculture, 1994). Consequently, the value of fat has decreased from 50 to 25 percent of the total value of milk (National Milk Producers Federation, 1993). Attempts have been made to assess the feed costs associated with the production of milk components by using linear programming dependent on ingredient sources and substrate availability (Dado et al., 1994). The results indicate that dairy production feed costs cannot be based strictly on an energy basis and the profitability of production of individual milk components may not be directly related to the component

market value. Although diet manipulation on the basis of feed composition can alter milk components, enhancing the percentage of protein in some cases (Polan and Fisher, 1993; Van Horn et al., 1976; Wohlt et al., 1991), milk yield appears to be the primary factor affecting component yields. Milk pricing is based on milk and component yields, and milk yield is directly related to dietary management (Sutton, 1989; Thomas and Martin, 1988). Therefore, the dairy nutritionist is faced with the challenge of adapting to changes in milk component pricing plans by using specialized nutrient management plans developed with information on the nutritive value of feeds that could be provided by the proposed feed information system.

Poultry producers recognize the economic importance of bone and egg shell fragility. Three to 6 percent of losses in the poultry industry are due to skeletal deformities (Leach, 1992). Studies on the adequacy of minerals and vitamins in poultry diets have provided valuable information on not only the requirements of poultry for these nutrients but also the interactions of these nutrients in poultry. A poultry diet may be formulated so that it contains adequate levels of vitamin D and calcium, but without sufficient dietary vitamin C, hydroxylation of vitamin D₃ to its most active form, 1,25-dihydroxy vitamin D₃ would not occur. Related biological and physiological processes such as intestinal calcium-binding protein activity, bone mass, and bone breaking strength are also affected by inadequate levels of vitamin C (Volker and Weiser, 1993). This concept is extremely important in young growing chicks because they are not yet fully capable of synthesizing vitamin C. The ability of older laying hens to produce endogenous vitamin C also is reduced. Complications such as these, which involve unique physiological considerations and improper dietary management, can be avoided by using accurate feed analysis and nutrient information to ensure that diets are appropriately balanced. As a result, economic efficiency increases with proper nutrient management. The cost of routine vitamin and mineral analyses is often prohibitive, however, making a data base that includes that type of information especially meaningful.

Another serious concern of broiler and livestock producers is the presence of biogenic amines in feeds. Biogenic amines are found in most common animal protein supplements and are associated with decreased animal performance. Correlations between high levels of biogenic amines and decreased efficiency of feed utilization have been reported in poultry (Keirs and Bennett, 1993). Necrosis of distal duodenal epithelial cells occurs when high levels of biogenic amines are consumed, resulting in poor feed utilization. These bioamines, which are often derived by bacterial decarboxylation of amino acids, are directly associated with poor feed efficiency in poultry and reduced livestock performance (Krizek, 1993). They have also been implicated in the intestinal maladies caused by

histamines experienced by humans after consumption of the Japanese raw fish delicacy sushi (Keirs and Bennett, 1993). Solutions to the problems experienced with certain protein supplements in poultry may hinge on the use of reliable feed analysis and nutrient information. Producers who use this information and who recognize the harmful effects of certain types of feeds can examine alternative feeds with similar nutrient composition.

An important property of feeds provided in a feed information system is dietary metabolizable energy. The effects of different levels of dietary metabolizable energy on productivity have been demonstrated in several species. Reducing dietary metabolizable energy from high to moderate levels in the last 2 weeks of a poultry finishing diet has the potential of reducing the amount of body fat of tom turkeys without adversely affecting performance or breast meat yields (Sell, 1993). This example of dietary manipulation of poultry diets on the basis of the nutritive value of feeds to produce the most desirable animal products demonstrates the dependence of such manipulations on the scientific use of analytical data, data that would be available from the proposed feed information system.

Efficient production and the well-being of the animal are direct functions of good animal health. Through integrated physiological mechanisms involving the endocrine, immune, and digestive systems, the animal responds to stimulatory effects and the demands of its environment to maintain a stable metabolic state (Elsasser, 1993; Turek et al., 1994). Nutrition plays a key role in many hormonal activities, eliciting responses from the immune system to direct nutrient traffic for tissue mobilization or catabolism, depending on the metabolic priority of the animal (Figure 2-1).

Nutrition is a large determinant of the endocrine response to stress (environmental or physiological) through regulation of plasma insulin-like growth factor and its response to growth hormone (Bass, 1990; Steele and Elsasser, 1989). Various dietary polyunsaturated fatty acids in grain oils also modulate the functions of porcine alveolar immune cells, which may prove to be significant for the host response to respiratory disease (Turek et al., 1994). Specific nutritional needs are therefore determined by coordinated regulation of the endocrine and immune responses to stress factors. By assessing the nutrient composition of feeds and supplying the appropriate complement of nutrients for endocrine and immune function, production losses can be limited, growth and productivity can be maximized, and animal health can be enhanced.

FIGURE 2-1 Regulatory input from the endocrine-immune gradient. GH, growth hormone; ACTH, adrenocorticotropic hormone; IGF-I, insulin-like growth factor I; ⇒ , inhibitory; → , stimulatory; (+/−), variable. Source: Elsasser, T. 1993. Endocrine-immune Interactions that Impact on Animal Health and Productivity. Pp. 81 –88 in Proceedings of the Maryland Nutrition Conference for Feed Manufacturers. College Park, Md.: University of Maryland Press.

Adequate nutrition is vital for the development and maintenance of the central nervous system. Malnutrition has been implicated in reduced brain capacity. Prenatal and postnatal malnutrition results in a 60 percent reduction in brain size (Winick, 1976), and disproportionate brain growth occurs when malnutrition is experienced at different stages of gestation (Morgan and Winick, 1985). Behaviors associated with undernutrition in animals include increased excitability, decreased exploratory interest, and slow extinction of a conditioned response (Brasel, 1974). Malnutrition and undernutrition and the likelihood of subsequent detrimental effects can be lessened if information on the nutrient content of feeds is combined with the nutrient requirements of animals, which are already known.

Suitable feeds can be identified and used to meet the animal's nutrient requirements during the different stages of its life.

Specific nutrients such as vitamin E, vitamin A, β-carotene, and selenium in animal diets have been associated with a reduced incidence of infection, enhanced reproductive performance, and improved immunocompetence (Babinsky et al., 1991; Gerloff, 1992; Hidiroglou et al., 1987, 1992; Lessard et al., 1991; Mahan, 1991; Reddy et al., 1986). Animal defense mechanisms against disease appear to be enhanced by increased intakes of vitamin E via an increase in ubiquinone synthesis (Lessard et al., 1991). Ubiquinone is a compound that increases phagocytic activity in the reticuloendothelial system (Heinzerling et al., 1974). The vitamin E content of feeds depends not only on the class of feed but also on the vegetative stage as well as on the methods of harvesting, storage, and processing. Differences in the vitamin E content of commonly used feedstuffs can be significant. For example, the total tocopherol (vitamin E) content of oats is reported to be 16.8 mg/kg, whereas the tocopherol content of soybean meal is 3.4 mg/kg on a dry matter basis (National Research Council, 1989b). Because the stability of natural vitamin E (tocopherols and tocotrienols) in feeds depends on moisture content, processing, storage conditions, and microbial activity, this nutrient is relatively unstable and is therefore a major concern in animal feeding programs. The more stable vitamin form, vitamin E acetate (dl-α-tocopherol acetate), is often used in compound feeds and premixes to compensate for vitamin E levels in feeds; however, this practice can be costly and may increase the risk of toxicity.

Vitamin E and selenium provide a mechanism of host defense against mastitis in dairy cattle by promoting the rapid intracellular killing of bacteria by neutrophils (Hogan et al., 1993; Weiss et al., 1990). Mastitis is a major concern for the dairy industry because it affects the health and productivity of dairy cows, costing the industry approximately $2.0 billion annually (National Mastitis Council, 1987). The incidence of mammary gland infections measured by somatic cell counts is decreased by almost 70 percent with dietary supplementation of vitamin E and selenium (Smith et al., 1987).

The interrelationship of dietary selenium and vitamin E is an important consideration in formulating animal diets. The influence of dietary vitamin E on selenium-deficient chicks indicates that protection against nutritional pancreatic atrophy relies on the antioxidative actions of vitamin E (Whitacre et al., 1987).

Variability of the vitamin E content in feeds, the poor stability of vitamin E, complex nutrient interrelationships, and management practices resulting in stressed animals are primary factors eliciting the need for timely and accurate analysis of the nutrients in feeds. Estimated vitamin E requirements may need to

be redefined as new information about the role that it plays in growth, health, and metabolism becomes available (Hidiroglou et al., 1992). With the advent in recent years of improved technologies for analyzing feeds for their vitamin E and selenium content, the levels of these nutrients measured in feed could be more accessible to producers, resulting in more efficient supplementation. Considering the cost restrictions associated with analysis, a data base that includes the vitamin E and selenium content of feeds affords the producer or nutritionist the ability to make reasonable determinations of the appropriate supplementation required to improve animal health and productivity.

Macronutrient manipulation in animal diets also can alter the incidence of disease. Lowering the protein content of the turkey diet during the first 4 weeks of life reduces by more than 50 percent mortality due to spontaneous cardiomyopathy (Breeding et al., 1994). Meat meal may play a role in inducing pulmonary hypertension syndrome in chickens (Julian et al., 1992). The source or derivation of macronutrients can affect defense mechanisms, growth, and feed utilization. For example, the rainbow trout (Oncorhynchus mykiss) exhibits increased leukocyte and plasma immunoglobulin levels, impaired growth, and abnormal intestinal morphology when it is fed soybean meal rather than fish meal (Rumsey et al., 1994). Comparison of the macronutrient concentrations of different feeds could easily be made with a North American feed information system, which would facilitate the formulation of diets appropriate for given species.

The global atmosphere is changing as a result of increasing worldwide emissions of the gases carbon dioxide, methane, chlorofluorocarbons, and other pollutants, all of which contribute to the so-called greenhouse effect. Unlike many environmental problems that may cause long-term damage, the detrimental effects of atmospheric changes are irreversible and directly affect the processes that support life. The depletion of ozone and alterations in temperature, precipitation, and soil moisture are only a few of the destructive alterations whose origins are largely attributable to human activities. Annual increases in primary greenhouse gas levels ranging from 0.25 to 4 percent with atmospheric lifetimes of 10 to 200 years suggest that drastic action is necessary to prevent further damage (World Meteorological Organization, 1993). Rapid responses to global warming and environmental pollution are important because a delay would only increase the risk of more severe pollution and call for more extreme reduction measures in the future. In addition to its detrimental effects on the environment, the resulting financial costs of pollution also must be considered.

Often, agriculture, and specifically, food animal production, is targeted as a major contributor to global warming. Animal species are, however, a vital part of the vast web of life, which functions as an integrated whole and which provides

humans with the food and fiber required for existence (Moore, 1987). All living organisms, including humans, are components of the same cycles of matter and energy. On the basis of this reality, it would not be reasonable, nor would it be possible, to completely eliminate production animals. Rather, efforts must be focused on better management of these animals. With the availability of a North American feed information system that provides accurate information on the nutritive values of feeds, nutrient management of animal diets becomes a viable avenue for an appropriate response to global warming and alterations of the environment.

Methane emissions from wild and domestic animals are estimated to be between 15 and 20 percent of the total global methane released annually (Bolle, 1986; Khalil and Rasmussen, 1990; Seiler, 1984; Sheppard et al., 1982) (Figure 2-2). Most of this methane is produced by cattle and domestic ruminants, with only 2 percent being emitted by wild ruminants. Methane production by animals has long been considered an inefficient use of dietary energy. Estimates of methane production are on average 6 percent of the animal's total dietary gross energy intake (Johnson, 1992) and range from approximately 3 to 4 percent for grain-fed cattle (Abo Omar et al., 1989; Blaxter and Wainman, 1961) to 12 percent for forage-fed animals (Blaxter and Clapperton, 1965). Quantitatively, those estimates represent approximately 300 liters of methane per day for an average steer. Certainly, the type of diet and the composition of the feed consumed substantially affect the amount of methane produced. Additionally, the use of hormone supplements and ionophores can alter and often improve the efficiency with which the feed is utilized, which in turn affects methane production (Rumpler et al., 1986). The use of bovine somatotropin in dairy cattle reduces the output of methane in individual animals by 9 percent (Johnson et al., 1992) and influences the rates of glucose and fatty acid metabolism (Bauman et al., 1988). Significant decreases in methane production are observed when monensin is added to the diets of growing-finishing feedlot steers (Zinn and Borques, 1993). Monensin and aibellin, an icosapeptide, markedly modify bacterial fermentation patterns in the rumen, reducing methanogenesis in vitro (Hino et al., 1993). Consequently, feeding programs incorporating detailed feed composition information will result in improved efficiency (less feed energy wasted), lower feed costs, and will maximize the benefits of using metabolic modifiers.

Development of new techniques to measure losses of energy from gas production in animals will allow more accurate estimations of the digestibilities and metabolizable energy contents of feeds and has great potential for reducing the amount of methane produced by livestock. Minimization of methane production may prove to be an important benefit from an environmental standpoint, but more practically, it is a sound nutritional management practice that will reduce the amount of feed energy wasted. Moreover, better prediction equations can be generated with feed composition information to more accurately reflect methane loss as it relates to diet and assessing the impact of methane on the environment.

FIGURE 2-2 Origins of annual global methane releases. Sources: Bolle, H. T. 1986. The Greenhouse Effect, Climate Change and Ecosystems, B. Boun, B. R. Doos, J. Jager, and R. A. Warmick, eds. New York: Wiley; Khalil, M. A. K., and R. A. Rasmussen. 1990. Patterns of trace gases near sources of global pollution. J. Air Waste Manag. Assoc. 40:1143–1146; Seiler, W. 1984. Current Perspectives in Microbial Ecology. Washington, D.C.: American Society for Microbiology; Sheppard, J. C., H. Westberg, J. F. Hopper, K. Ganesan, and P. Zimmerman. 1982. Inventory of global methane sources and their production rates. J. Geophys. Res. 87:1305–1312.

Nutrient loading, the runoff of excess nutrients into the soil and, subsequently, groundwater and surface water, is one of the primary concerns regarding agriculture's impact on the environment. Nitrogen and phosphorus are the primary environmental pollutants excreted in animal wastes (Roland and Gordon, 1993). Livestock and poultry in the United States excrete approximately 563 million metric tons of manure (wet weight), which contains about 5.89 million metric tons of nitrogen and 1.8 million metric tons of phosphorus (Cromwell, 1994). The U.S. Environmental Protection Agency (EPA) has identified agriculture as the single largest nonpoint source of surface water pollution (National Research Council, 1989b). Excretion of nitrogen, phosphorus, copper, and other minerals by agricultural animals poses a serious risk for groundwater and soil contamination with these elements (U.S. Environmental Protection Agency, 1992) (Figure 2-3). Groundwater accounts for 50 percent of the nation's drinking water, and in rural areas more than 95 percent of the population relies on groundwater for its water supply (Chesapeake Bay Program, 1992).

FIGURE 2-3 Sources of pollution in U.S. rivers. Source: U.S. Environmental Protection Agency. 1992. National Water Quality Inventory: 1990 Report to Congress. Washington, D.C.: U.S. Environmental Protection Agency.

Concentration of livestock production in large confinement feeding operations, or regional concentrations of dairy, poultry, or other animal production systems, has resulted in net nutrient loading in many areas throughout North America. Nutrient loading is of great concern in watershed areas, where entire regions drain ultimately into a particular watercourse or body of water. The Chesapeake Bay region is one of many such watershed areas; Maryland, Pennsylvania, and Virginia are all part of this watershed area, and all three states have intensified agricultural industries.

Substantial environmental and economic benefits would be provided to the Chesapeake Bay Decision Support System (CBDSS) by a North American feed information system, in that current data on feed composition would be continually accessible to CBDSS and this information would be an integral component not only for assessing the impact of land use but also as a prophylactic mechanism for reducing nutrient loading. Recognizing the value of an integrated data base system, CBDSS is being developed to provide a means of exchanging information with many other regions and localities facing the same environmental challenges. CBDSS could be improved for use throughout the nation if it incorporated information on the nutritive properties of feeds; and efforts to address the contribution of animal nutrient excretion to environmental pollution would be greatly facilitated.

A cow produces approximately 80 percent as much gas (carbon dioxide and methane) annually as an automobile (Pell, 1992); however, the gas is produced from newly generated biomass and may not contribute to the net rise in atmospheric carbon dioxide levels. The coproducts of the breakdown of urea are ammonia and carbon dioxide. Although the production of carbon dioxide by animals may not be directly responsible for increasing levels of this gas in the atmosphere, the ammonia produced by ruminants contributes to acid rain. More than 20 percent of the acid rain in the Netherlands is suggested to be attributable to animal agriculture (de Lange, 1994). The cost associated with this acid rain is estimated to be $500 million per year as a result of reduced crop yields and excessive deterioration of buildings. Reducing the amount of ammonia emitted by animals is possible through dietary management. This can be done by changing the components of animals' diets on the basis of information on the nutrient composition of feeds. Such changes involve modification of protein levels and amino acid composition or synchronization of the use of components like protein undegradable by the rumen and carbohydrates to maximize microbial efficiency, allowing the producers to optimize protein utilization by the particular animal species and thus minimizing ammonia (and nitrogen) excretion (DePeters and Cant, 1992; Waldo and Glenn, 1984). Reductions in the levels of excreted nitrogen can be significant only by changing the level of protein in the diet. The amount of nitrogen excreted by a dairy cow can vary by 10 percent with only a 1.5 percent change (dry matter basis) in the crude protein level in the animal's diet (Van Horn, 1991). When the level of crude protein in the dairy cow diet is increased from 16 to 20 percent, increases in the amount of nitrogen excreted in the urine can be as much as 50 percent (Andrew et al., 1991).

Frequently, animals are fed excess protein, usually because the exact amino acid composition of the feed is not known. Nitrogen loss is affected by feeding levels. It is estimated that pigs fed at 8 percent of their metabolic live weight

excrete 31.4 g of nitrogen per day, whereas pigs fed at 14 percent of their metabolic live weight excrete 58.7 g of nitrogen per day (Moughan, 1991). Because non-ruminants require specific amino acids rather than protein per se, it is important to know the amino acid composition of feeds. Data on the amino acid composition of feeds have been relatively scarce (National Research Council, 1982), but the technology for analysis of feeds for their amino acid content has progressed in recent years, increasing the number of feeds for which this information is available (Llames and Fontaine, 1994). The amino acid content of many feeds could be provided through a North American feed information system. Producers and their consultants could use the information to better balance the amino acid content of animal diets and reduce the amount of nitrogen excreted.

Ruminants do not have specific dietary amino acid requirements because of amino acid synthesis in the rumen (National Research Council, 1985). The quantity and quality of the protein produced by rumen microbes, however, may be inadequate for animals at high levels of milk production and can be affected by dietary factors (Nocek and Russell, 1988). Feeding ruminants high-quality protein that escapes the rumen enhances milk production (Waldo and Glenn, 1984). Thus, feeding an optimal combination of protein sources may allow livestock producers to lower the level of protein in the diets of ruminants, resulting in lower levels of nitrogen excretion.

Much of the phosphorus in the diets of nonruminants such as swine and poultry is biologically unavailable; therefore, much of this nutrient is excreted. Approximately 60 to 75 percent of the phosphorus in cereal grains, grain by-products, and oilseed meals occurs as an organic complex, phytate, which is not readily digested by swine and poultry (National Research Council, 1984, 1988) because they lack the digestive enzyme phytase. Historically, it was assumed that only one-third of the phosphorus in feedstuffs of plant origin was available for utilization in nonruminant species. Consequently, excess levels of phosphorus have been fed to swine and poultry, resulting in significant levels of phosphorus excretion into the environment. A review of the research suggests that there are major differences in the bioavailability of phosphorus among feeds (Cromwell and Coffey, 1993). Additionally, research in the Netherlands (Jongbloed and Lenis, 1992) and the United States (Cromwell et al., 1991, 1993; Lei et al., 1991) indicates that utilization of phosphorus from corn and soybean meal may be improved two- to threefold with the addition of the enzyme phytase to the diet. With improved technologies to measure the bioavailabilities of nutrients such as phosphorus and the use of feed additives like phytase, balancing dietary nutrients takes on a more diverse and often complicated role requiring accurate information of the nutrient composition of feeds to make best use of new information.

Agriculture has long been a leader in the recycling effort. Making use of industrial wastes, forest and crop residues, animal wastes, and aquatic plant material, the livestock industry has helped to solve the problems related to disposing of these materials while incorporating them into productive alternatives. Often, out of necessity, producers have turned to less costly forms of animal feeds, recycling by-products and wastes. For instance, more than 1 billion kilograms (2 billion pounds) of restaurant grease waste is used in animal feeds annually (Rouse, 1994). Recycling its own waste, the animal industry incorporates approximately 16 billion kilograms (36 billion pounds) of animal by-products inedible by humans into animal feeds each year. Analysis of the nutrient values of nontraditional feeds such as by-products or uncommon or underused substances is necessary to further promote their use (National Research Council, 1983).

Brewer's grains from the beer brewing industry may be the best example of recycled waste products. In fact, large cattle operations have traditionally been located within 200 miles of a major brewery. Dairy producers have found that use of wet brewer's grains in the diets of dairy cows increases milk yields and that feeding costs are generally lower.

Waste products such as animal manure and feather meal, vegetable wastes, and fish mortalities from fish farms have been evaluated and suggested to have great potential in animal feeding programs (El-Boushy et al., 1990; Flachowsky and Hennig, 1990; Fontenot, 1991; Gao et al., 1992; Gupta et al., 1993; Pilbeam, 1980). Because of the intense production capability and rapid growth of aquatic plants, seaweeds and algae appear to have value as animal feeds and may have an effect on meat, enhancing its color quality (National Research Council, 1983; Venkataraman et al., 1994). Alternative aquatic plant feeds can prove to be economically beneficial, replacing more expensive feeds such as fish meal that have similar nutrient composition. Underused feeds such as crop residues have striking potential for use in animal production. Because of the enormous quantities of wastes such as crop residues produced annually, agriculture will benefit from their increased use. Integrating wastes into existing feeding programs cannot be accomplished successfully without accurate information on the nutritive value of such wastes.

Factors such as availability, alternative uses, ease of use, and relative safety for animals and humans affect the extent to which underutilized feeds can be used (National Research Council, 1983). Most important, the nutritional value of underutilized feed material relative to cost will determine its use as an animal feed. Although some information on by-products and recyclable feed materials is available, a North American feed information system will expand the appropriate use of these items domestically and on a global level.

Constructive nutrient management allows producers to control the levels of nutrients excreted by animals into the surrounding environment (Van Horn et al., 1994). The nutrients of feeds and forages can be manipulated to enhance animal production. Correlating with improved animal feeding, the health and welfare of the animals are enriched, and thus, productivity and profitability are increased. These aspects of nutrient management make it a sustainable agriculture practice.

Feeding animals to minimize the excretion of nutrients considered to be environmental pollutants, such as nitrogen, phosphorus, ammonia, and methane, is a logical starting point for integrating plant and animal systems while enhancing the natural resource base of agriculture. Traditionally, some nutrients have been overfed on the basis of bioavailability estimates, resulting in fecal excretion of excess nutrients into the environment. The result is nutrients leaching from the soil or preferential accelerated eutrophication when water runoff or soil erosion occurs, contaminating water sources. Use of nutrient composition information to make informed decisions on precisely balanced animal diets will minimize contamination of the environment from excess nutrient excretion, and financial benefits can be realized. Commitment to sustainable agriculture includes the intelligent use of technology in a way that is both productive and environmentally conscious. A North American feed information system would allow new information and technology to be used in a way that ultimately benefits the environment as well as the producer and consumer.

Additionally, alternative farming strategies that incorporate natural processes such as nutrient cycling and nitrogen fixation reduce the use of manufactured products that may harm the environment (National Research Council, 1993). As a result, well-managed alternative farming systems may use less synthetic chemicals and antibiotics per unit of production than comparable conventional farms. Consequently, the adverse effects of farming on the environment are reduced. Pressed with manipulation of natural plant processes to enhance the use of crop nutrients and the nutritive value to animals, the farmer is obliged to rely heavily on detailed data on the nutrient composition of crops and feeds.

Genetic engineering has been one of the important scientific advancements of the twentieth century that affects agricultural management issues (National Research Council, 1993). The development of more efficient, disease- and insect-resistant, nutrient-dense, high-yielding, and, therefore, more environmentally sound strains of plants has enhanced the productivity and efficiency of agriculture. Biotechnological advances bring about alterations in the biological characteristics of plants, often including their nutritive properties. Barley, for example, has undergone genetic alterations that are reflected positively in its

nutrient characteristics (U.S. Department of Agriculture, Agricultural Research Service, 1991). It is important that these variations be identified and reported accurately in a North American feed information system to reflect the changes in nutrient content for use in animal production, as well as to reflect the economic value of these products in agricultural trade.

Complementing advances in genetic engineering and sustainable agriculture systems, and a key component in integrating these diverse agricultural sciences, is the use of information technologies that have a positive influence on agriculture's environmental impact. A North American feed information system could be an essential link uniting different areas of environmentally sound science and enhancing achievements in each area, whether in animal nutrition, bioengineering, sustainable agriculture, or agricultural education.

There is general agreement that some type of regulation needs to be in place to monitor nutrient concentrations and contaminants that may affect animal and public health. A major concern, however, is the point of reference on which regulatory decisions are based. The specific processes and analytical methodologies used to establish the tolerance concentration of a nutrient or contaminant may be on the basis of a single and often nonrepresentative number. A comprehensive feed data base must include a variety of conditions under which feed is processed or manufactured to yield a concentration range rather than a single concentration for a specific component. Making decisions based on more extensive data would add credibility and accuracy to the regulatory process.

In the United States, the safety of most food and feed ingredients is regulated by the Food and Drug Administration (FDA) under various provisions of the Food, Drug, and Cosmetic Act (Public Law 98-80). U.S. government policy extends existing laws to the regulation of food products, especially those modified by biotechnology. When regulatory agencies review new or modified feed ingredients to be used in livestock feed, they must have accurate data that they can use to evaluate the safety of those particular ingredients.

Present laws recognize that the natural food supply contains many substances that, when isolated and consumed in large amounts, may be toxic but that are neither toxic nor harmful when consumed as inherent constituents of feeds. However, mycotoxins, which are toxic metabolites of fungal contaminants of feed grains, can be harmful to animal and human health. Aflatoxin has traditionally been the major mycotoxin of concern to animal producers. More recently, fumonisin, vomitoxin, and others have increasingly become more prevalent and pose a risk to animal health (Marquardt and Frolich, 1992; Rotter et al., 1994;

Wood, 1992). Testing for mycotoxins either at the point of production or before incorporation into human food or animal feed is a vital step for maintaining feed safety. Rapid progress has recently been made in the area of analysis of mycotoxins in feedstuffs (Chu, 1992). More than 50 countries have enacted or proposed regulations for mycotoxins in foods and animal feed (van Egmond, 1993). Of particular importance in regulating mycotoxins is the availability of toxicological data, levels of dietary exposure, levels of mycotoxins in various commodities, the methods of mycotoxin analysis, and the legislation of other countries with which trade contracts exist (van Egmond, 1993). Only a few countries have formally presented the rationale for regulation, the selection of a particular tolerable level, or the development of standard reference materials (Petersen, 1994; van Egmond et al., 1994). Belgium, Canada, India, the Netherlands, Switzerland, South Africa, the United Kingdom, and the United States claim to have evaluated the hazards. On the basis of a recent international survey, regulation either was not based on scientific information or the science had not been fully used. A feed information system that includes scientific, accurate, well-documented information has the potential to provide a scientific basis for enhancing producers' and consumers' levels of comfort with the safety of feed ingredients. Alternatively, regulations based on assumptions or inaccurate data have the potential to create a serious trade barrier globally and within different regions.

To ensure the safety of primary and coproduct ingredients, especially those originating from biotechnological processes, a system for adequate evaluation needs to be developed. Specific ingredients, processed derivatives or coproducts of agricultural commodities, biological ingredients, processing aids, and chemical additives should be evaluated.

Tailoring regulatory standards and procedures to address food safety concerns is a critical issue and will demand even greater emphasis in the future. The use of a dynamic feed information system will help to ensure that food safety issues are evaluated fairly and justly from a scientific rather than an emotional perspective.

Assessment of the state of agriculture in other countries reveals that legislation is being developed and recommendations are being made to reduce agriculture's contribution to environmental pollution (Hacker and Du, 1993; Williams and Kelly, 1994). Proposed regulations and recommendations increase overall production costs, with the result being that the agricultural industry attempts to find ways to reduce the industry's effect on the environment through waste nutrient management (Magette et al., 1989). Countries such as Switzerland, South Africa, Japan, Germany, and the Netherlands have become active in addressing environmental concerns, and some have placed restrictions and bans

on the amounts of animal waste and detergent phosphates that can be applied to the land.

Federal programs in the United States such as the Conservation Reserve Program have been developed with provisions that strongly influence agricultural practices affecting water quality. USDA views water quality as a priority directing the efforts of agencies to support the water quality initiative. The Clean Water Act (Public Law 92-500) aids state endeavors to protect their groundwater and surface water resources by requiring control programs through regulatory and voluntary mechanisms, including effective farm nutrient management. Under the Clean Water Act, concentrated animal feeding operations are required to obtain a permit if they have more than a certain number of animals (Center for Rural Affairs, 1993). EPA issued a blanket permit covering all concentrated animal feeding operations in four states (Texas, Oklahoma, Louisiana, and New Mexico) that did not voluntarily obtain permits. The regulations require the facilities to follow best management practices in dealing with contaminated runoff, waste handling, isolating open lots and wastes from outside surface drainage, and prohibiting pesticide-contaminated waters from being discharged into surface waters. Additionally, each operation must develop a pollution prevention plan outlining how its wastes will be controlled. A North American feed information system consisting of accurate analyses of feeds will provide a scientific basis for the development of both food safety and environmental regulations.

INFIC, originally established in 1971 with 18 organizations, functions as a platform for contributing to sustainable, environmentally sound, efficient animal production and a safer world food supply. INFIC promotes the establishment of main regional centers and continental networks of feed information centers as part of its goal of providing opportunities for the international exchange of information and cooperative processing of data on the nutrient composition of feeds. Currently, 37 institutions (from approximately 20 countries) throughout the world are members of INFIC. The function of INFIC is to improve access to reliable information on the composition, nutritive values, and practical uses of feeds for animals. INFIC addresses problems related to the international coordination of feed data and communication and technical matters. Because institutional membership is restricted to countries that maintain an active national data base, the United States does not participate in the international exchange of scientifically generated feed composition data. In addition to INFIC, other feed information systems such as the European Network of Feed Information Centres and the Australian Feed Information Center have established mechanisms for information exchange. The United States could participate in these systems by establishing a center for the exchange of data if a North American feed information system were implemented. Technical and scientific contributions from the United States

to the worldwide efforts of INFIC are conspicuously absent. Notwithstanding the benefits of association with INFIC and other international systems, the United States has a responsibility—not only as a nation of advanced, proven scientific capability but also as a prominent member of the world's agricultural trade market and a leader in environmental conservation efforts—to encourage and take part in progressive international activities.

A report issued by USDA's Economic Research Service stated that “with the General Agreement on Tariffs and Trade (GATT) accord calling for reducing export subsidies, the importance of grain quality's role in enhancing U.S. market share will likely increase” (U.S. Department of Agriculture, Economic Research Service, 1994b). The report further explained that it was not quality but price that determines overall market share, but that the situation would likely reverse under GATT. As the quality-sensitive sector (countries placing emphasis on the purchase of high-quality grain) of the global grain market expands and with the implementation of GATT, the challenge for U.S. grain exporters is to compete effectively in the quality-conscious import markets.

U.S. exports of corn, soybeans, rice, and wheat are expected to increase over the course of the 1995 marketing year because of reductions in the exportable supplies from countries that are major competitors of the United States (U.S. Department of Agriculture, Economic Research Service, 1994a). The U.S. share of the wheat export market has increased to approximately 34 percent. With China's wheat imports doubling to ensure plentiful supplies, exports from the United States and Canada are expected to rise to 31 million metric tons in the next year. Additionally, corn exports from the United States are anticipated to increase 15 percent, which will result in the United States having 62.4 percent of the world market share.

Although world rice trade is expected to fall, U.S. rice exports will rise. Soybean exports from the United States are forecast to increase almost 14 percent, to 16.7 million metric tons, in 1995. In fact, the volume of oilseed trade could reach a record high in 1995. Although the worth of intermediate high-value commodity exports, such as animal feeds, soybean meal and soybean oil, and seeds, is not expected to increase in the near future, the United States continues to maintain a large part of the agricultural feed grain export market. On the basis of the significant portion of the export market held by the United States, current accurate nutrition information on feeds can become a major factor in determining the values of commodities. To guarantee an optimistic outlook for export sales, the United States must use feed composition information to influence sales on the basis of grain quality and to ensure compliance with feed nutrient specifications.

In light of rapidly growing U.S. oilseed and grain exports, accurate feed

composition analyses of export commodities take on an increasingly important role. Because the United States is a major force in world agricultural trade, the United States can attain a more competitive position by using information about the composition of export grains to write more detailed nutrient specifications and enhance commodity sales. The current grading system for feeds traded in world markets is not based on nutrient composition; however, some commodities, such as soybean meal, are bought and sold on the basis of nutrient specifications including moisture and protein content. Outdated and, for the most part, meaningless grain grading systems are used for the sale and purchase of these commodities. Considering the magnitude of variation in the nutrient composition of grains that can occur because of such factors as processing, environmental growing conditions, and disease, a single feeding value assigned to a particular feed will not always be reliable. Creation of a North American feed information system would (1) provide the relative nutritional values of feeds that are not provided to the purchaser in the current grading system and (2) may influence considerations in the current grading system to rely more on accurate data regarding the nutritive value of feeds for pricing rather than the currently enforced parameters of physical characteristics such as number of cracked seeds or foreign matter.

The U.S. and world agricultural commodities markets face continual change brought about by fluctuations in levels of production, domestic supplies, economic growth, and governmental influences. Producers in the United States are often faced with instances requiring access to instantaneous prevailing information on the nutrient composition of feeds. For instance, although U.S. wheat imports by China are expected to increase, imports of U.S. wheat by other major purchasers are expected to decline. The world price for wheat is high, creating a challenge in marketing this commodity. Substitution of alternative feeds on the basis of a comparison of quality and nutrient composition can bring better balance to the trade and use of many grain commodities. Additionally, livestock inventories in countries such as those of the former Soviet Union are decreasing, with a subsequent decrease in feed demand. The livestock industry in the United States and throughout the world has a direct effect on the trade of feed grains. Technological advances in the genetic engineering of plants require close monitoring of the compositional changes in grains that affect feed and its consequent market value. With the dissemination of nutrient composition information, the significant innovative improvements in barley that have occurred could be reflected in its value. The challenges brought about by continually changing circumstances in world agricultural trade can successfully be engineered and met with accurate feed analysis and thoughtful marketing strategies.

Accelerated growth in the global economy over the next decade has been projected on the basis of a variety of factors. The economies of developed countries are expected to surge, developing economies will continue to advance, and the economic status of the countries of the former Soviet Union and Eastern

Europe will improve. The implementation of GATT and the North American Free Trade Agreement (NAFTA) also plays a role in this (U.S. Department of Agriculture, 1994). Continued strong economic growth worldwide will bring about increasing demands for U.S. agricultural products and, hence, the need for timely accounting of the nutrient composition of feeds.

A long-term perspective of global change in commodity trade and use within regions, such as Europe and the Far East, will become more critical with changing regional production capabilities and the availability of different types of feeds. A decline in the ability of Atlantic fisheries to provide fish meal for the production of protein supplements may create a reliance on alternatives to fish meal. These include plant-based supplements that are priced and accepted on the basis of their quality. The size of the potential market could be substantial, with estimates ranging in excess of 100 million metric tons. North America would have the opportunity to fill this growing need, placing emphasis on the ability to provide accurate data on the quality of these commodities on the basis of their nutrient composition.

Long-term uses of information on the nutrient composition of feeds also include increased demand for animal products in developing countries and the future formation of larger trading blocs associated with development. Regulations on feedstuff quality and composition in the European Union, for example, may make the introduction of new feedstuffs more difficult unless high quality and accuracy can be ensured through reliable information exchange.

Strategic development and marketing of genetically improved feedstuffs, promotion of underused by-products and uncommon feed materials, and improved use of natural resources internationally are all possible through the dissemination of nutrient composition information. The value of feed products will be more accurately reflected if current information on nutrient composition is available. The ability to write detailed nutrient specifications is imperative to competing in the agricultural export market. Currently, the European Union has set several standards related to nutrient content for the importation of commodities that block a large portion of products from the U.S. market.

The United States would benefit from the ability to meet the different demands among countries. Some countries seek out certain types of feed grains with specific characteristics as a result of specialized food production (Heien, 1982). Often, those countries are willing to pay a premium for products that meet their requirements. Additionally, niche markets exist, and these drive the need for unique grain qualities. Thus, providing accurate, updated, detailed information on the nutrient properties of U.S. feed grain commodities will facilitate trade in quality-conscious markets. In general, an increase in the amount of information allows the agricultural trade market to work more productively (National

Research Council, 1990). A lack of information decreases efficiencies and tends to create instability and asymmetry within the market. The information on the nutrient composition of feeds provided by the United States may not increase the overall U.S. share of the world market, but it may increase the price of commodities on the basis of quality.

The feed information system will put the U.S. agricultural industry in a better position in international trade. Scientific advancements in the industry will be better reflected, and thus, profitability will be improved. Promotion of nontraditional feedstuffs is possible with a North American feed information system. All aspects of U.S. competitiveness in the marketing and trade of agricultural commodities will be improved.

World population projections are estimated as high as 12 billion people by the year 2150, up from 5.6 billion today (Bongaarts, 1994). Feeding the population and protecting the Earth simultaneously over the next 50 years will be difficult. Technologies to double food production with the same amount of land without destroying that land will have to be developed. The international scientific community can take a leadership role by exchanging feed composition data so that each country can focus and make informed investments to address the particular agricultural needs associated with feeding its population.

The manner in which information on the nutrient composition of feed is used is varied, depending on the country's economic status. Agricultural intensification in developing countries often includes severe exploitation of a country's natural resources simply for the survival of its population. Knowledge of the nutrient value of feeds that are imported into or cultivated within a developing country can improve the decision-making process on land utilization and commodity purchases and can improve the health and nutrition of the population.

Currently, more than 544 million metric tons of grain (33 percent of the total produced worldwide) is fed to animals. On a global level, the ratio of the output of usable products from animals to the input of parts of grains usable by humans is approximately 6:1 (McDowell, 1992), since a large part of the animals' diet is forage. Thus, to increase the efficiency of food production for humans, use of feeds (grain) for animal production is essential, although the advantages are not always readily appreciated by the general public. The science of feeding animals therefore becomes a challenge of maximizing returns without creating detrimental consequences. The goal for many producers and farmers is carefully managed animal agriculture that may ultimately improve the environment. To address this objective, reliance on information on the nutrient composition of feed as a management tool for animal feeding has become essential.