A number of animal species have benefited from the nutritional and functional benefits of animal by-product ingredients. However, the species providing the staple market for animal protein meals have been poultry, companion animals, swine, cattle, and an evolving market in aquaculture. Though research has demonstrated the rumen degradable protein and amino acid properties as “bypass protein sources” derived from animal protein meals by the ruminant animal, their use has diminished from those diets. Certainly all non-ruminant meals, to include porcine meat and bone meal (MBM), can still be used effectively in ruminant diets. But bovine spongiform encephalopathy (BSE) issues, real or perceived, have somewhat limited usage to feather meal and blood meal in ruminant rations. The Food and Drug Administration feed ban rule of 1997 is very effective as well as specific. It specifies that ruminant-derived tissue, with specific exemptions, cannot be fed to ruminants. The exemptions include porcine-derived MBM, blood meal, and tallow. But the marketplace has virtually eliminated all MBM from their formulation matrixes. It has been necessary to enhance the exploration of new uses and pursue the feed ingredient market for other species with greater emphasis – a historical factor that has persisted as a constant challenge that has required the industry to adapt and change. It has done so very effectively.
Poultry
The poultry industry currently utilizes approximately 35 to 45 percent of all rendered animal by-products, making it the overall largest user. Perhaps it is also the reason it is the most efficient producer of animal food protein, poultry meat, and eggs. Poultry can effectively utilize all animal protein meals, as all have been used successfully at various levels in the rations of poultry of all types. Higher usage levels are used in broilers and turkeys due to their relative protein needs in comparison with egg production birds. Feed manufacturing facilities for poultry diets are predominately dedicated species mills so that any possibility of cross-contamination into ruminant rations is not a major concern. Nutrient composition values of animal protein ingredients are more clearly defined for poultry species. Much of the basic protein and amino acid and true metabolizable energy database values have been developed using the precision-fed cecectomized cockeral assay. The database continues to be refined and expanded via various industry consortiums and improved analytical technology. The Fats and Proteins Research Foundation (FPRF) is co-sponsoring a “Digestibility of Amino Acids Derived from Meat and Bone Meal Sources for Broilers” study with Dr. Todd Applegate, Purdue University, as project leader. A university consortium comprising of the University of Illinois, Ohio State University, University of Kentucky, and Michigan State University, in addition to Purdue and other industry cooperators, are involved in the project now entering into its second year. The study is attempting to develop more rapid and accurate analyses for predicting nutritional values as well as comparing experimental procedures for their validation.
Current formulation practices are demanding that more exact nutrition composition values are available. Formulation models using either the cecectomized cockeral or ileal digestible amino acid levels, while maintaining established ideal protein ratios, are very standard. Ideal protein ratios establish amino acid levels in the formula based on specific ratios to one given amino acid, usually lysine. In broiler diets, the trend towards higher density amino acid diets is becoming more common. A digestible lysine level of 1.38 percent in high-density diets would require 0.93 percent methionine (Met) plus cystine (Cys) to maintain a 1:674 lysine to Met + Cys ratio. In comparison, a diet containing a more moderate level of lysine at 1.28 percent would require 0.87 percent of Met + Cys to maintain the same ratio. This procedure is established for each of the essential amino acids. Dr. Jeffre Firman provided a basic outline of ideal protein/precision feeding and best-cost nutrition in the August 2004 Render.
However, in order to accomplish this precision, research must provide the amino acid requirements and analytical technology must provide an economical and accurate method to determine the nutrient components provided by the feed ingredients. These advances are meticulous and research demanding, but the poultry industry has persistently and dramatically improved growth rates, feed conversion, and overall efficiency of meat production via their persistence in precision feeding.
Animal-derived feed ingredients have and continue to provide important contributions to poultry production. While historically there have been some limits on the use of animal products in poultry rations, most of these limits have been artificially set due to lack of information. The rendering industry and its suppliers have developed databases that reflect a more modern assessment of digestible amino acids and metabolizable energy values for their products. This will become even more important as formulation matrixes and animal requirements are further refined. Research will dictate the progress.
Companion Animals
The pet food industry is a major business in the United States with an estimated 54 million dogs and 60 million cats in homes of pet owners. The growth has not been exclusive to the United States and is evident throughout the world. An estimate of global pet food sales in 2002 exceeded $32 billion and the market has continued to expand. Animal by-products have been a major staple in these diets, which has utilized 25 to 30 percent of all animal by-products. In the past, the pet food industry has utilized up to 25 percent of the U.S. MBM production. It is a market that the industry must culture, but it is also a market that has changed dramatically in the past decade, not only the expansion in its total volume but its demographics as well.
Pet food is acquiring the same status as human food and is purchased using the same purchasing decisions as the family’s weekly groceries. There is a rise in the interest in feeding for animal well-being, longevity, and preventative medicine. Even the vegetarian myths are influencing the formulation and product labeling. Meat and bone meal, once a staple animal protein in most pet food formulas, has developed a connotation of being a livestock feed ingredient. It will take an education process to alter the trend. Today, chicken, turkey, and fish meal appear to have more label appeal than beef or pork.
Currently the global dog and cat food market is concentrated among six major players. Two companies hold a combined market share of nearly 70 percent. Many are international and part of large conglomerate multiple-industry organizations. Nearly all pet food manufacturers possess research facilities or contract for proprietary research. Marketing programs are almost universally driven via new products and veterinary endorsement.
In addition to placing importance on label descriptions of ingredients, the ingredient specifications can become major issues. Digestibility of protein and amino acids are probably of less importance to companion animal formulation than in food production animals. However, digestibility is correlated to fecal volume and consistency and is an important criteria. Animal by-products have been valued for these properties when compared to plant derived proteins. Ash content is an important criteria in pet food formulations and MBM continues to be criticized for excessive ash content. The issue of ash level has resulted in various designations for poultry meal or poultry by-product meal. “Feed-grade” poultry meal is seldom used in pet food due to its higher level of ash. Ash levels of 11 to 15 percent are preferred by the pet food industry with the lower levels used in cat food diets.
Animal-derived proteins are uniquely positioned to serve the pet food ingredient market. Its industry has focused on safe feed/safe food principles. Dogs and cats by nature are carnivorous. As an illustration of this trait, studies have demonstrated that olfactory acuity in English pointers was affected by the origin of the fat. Olfactory scores were higher when dogs were fed beef tallow compared to plant oil sources. This, coupled with elevated nutrient density and animal-based proteins, led to better performance in the field. Studies have also demonstrated that cats favor diets with animal-based fat over diets with vegetable-based fat. As with human nutrition, obesity in the companion animal population and health issues are of high priority in pet food formulations. The pet food industry has changed as has the rendering industry and its products. To maintain its position in the companion animal feed market, the rendering industry must continue to “reorder its priorities.”
Swine
The use of animal by-products in swine rations has fluctuated greatly over the years. Tankage, MBM, and meat meal were the primary supplemental protein to swine rations until soybean meal and synthesized nutrients emerged as readily available ingredients. The era of corn/soy-based swine rations, due in part to the simplicity of on-farm blending of home raised or local corn, commodity soybean meal, and a convenient package of vitamin/minerals became the norm for the smaller unit swine farms. As a result, the familiarity with animal by-product ingredients for swine waned. Currently, the swine industry is projected to use approximately 13 to 15 percent of the U.S. production of MBM. Its usage in this market segment is increasing but needs further promotion in both the domestic and international markets. The concentration of swine production and central feed manufacturing practices that more efficiently control quality, while providing the benefits of storing and utilizing multiple ingredients for best cost computer formulation, allow the modern production systems to maximize both the performance and economical benefits of animal protein ingredients. The feed formulation practices followed on most swine units today do not differ significantly from those described for poultry. Meat and bone meal and meat meal both of ruminant or porcine origin are excellent sources of amino acids, energy, and minerals for swine. Modern production practices as well as changes in the feed ingredient markets and formulation technology all account for reasons that MBM and other animal proteins be included in today’s swine diets.
Research is continuing to bring data to modernize the nutrient composition tables especially for amino acid digestibility and metabolizable energy values. Dr. Layi Adeola and his colleagues at Purdue University have published data and are currently pursuing further studies to demonstrate that a number of databases underestimate the metabolizable energy of MBM. The swine industry is a major generator of animal by-product material and a major and potential greater user of animal by-product ingredients. Research and the transfer of the results are important to both the swine and rendering industries. The February and April 2004 issues of Render contain additional reference information for utilizing animal by-product protein and fat in modern swine diets.
Aquaculture
Current headlines continue to recite the news of the increase in U.S. per capita consumption of seafood. In the latest U.S. Department of Agriculture report, seafood consumption hit an all-time high in 2003 and the consumer demand continues to increase. Aquaculture in particular is a prime contributor to this demand. However, when compared to other major protein sources in the American diet, seafood is still well behind. Shrimp leads the U.S. per capita seafood consumption at four pounds per year. Canned tuna, salmon, pollock, catfish, cod, crab, tilapia, clams, and scallops, in that order, contribute to the approximate 15 pounds per person annual U.S. consumption. Though the top three most popular seafood choices in America are farm-raised products, the domestic feed ingredient market for these species is somewhat limited, except for perhaps salmon. The 2004 U.S. imports of Atlantic salmon approached $1 billion with approximately 80 percent originating from Canada. Globally, the production of feeds for aquaculture has been one of the fastest growing agriculture business sectors, but it has not been true for the U.S. market. Aquaculture production is centered in Asia. The United States or Canada is not listed in the top 10 of aquaculture feed production in the world.
The use of animal proteins and fats in aquaculture diets is accompanied with limited data compared to other animal species. This is especially notable when reviewing the literature for data to provide nutrient requirements and ingredient nutrient availability values for individual species of fish and shellfish. There are some 12,000 aquatic species identified around the world. Approximately 200 have been cultured, which provides for a wide variability in nutrient requirement recommendations. Much of the reported research in all aquaculture species has been conducted using ingredient substitution protocols, research protocols that are difficult to interpret in establishing species nutrient requirements. There are, however, volumes of studies that demonstrate that rendered animal proteins and fats have a high nutritive value for many aquaculture species. Formulated aquaculture feeds are among the most expensive animal feeds. They are high nutritive dense and generally are formulated using a liberal level of expensive ingredients. Virtually all of the animal proteins and fats can be utilized in part or total for many of the traditional ingredients.
Focused research and the effective transfer of knowledge are essential in meeting the challenge of producing more cost effective aquaculture feeds. FPRF has sponsored numerous research projects for a variety of marine cultured species, with a new project being initiated to target key aquaculture species that comprise the current and projected higher volume production. These species include carp, milkfish, shrimp, tilapia, catfish, mullet, sea bream, sea bass, salmon, and trout. The study will be conducted by Dr. Dominique Bureau and Dr. Ehab El-Haroun at the University of Guelph, Canada. The project encompasses the review of all current information and data on the nutritive value of rendered proteins and fats for the targeted species. It will also identify and test targeted uses for rendered animal proteins in these aquaculture feeds. An informative and attractive document directed at the primary aquaculture feed market will be the ultimate objective.
The projected growth and importance of the aquaculture production industry commands that the versatility, economic, and adaptability of rendered animal ingredients be major components of the diets used.
Summary
Though much interest and priority is focused on the exploration of new use applications for animal by-product tissue, it is important to retain the value they possess as animal feed ingredients. Certainly there are many other alternative use opportunities in the industrial market, but the “take-home” message of this review is to be remindful that the feed markets for livestock, poultry, companion animal, and aquaculture production have established their value as feed ingredients. FPRF has entered into a new era of research focus with the development of the Animal Co-Products Research and Education Center at Clemson University, whose mission is to focus on improved and new use development and validation for the safety for animal co-products and rendering processes. The foundation has not voided its emphasis on research endeavors to support the nutrition and safe feed/safe food attributed to animal proteins and fats. It is paramount for the livestock/poultry, feed, and rendering industries to remain vigilant to the wants and needs of their marketplace and constantly “reorder their priorities.”
References available upon request.
August 2005 Render