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Animal breeding reports in the Journal of Animal Science (JAS) and in its predecessor, Proceedings of the American Society of Animal Production, were counted and categorized. In 22 volumes of the Proceedings of the American Society of Animal Production, 155 articles had animal breeding content, of which 54% were research reports, 17% extension communications, and 28% syntheses or reviews. Several of the latter featured advice from the livestock industry to the scientific community. Thirty-one percent of articles concerned swine, whereas beef cattle, dairy cattle, and sheep each accounted for an additional 20%. In the 67 yr of JAS publication, 3,045 research papers were identified with animal breeding content, nearly half of them published since 1990. Growth in publication output was modest during the 1950s, robust in the 1960s through 1980s, moderate in the 1990s, and static in the 2000s. Important topics included genetic resource evaluation (a subject in 55% of all manuscripts), genetic parameter estimation, selection programs, and nonrandom mating systems. Maternal effects and genotype x environment interactions were featured in 17 and 15% of all manuscripts, respectively, whereas 6% dealt with a simply inherited trait. Only 4% of manuscripts included economic analysis of a breeding program or intervention. Interest in molecular biology and biometry has surged in the 1990s and 2000s. Approximately 50% of all papers involved cattle, a fifth of which concerned dairy cattle or beef x dairy crossbreds. A quarter of papers concerned swine, 15% concerned sheep, and 3% considered laboratory rodents, with the proportional contribution of sheep research decreasing across time. Authors from the Midwestern and Southern sections of the American Society of Animal Science had greater proportional contributions than Western and Northeastern section authors, and contributions of university and state experiment station authors outnumbered those of USDA-ARS authors. The proportional contribution of international authors increased across time, reaching 45% for the 2000s, as that of university and experiment station authors decreased and that of USDA-ARS authors remained fairly constant. Subjective analysis suggested substantial levels of creativity, innovation, and cooperation in JAS animal breeding research, a strong international perspective, but also a marked degree of imitation and repetition in subject matter content.

Meat has been important to human survival and personal enjoyment for thousands of years, and as societies become more affluent, the amount and quality of meat consumed increases. Ancient Egyptians are known to have consumed ground meat, whereas the Greeks and Romans enjoyed various types of sausages. Ground meat has been consumed throughout the world under various names and for several centuries. However, in recent years, microbial meat safety has become a major concern, and it appears that meat safety challenges will persist in future years. This paper provides a brief historical account of selected developments in microbiology, meat science, and safety, and associated industrial and regulatory highlights, and a brief overview of current and future food safety issues, concerns, and challenges.

During this centennial year of the American Society of Animal Science (ASAS), it is of interest to look back over the history of our Society and, in particular, to the many contributions made by researchers in the area of swine nutrition. A great number of basic and applied research studies involving the nutrition of weanling, growing, and finishing pigs, and gestating and lactating sows have been conducted by swine nutritionists during the past 100 yr. Most of these studies were conducted at universities by animal scientists or by the graduate students under their leadership. Others were conducted by nutritionists in the feed and pharmaceutical industries and government scientists at ARS/USDA research centers. Contributions were also made by animal scientists beyond our borders. Much of the research was published in the Journal of Animal Science during its 66 yr of existence. Before the first issue of the journal was published in 1942, some of the earlier studies were reported in the Proceedings of the Annual Meeting of the Society of Animal Production, the forerunner of ASAS. These research studies have progressively led to a better understanding of the role and utilization of dietary energy, protein, AA, carbohydrates, fats, minerals, and vitamins by pigs and have helped to quantify the nutrient requirements of pigs for various stages of growth, for sows during gestation and lactation, and to a limited extent, for boars. Determining the nutritional value of a wide array of feedstuffs, evaluating feeding strategies, and assessing the value of growth-promoting and carcass-enhancing agents have been important research contributions as well. To identify the particular studies that were among the most instrumental in contributing to our present knowledge of swine nutrition is, to say the least, a daunting assignment. To aid in this task, a survey of swine nutritionists was conducted in which they were asked to identify and rank the 10 most significant findings in swine nutrition during the past 100 yr. The results of that survey are presented in this paper.

Acute and subacute ruminal acidosis, bloat, liver abscesses, and polioencephalomalacia (PEM) were reviewed with respect to contributions published in the Journal of Animal Science (JAS) regarding these metabolic and digestive disorders in beef cattle. Increased grain feeding and expansion of the feedlot industry in the 1960s led to considerable research on acidosis, and early publications defined ruminal changes with acute acidosis. The concept of subacute acidosis was developed in the 1970s. Significant research was published during the 1980s and 1990s on adaptation to high-grain diets, effects of ionophores, and the development of model systems to study ruminal and metabolic changes in acidosis. Since 2000, JAS publications on acidosis have largely focused on individual animal variability in response to acid loads and the role of management strategies in controlling acidosis. Increased grain feeding also was associated with an increase in the incidence of liver abscesses, which were quickly linked to insults to the ruminal epithelium associated with acidosis. The role of antibiotics, particularly tylosin, in decreasing the incidence and severity of liver abscesses was a significant contribution of JAS publications during the 1970s and 1980s. Papers on bloat were among the earliest published in JAS related to metabolic and digestive disorders in cattle. Noteworthy accomplishments in bloat research chronicled in JAS include the nature of ruminal contents in legume and feedlot bloat, the role of plant fractions and microbial populations in the development of bloat, and the efficacy of poloxalene, ionophores, and, more recently, condensed tannins in decreasing the incidence and severity of bloat. Although less research has been published on PEM in JAS, early publications highlighting the association between PEM and ruminal acidity and the role of thiaminase in certain forms of the disorder, as well as more recent publications related to the role of sulfur in the development of PEM, are noteworthy contributions. Since the 1940s, outstanding and often-cited review articles have made JAS a highly visible source of information on these disorders. Thus, JAS has played a significant role as a repository for information pertaining to metabolic and digestive disorders in cattle and other ruminants, and it will no doubt continue to be a premier resource for information on these conditions during the second century of the American Society of Animal Science.

From a historical perspective, it is difficult to identify a specific date that launched the field of endocrinology. One "biomarker" of the inception of endocrinology traces back to Ernest Henry Starling, who first introduced the word hormone in a talk given in 1905 at the Royal College of Physicians in London (Starling, 1905). A historical look at the field of endocrine regulation of animal growth since 1905 conveys that countless scientists worldwide worked to advance the scientific evidence base, which led to the commercial development of hormone-based products that enhanced growth and beneficially changed carcass composition of meat animals. This review will discuss some of seminal contributions that include the discovery of hormones (like ST and beta-adrenergic agonists) that have been shown to play key roles in regulating growth and nutrient partitioning of livestock, the mechanisms by which these hormones act, and the development of products for application in animal agriculture.

Discoveries, understanding, and innovations in meat science during the last century have led to revolutionary changes in meat and poultry production, processing, marketing, and consumption. American Society of Animal Science members have made key contributions in most, if not all, categories of advancement. The first US university meat science program was begun in Minnesota in 1905. Use of mechanical refrigeration in the meatpacking industry, improved transportation and packaging, and home refrigeration provided more flexibility, variety, and consistency in meat and meat products in the early 1900s. Cooperative meat research was begun by 27 universities in 1925, with a focus on the observational characterization of carcass traits and composition, meat quality attributes, and causes of the wide variation in these variables. Scientific study of genetic, nutritional, and environmental influences on the growth, physiology, and postmortem biochemistry of muscle often used muscle-comparative investigations. Rigor mortis, cold shortening and thaw rigor, postmortem muscle metabolism, postmortem tenderization and tenderness variation, and postmortem myoglobin and lipid oxidation were studied vigorously in the 1960s and beyond, defining the biochemical bases for associated outcomes in fresh and processed products. Value-added benefits resulted from implementation of electrical stimulation, boxed beef and modified-atmosphere packaging, restructuring technologies, collagen recovery, and muscle profiling work. Isolation, purification, and definition of the primary structure and biophysical properties of the myofribillar and cytoskeletal proteins in muscle aided the understanding of contraction and postmortem changes. The role of Ca-dependent proteases in meat tenderness and muscle growth is being clarified. The chemistry of meat curing, meat emulsion formation, fermentation, and other processing methods led to new technologies, new meat products, and new benchmarks in product shelf life and quality. Meat safety assurance and our ability to manage the microbiological causes of food-borne illness and spoilage are imminently important now and in the future.

American Society of Animal Science members, publishing in Journal of Animal Science (JAS), completed research that resulted in understanding the estrous cycle of cattle, which led to the ability to inseminate cattle on a given day with pregnancy rates similar to those achieved by 21-d breeding by a fertile and sound bull. Research published in JAS led to understanding estrus, ovulation, the estrous cycle, and postpartum interval for cattle (1930s through 1960s) and hormonal factors affecting corpus luteum lifespan of cattle (1950s through 1980s). Research during the 1940s to 1960s, using gonadotropins and progesterone to manage the estrous cycle of cattle, established the concepts for estrous synchronization and stimulated commercial research directed at developing cost-effective progestogen estrous synchronization products, leading to commercially available products from 1967 through today (Repromix, melengestrol acetate, Syncro-Mate-B, controlled internal drug release). Prostaglandin F(2alpha) products were approved for estrous synchronization (1970s, 1980s), and GnRH products were approved for use in cattle to treat ovarian follicular cysts (1970s, 1980s). Research published in JAS was essential for understanding the biology of and potential value of both PGF(2alpha) and GnRH and contributed both to new knowledge and scientific bases for future Food and Drug Administration Center for Veterinary Medicine approval of those products. Research during the1980s through 2000s led to understanding ovarian follicular waves and described the timing of follicular recruitment, selection, dominance, and atresia; this research was essential for the ability to effectively manage follicles to achieve success with timed AI. The knowledge gained through research published in JAS resulted in development of the numerous estrous synchronization and breeding management protocols that are cost-effective and meet the breeding management needs of most beef and dairy enterprises.

Over the next quarter century in North America, the following eventualities are likely for physiology and endocrinology research with agricultural animals. 1) Total funding adjusted for inflation will change little but will come less from public sources, and most of that will be in the context of human health. Much of the privately funded research will be herd specific and remain proprietary. 2) The numbers of MS, PhD, and postdoctoral students probably will decrease, but research in the context of credentialing will remain important. 3) Resources such as expanded databases in genomics and proteomics, and remarkable new tools such as small inhibitory RNA will continue to become available, likely at a faster rate than in the previous 25 yr. 4) The huge amounts of data from production agriculture will make agricultural animals ideal models for some kinds of basic research, such as studying fetal programming, resulting in synergy with more applied research. Most of these experimental animals will be in private production herds and flocks, even when work is publicly funded. 5) The trend toward more interdisciplinary research will continue, especially considering interactions among reproduction, health, nutrition, selective breeding, management factors, and societal concerns; reductionist research probing deeper into cellular and molecular mechanisms will remain important, as will whole-animal approaches. 6) Agricultural animals are a product of evolution plus selective breeding. Insights drawn from the former will aid progress in the latter. One focus of research in physiology and endocrinology will be understanding heterosis, inbreeding depression, and epigenetic effects as it becomes possible to manipulate and identify the allelic structure of individual animals. 7) Additional insightful concepts will evolve that will simplify thinking in some respects, such as the maternal to embryonic shift in transcribed RNA in early embryos; however, animal biology will turn out to be even more complex than most of us currently imagine.

The last century of food animal agri- culture is a remarkable triumph of scientific research. Knowledge derived through research has resulted in the development and use of new technologies that have in- creased the efficiency of food production and created a huge animal production and food manufacturing in- dustry capable of feeding the US population while also providing significant quantities of high-quality food for export to other countries. Although the US food sup- ply is among the safest in the world, the US Center for Disease Prevention and Control estimates that 76 million people get sick, more than 300,000 are hospital- ized, and 5,000 die each year from foodborne illness. Consequently, preventing foodborne illness and death remains a major public health concern. Challenges to providing a safe, abundant, and nutritious food sup- ply are complex because all aspects of food produc- tion, from farm to fork, must be considered. Given the national and international demand and expectations for food safety as well as the formidable challenges of producing and maintaining a safe food supply, food safety research and educational programs have taken on a new urgency. Remarkable progress has been made during the last century. Wisdom from a century of ani- mal agriculture research now includes the realization that on-farm pathogens are intricately associated with animal health and well-being, the production of high- quality food, and profitability. In this review, some of the developments that have occurred over the last few decades are summarized, including types, sources, and concentrations of disease-causing pathogens encoun- tered in food-producing animal environments and their association with food safety; current and future meth- ods to control or reduce foodborne pathogens on the farm; and present and future preharvest food safety research directions. Future scientific breakthroughs will no doubt have a profound impact on animal agriculture and the production of high-quality food, but we will also be faced with moral, ethical, and societal dilemmas that must be reconciled. A strong, science-based ap- proach that addresses all the complex issues involved in continuing to improve food safety and public health is necessary to prevent foodborne illnesses. Not only must research be conducted to solve complex food safety is- sues, but results of that research must also be commu- nicated effectively to producers and consumers.

Pastures, forages, and grasslands dominate the landscape across the United States and support a large ruminant population that supplies the nation with value-added animal products. A historical perspective is presented of the innovations as they occurred in the Journal of Animal Science over the past 100 yr in pasture and forage research. Consideration was given to both animal and pasture perspectives. Areas given consideration from the animal perspective were schemes for feedstuff analysis, experimental design and statistics, forage sample preservation, indirect methods of measuring intake and digestion, TDN and energy, nutritive value, harvested forage, and innovations in the grazing environment. Areas given consideration from the forage perspective were a framework for forage-animal interface research, determining pasture yield, choice of stocking method, grazing management, partitioning of forage DM, near-infrared reflectance spectroscopy technology, antiquality constituents, and forage sample preservation. Finally, the importance was discussed of applying research results from the forage-animal interface to general ruminant nutrition research beyond the interface that is focused on altered diets.

The development of a beef industry, heavily dependent on corn utilization, began to occur in the 1940s. Begun as a means to add value to the grain while improving consumer acceptance of beef, corn has become an integral part of beef production. Developments in the 21st century including unprecedented cattle prices, changes in beef demand, bovine spongiform encephalopathy, surge in energy costs, pricing differentiation of cattle prices based on quality, and industry consolidation have dramatically changed the price of corn and cost of beef production. The future of the beef industry will be dependent on our ability to continue producing high-quality beef for a global market through effective use of genetics, new technologies, and economic management strategies.

One hundred years ago, there were more than 48 million sheep in the United States. In 1910, they were valued at $4/head, with 43% of income coming from the sale of sheep, lambs, and meat and 57% coming from wool. Over the years, fluctuations in this ratio have challenged the breeder and researcher alike. By 2007, sheep numbers had declined to 6.2 million, with the average sheep shearing 3.4 kg of wool (representing

We are a nation of dog lovers. Never before in our history have we spent more time, money, and emotional energy on a group of animals that are kept solely for companionship. Pet food sales are a multi-billion dollar industry, and pet owners are spending more than 11 billion dollars each year on veterinary care. This devotion is further illustrated by the exponential growth of the pet supply industry, including increasing numbers of pet superstores, play-parks, training centers, and doggie day care centers. During the 1980s, recognition of the human-animal bond led to serious study of the roles that dogs play in our lives. These studies have shown that pets provide significant benefits to our emotional, physical, and social well being. It is ironic then, that at a time when we recognize and appreciate our bonds with animal companions, dark elements of this relationship are equally pervasive. Animal shelters in the United States kill between 3 and 4 million dogs and cats annually. Dog fighting, although outlawed, has reached epidemic proportions in some areas of the country. Episodes of animal cruelty and neglect are reported with alarming frequency in the media; so frequently that discussions of the connection between animal cruelty and human violence have become daily parlance. How then did we come to have such paradoxical perceptions and treatment of our canine companions? This question is explored through an examination of the ancestry of the dog and the prevailing myths and facts about domestication. Historical and present-day perceptions of the wolf and the impact that these attitudes may have upon perceptions of dogs are examined.

Development of nutritional energetics can be traced to the 1400s. Lavoisier established re- lationships among O2 use, CO2 production and heat production in the late 1700s, and the laws of thermo- dynamics and law of Hess were discovered during the 1840s. Those discoveries established the fundamental bases for nutritional energetics and enabled the funda- mental entity ME = retained energy + heat energy to be established. Objectives became: 1) to establish re- lationships between gas exchange and heat energy, 2) to devise bases for evaluation of foods that could be re- lated to energy expenditures, and 3) to establish causes of energy expenditures. From these endeavors, the basic concepts of energy partitioning by animals were developed, ultimately resulting in the development of feeding systems based on NE concepts. The California Net Energy System, developed for finishing beef cattle, was the first to be based on retained energy as deter- mined by comparative slaughter and the first to use 2 NE values (NEm and NEg) to describe feed and animal requirements. The system has been broadened concep- tually to encompass life cycle energy requirements of beef cattle and modified by the inclusion of numerous adjustments to address factors known to affect energy requirements and value of feed to meet those needs. The current NE system remains useful but is empiri- cal and static in nature and thus fails to capture the dynamics of energy utilization by diverse animals as they respond to changing environmental conditions. Consequently, efforts were initiated to develop dy- namic simulation models that captured the underlying biology and thus were sensitive to variable genetic and environmental conditions. Development of a series of models has been described to show examples of the con- ceptual evolution of dynamic, mechanistic models and their applications. Generally with each new system, advances in prediction accuracy came about by adding new terms to conceptually validated models. However, complexity of input requirements often limits general use of these larger models. Expert systems may be uti- lized to provide many of the additional inputs needed for application of the more complex models. Additional information available from these systems is expected to result in an ever-increasing range of application. These systems are expected to have increased generality and the capability to be integrated with other models to allow economic evaluation. This will eventually allow users to compute solutions that allow development of optimal production strategies.

Development of nutritional energetics can be traced to the 1400s. Lavoisier established relationships among O(2) use, CO(2) production and heat production in the late 1700s, and the laws of thermodynamics and law of Hess were discovered during the 1840s. Those discoveries established the fundamental bases for nutritional energetics and enabled the fundamental entity ME = retained energy + heat energy to be established. Objectives became: 1) to establish relationships between gas exchange and heat energy, 2) to devise bases for evaluation of foods that could be related to energy expenditures, and 3) to establish causes of energy expenditures. From these endeavors, the basic concepts of energy partitioning by animals were developed, ultimately resulting in the development of feeding systems based on NE concepts. The California Net Energy System, developed for finishing beef cattle, was the first to be based on retained energy as determined by comparative slaughter and the first to use 2 NE values (NE(m) and NE(g)) to describe feed and animal requirements. The system has been broadened conceptually to encompass life cycle energy requirements of beef cattle and modified by the inclusion of numerous adjustments to address factors known to affect energy requirements and value of feed to meet those needs. The current NE system remains useful but is empirical and static in nature and thus fails to capture the dynamics of energy utilization by diverse animals as they respond to changing environmental conditions. Consequently, efforts were initiated to develop dynamic simulation models that captured the underlying biology and thus were sensitive to variable genetic and environmental conditions. Development of a series of models has been described to show examples of the conceptual evolution of dynamic, mechanistic models and their applications. Generally with each new system, advances in prediction accuracy came about by adding new terms to conceptually validated models. However, complexity of input requirements often limits general use of these larger models. Expert systems may be utilized to provide many of the additional inputs needed for application of the more complex models. Additional information available from these systems is expected to result in an ever-increasing range of application. These systems are expected to have increased generality and the capability to be integrated with other models to allow economic evaluation. This will eventually allow users to compute solutions that allow development of optimal production strategies.

Proteomics holds significant promise as a method for advancing animal science research. The use of this technology in animal science is still in its infancy. The ability of proteomics to simultaneously identify and quantify potentially thousands of proteins is unparalleled. In this review, we will discuss basic principles of doing a proteomic experiment. In addition, challenges and limitations of proteomics will be considered, stressing those that are unique to animal sciences. The current proteomic research in animal sciences will be discussed, and the potential uses for this technology will be highlighted.