Rutgers School of Environmental and Biological Sciences [Dept. of Animal Sciences]

Major Areas of Research

The research mission of the Department of Animal Sciences is to develop and enhance excellence in basic and applied research in focused areas within Animal Science. As the only entity in the state that addresses the needs of New Jersey animal agriculturists, we are recognized as regional leaders in animal sciences. The Department of Animal Sciences serves not only New Jersey animal producers and processors but also a significant number of biotechnology and pharmaceutical companies with an interest in animal health. To this end, the departmental faculty constitute a cohesive, yet diverse body, implementing novel ideas in molecular biology in research in animal science while at the same time maintaining their understanding of practical on-farm problems such as feeding and nutrition and optimizing growth and well-being in animals. The research interests of the Animal Sciences faculty are focused in the following areas: Endocrinology and Growth; Equine Science; and Sustainable Animal Agriculture.

I) ENDOCRINOLOGY AND GROWTH

Endocrinology represents a major common interest that bridges the multidisciplinary research programs of the majority of the departmental faculty. Collectively, these faculty conduct a broad range of endocrine-related research encompassing both agricultural as well as biomedical applications. The endocrine and growth-related research described here includes studies in farm animals, laboratory animals and lizards as well as both animal and human cell lines. Specifically, research is focused on the hypothalamic/pituitary control of reproduction, reproductive tissue growth and remodeling, the neuroendocrine axis of stress, hormonal control of reproductive behavior and developmental regulation of growth. Additionally, the faculty bring unique skills and resources ranging from expertise in whole animal approaches, protein chemistry and cell and molecular biology.

Juan P. Advis is presently conducting research to elucidate the neuroendocrine mechanisms controlling reproduction and evaluating how ethanol affects this regulatory system and alters reproductive function. He uses ewes as the experimental animal model and studies in vitro and in vivo peptide release from the hypothalamus. His studies have established the mechanism by which steroids control neuroendocrine hormone secretions and maintain reproductive cycles. His research has also established nutritional influences on puberty development. His current research focuses on ethanol's actions on the neuroendocrine system. His future research plans include identification of the relationship between neuroendocrine hormone synthesis, secretion, and degradation and how biological, environmental, and nutritional cues influence this relationship and affect reproduction.

Carol Bagnell is studying growth and remodeling of healthy and cancerous tissue of the reproductive tract. Factors which regulate the production, action and receptors for locally produced hormones, growth factors, and adhesion molecules are under investigation in her laboratory. She has demonstrated that the trophic effects of relaxin in reproductive tissues are independent of systemic steroids and involve increases in gap junctions, angiogenesis, connective tissue proteases and IGF-I. In addition, Dr. Bagnell has evidence that the cell adhesion molecule, epithelial cadherin, is expressed in healthy ovarian cells and is required for normal growth and development. Her future research plans include assessing the role of ligand-independent activation of the estrogen receptor in relaxin action and the regulation of adhesion at the gene and protein level in human ovarian cancer cells. She plans to incorporate transgenic and gene therapy technologies in her research to understand the role of cell adhesion in ovarian tumor growth and metastasis.

Wendie Cohick is examining the role of the insulin-like growth factors in regulating mammary gland physiology and tumorigenesis. Of the multiple IGF binding proteins (IGFBP) made by bovine mammary epithelial cells, she has shown that IGF specifically stimulates the synthesis of IGFBP-3. When these cells are genetically engineered to over-express IGFBP-3, they exhibit enhanced responsiveness to IGF-I in terms of DNA synthesis. Recent work in her laboratory indicates that the mechanism involves an enhancement of the IGF receptor-mediated signal transduction cascade through the phosphatidyl inositol 3-kinase pathway via increased activation of AKT-1. In addition to investigating the physiological role of IGFBP-3, Dr. Cohick is studying the transcriptional and posttranscriptional regulation of the gene. Her future research plans include investigating an intracellular role for IGFBP-3 in IGF-mediated cell cycle progression and tumor metastasis. She plans to use DNA microarray and gene knock-out technologies in her studies to understand the role of the IGF/IGFBP system in these processes.

Julie Fagan's research focus is on the enzymes that break down proteins and compounds that inhibit specific proteases and the mechanisms by which they regulate the many biological and pathological processes (blood clotting, digestion, growth, metabolism tissue remodeling, infection, cancers). Some of Dr. Fagan's research interests include the effects of antioxidants, reactive oxygen species and environmental factors in heart disease, cancer and infection.

Harold Hafs' primary research interest is in the induction and synchronization of estrus in cattle using intravaginal progesterone inserts. In a nationwide study of more than 1,900 beef cows, beef heifers and dairy heifers, Dr. Hafs found that progesterone inserts advanced the time of first estrus. Pregnancy rates were unaffected in beef cows and dairy heifers; however, in beef heifers with progesterone inserts the pregnancy rate was significantly improved. While commercial products are available for control of estrus in cattle, no similar products are labeled for use in pigs or horses in the US. Thus, in the future Dr. Hafs is interested in creating products to control estrus in pigs and horses. The broad aim here is to advance and synchronize the time of ovulation in pigs and horses, such that each female need be mated only once during an estrus. The tools to accomplish this goal will be sustained release formulations of gonadotropin releasing hormone, estradiol and progesterone.

Henry John-Alder's research focuses on the endocrine causes and ecological/evolutionary consequences of physiological variation among individual animals in the wild. His most recent work investigated the roles of steroid hormones in mediating environmental modulation of exercise performance in lizards in conjunction with DNA fingerprinting to investigate reproductive correlates of exercise endurance in the wild. His findings described substantial seasonal and individual variation in exercise endurance that is partially regulated by seasonal and social changes in testosterone and corticosterone. However, this ecologically relevant physiological trait was not correlated with habitat use, access to mates, or reproductive success. Two new projects are underway, building from the previous work. First, in collaboration with Rocco Carsia, Dr. John-Alder is investigating hypophysial versus adrenocortical cell modulation of variation in the stress response. Second, Dr. John-Alder has initiated a comprehensive comparative investigation of ultimate and proximate mechanisms of sexual size dimorphism. These studies will ultimately test the hypothesis that sex steroids lead to differential expression of growth-promoting genes, including pituitary growth hormone and hepatic IGF-1.

Barry Jesse is studying the molecular basis for rumen epithelial development in the neonatal lamb. Studies from his laboratory demonstrate the importance of butyrate, a volatile fatty acid produced in the rumen, in rumen epithelial development. Dr. Jesse has isolated and characterized several cDNA clones corresponding to genes expressed in mature, but not neonatal, rumen epithelium. Genomic clones corresponding to two of these cDNA clones, type I carbonic anhydrase and type II small proline-rich protein gene have been isolated. In the future, Dr. Jesse plans to identify the specific transcription factors responsible for expression of these genes. This will allow characterization of the molecular events involved in triggering post-natal rumen epithelial development in the lamb. In addition, many of the cDNA clones characterized appear to be unique to sheep, while others are related to genes identified in the human and mouse. Thus, future research will focus on comparative genomics, addressing the evolutionary relationship of the sheep genes to the human and mouse genes.

Larry Katz is interested in the endocrine, environmental, and social factors that affect reproductive behavior and performance using sheep and goats as animal models. Behavioral endocrine studies in goats in Dr. Katz's laboratory have focused on the expression of estrous behavior in the female. For example, he has characterized progesterone's facilitation and inhibition of estradiol-induced sexual behavior in female animals. There is also evidence for androgen effects on sexual behavior in females. Dr. Katz has hypothesized that there are behavioral effects of androgens that are independent of estrogen-mediated behaviors. In addition, studies on social factors that influence reproductive performance in males are under investigation. One component of these investigations will examine the ability of female-female interactions to stimulate maximum sexual performance in males.

Dipak Sarkar's research goal is to understand the growth and differentiation of the neuroendocrine cells controlling reproduction and immune function, and how alcohol abuse, natural and environmental estrogens, and stress alter these processes at the cellular and molecular levels. Current interests include the development of the neuroendocrine axis of stress; the effects of alcohol on the fetus; opioid peptides' control of natural killer cell cytotoxicity; the role of paracrine and gap-junctional communications in estrogen-induced pituitary tumors; the role of transforming growth factor-ß and its binding proteins in regulation of growth, differentiation, and apoptosis in pituitary lactotropic cells and ß-endorphin-secreting neurons; the use of gene knock-out and transgenic approaches in the study of lactotropic and ß-endorphin cells growth and differentiation; the detection of estrogenic properties in environmental compounds and their effects on reproductive development; and the use of gene therapy technology in controlling reproductive function.

II) EQUINE SCIENCE

Equine science research in the department focuses on improving the quality of life and well-being of horses, while ensuring the vitality and viability of the equine industry, statewide and nationally. The broad area of aging in horses and the effects of exercise on their well-being is a major interest of this group because this system provides an excellent model for answering questions about equine physiology, and the research may apply to human medicine as well. Faculty with research programs in equine science include specialists in nutrition, immune function, exercise physiology, endocrinology and reproduction.

Karyn Malinowski is studying aging and exercise and their effects on immune function in the equine athlete. Studies from her laboratory indicate that recombinant equine somatotropin has positive effects on age-related declines in body condition and nutrient utilization in geriatric mares. Dr. Malinowski's current research focus involves the effect of aging on immune function in horses and includes investigation of modalities (including hormone therapy) to reduce immunosenescence in the older horse.

Kenneth McKeever's research is focused on exercise and cardiovascular physiology with a particular interest in baroreceptor function and renal and neuroendocrine control of blood pressure and blood volume and fluid and electrolyte balance. Dr. McKeever is interested in the endocrine control of cardiorenal function including the actions of agents such as endothelin, atrial natriuretic peptide and erythropoietin. On an applied level his research centers on the impact of ergogenic and ergolytic agents on equine performance. Dr. McKeever has also published some the first studies to demonstrate that aging alters the physiological response to exercise and thermal challenges in the horse. In the future, Dr. Mc Keever plans to continue to use the horse as a model to study the integrative physiological responses to exercise and environmental challenges. He plans to examine the effects of various drugs, nutriceuticals, and other ergogenic and ergolytic practices on the health and well-being of the athletic horse.

Sarah Ralston's research centers on the effect of diet on glucose metabolism in horses of all ages. She is interested in dietary prevention of osteochondrosis (OCD) and laminitis, diseases that cost the horse industry millions of dollars annually. Her research on nutrition of growing foals has resulted in altered feeding recommendations for rapidly growing foals and the development of a patented diagnostic test for foals at-risk of OCD. She is currently investigating pasture grasses and feeds that might prevent OCD and laminitis in predisposed horses. Dr. Ralston is also conducting research on transportation stress, handling and vitamin supplementation in an attempt to find ways to reduce "shipping fever" in horses transported long distances.

Carol Bagnell is interested in late-term pregnancy loss due to placental insufficiency and the possibility of using the hormone relaxin as a marker of placental function and fetal well-being. Evidence from her laboratory has established that low systemic relaxin is linked to placental problems and poor pregnancy outcome in Standardbred mares. Her laboratory has recently produced recombinant equine relaxin in a mammalian cell line. The availability of sufficient quantities of purified recombinant equine relaxin opens up exciting possibilities for new research and therapeutic applications for the hormone in the future. Her future research plans include the creation of a recombinant-based enzyme-linked immunoassay for use in veterinary clinics to monitor at-risk pregnant mares and basic research on factors that control placental production of equine relaxin.

III) SUSTAINABLE ANIMAL AGRICULTURE

Several of the research programs in the Department of Animal Sciences are focused on sustainable animal agriculture with positive economic and environmental impacts for the State of New Jersey. These applied research programs include: food waste utilization and recycling, nutrient and manure management, composting manure and wildlife damage control.

Michael Westendorf's research is centered on the recycling and processing of food waste into animal feed. The potential impact in this area is significant for decreasing landfill and processing costs and for making a new feedstuff available for animals. His research has resulted in a book entitled Food Waste to Animal Feed, edited by Dr. Westendorf and published by Iowa State University Press. Another area of research, of considerable significance to the environment, is Dr. Westendorf's work in the development of on-farm plans for use/disposal of manure. Manure disposal is a major problem for all animal industries worldwide. Disposal of manure is a management challenge for the small farmer and his research is directed toward finding new solutions.

James Wohlt's research using both positve and negative control diets clearly established the value of feeding supplemental yeast to dairy cattle that are fed corn silage-based diets during early lactation. Dr. Wohlt is also conducting research to identify and develop non-traditional feedstuffs, such as using by-products from fish processing and cannery industries and microbreweries, as alternative animal feeds. In addition, he is evaluating the use of pelleted, recycled newspaper as a safe, low-cost animal bedding material. Drs. Westendorf and Wohlt's research programs meet the goal of sustainability by decreasing the amount of food waste or newspaper which must be landfilled and provide farmers with inexpensive, nutritious feeds and bedding material which can be substituted for more expensive commercial products.

Larry Katz's applied research addresses another issue of agricultural sustainability: developing methods to manage wildlife populations, specifically white-tailed deer in suburban and urban areas. Sustainable agriculture co-exists with a healthy wildlife population that does not cause damage exceeding a producer's level of tolerance. As the associate director of the Rutgers University/NJAES Center for Wildlife Damage Control, Dr. Katz addresses the problems associated with over abundant deer populations, particularly in urban and suburban areas. His research has focused on the development and testing of attractants/baits to be used to lure animals to a site for treatment with potential reproductive inhibitors. In addition, his laboratory has studied several methods to inhibit reproduction in deer and are currently seeking chemical methods of sterilization. In collaboration with the Sarkar laboratory, he plans to determine the efficacy of gene transfer technology to control reproduction in deer. This research may also be significant in reproduction control of other species.

 

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