• Poultry Day '98 Abstracts

Dr. Layi Adeola, Department of Animal Sciences

Dr. Adeola's research program emphasizes amino acid nutrition of nonruminant animal species and utilization of plant minerals by nonruminants. Also included are amino acid availability and amino acid-energy relationships, nutritional evaluation of non-traditional feedstuffs. The total program is aimed at improving the efficiency of lean meat production in nonruminant animals and minimizing the flow of potentially detrimental levels of nutrients through animal waste to the environment. Currently, he is working on the metabolizable energy values for ducks, because most of the diets employed for ducks were obtained from nutritional studies of domestic chicken. This arises because limited information is available on ducks and problems are normally encountered in collecting highly liquid excreta in duck metabolizable energy assays. Assays for AME in feed ingredients for birds commonly rely on total collection of excreta in trays placed under the birds housed in cages. Collection of highly liquid excreta in trays placed under the ducks is subject to error due to splatter arising from contact of forcefully ejected excreta with trays and contamination with feed, dander, or scales. In Dr. Adeola's laboratory,they have developed tube-feeding and excreta collection methods that offer means of precisely feeding known amounts of ingredients and accurately collecting contaminant-free voided excreta which are extremely vital for obtaining reliable values from metabolizable energy assays. The technique provides a viable alternative to pan collection. The methods are currently being used to provide data on metabolizable energy and amino acid digestibility values on a variety of feed ingredients and byproducts that have the potential of being used as feed ingredients.

    Dr. Todd Applegate  Work in Dr. Applegate's laboratory includes studies to determine that regardless of egg size, embryos from hens in early lay develop more slowly than embryos from older hens during the final week of incubation. Much of these developmental differences can be attributed to the hen investing proportionately more yolk into the egg as she ages, thereby allowing for a greater mass transfer of yolk lipid into the embryo to support growth. The age of the hen has also been shown to affect intestinal maturity at hatch and has extended effects on glucose homeostasis during the acclimation period immediately after hatch. Continued research is focusing on the most optimal combination of nutrients to ease the hatchling through this critical transition period. 

 Dr. E. K. Asem, Department of Basic Medical Sciences

The goals of Dr. Asem's laboratory are to understand the mechanisms whereby locally produced bioactive molecules (intraovarian factors) in the regulation of ovarian follicular development and death (atresia). To develop, mature and eventually ovulate, an ovarian follicle must escape atresia or follicular death. After escaping atresia, the follicle must go through prescribed stages of development in order to release a fertilizable egg at ovulation. The processes of follicular atresia and follicular development are tightly regulated by both extraovarian and intraovarian hormones or factors. Greater emphasis has been placed by researchers on the roles of extraovarian regulators (for example pituitary gonadotropins) than on intraovarian factors. His laboratory intends to identify and characterize bioactive molecules in the ovary and demonstrate their physiological roles in follicular development or atresia. They will focus on the components of extracellular matrix proteins (especially components of basement membranes) that participate in the regulation of follicular development and atresia. Results from their studies will identify and explain the roles of intraovarian factors in the functions of the ovary. Moreover, these results will explain how the extraovarian and intraovarian factors interact to control ovarian function.

Dr. Kevin Hannon, Department of Basic Medical Sciences

Fibroblast growth factors (FGFs) are powerful regulators of bone and skeletal muscle development in vitro. It is important to note that in vivo, bone and skeletal muscle cells have the capability to synthesize many different members of the fibroblast growth factor family. The effects that these locally-made fibroblast growth factors exert on bone and skeletal muscle development is unknown. Therefore, a major goal of Dr. Hannon's research is to understand the importance of endogenously made fibroblast growth factors for control of long bone and skeletal muscle development in vivo. To address this goal, they are utilizing an avian-specific retroviral expression system. This system allows them to create a transgenic chicken by genetically regulating fibroblast growth factor expression in bone and skeletal muscle in ovo. They can then directly address the significance of each member of the fibroblast growth factor family for normal tissue growth and development. They have recently found that reducing the amount of fibroblast growth factor activity significantly retards the growth of skeletal muscle in developing chickens. This type of research has the potential to provide novel strategies towards improving growth and development in avian species. The retroviral expression system we use is also currently under refinement. Therefore, any research involving this procedure may also spawn potential practical strategies for clinical/commercial gene transfer in avian or mammalian species.

Dr. Albert J. Heber, Agriculture Engineering

Presently, Dr. Heber is evaluating turkey production facilities in southern Indiana to investigate the current ventilation strategies utilized for brooder and growout facilities and to discuss ventilation issues with the production staff. Ventilation strategies vary between and within companies. As compared to chicken and hog house ventilation, turkey house ventilation in southern Indiana has a greater use of manual controls and lower capital investment in environmental control equipment. It is apparently very important to keep ventilation controls simple so the growers can understand and operate them. Several lessons were learned during these investigations relating to size of sidewall openings, temperature controllers, control of ammonia, ridge ventilation, insulation levels and bird behavior.

In one experiment, using a two battery-operated temperature recorder system, temperatures were recorded every 30 seconds at specified locations in various facilities. In the first case, inside air temperatures were collected for six days in the second and third buildings in a row of three buildings. The average temperature of the second building was 0.6 F higher than in the outer building. Temperature differences were greater at night. The recorders were placed in the attic and the room, respectively, in a growout building between September 11-13. The inside temperature varied between 60 and 88 F and averaged 73 F whereas the attic temperature ranged from 49 and 121 F and averaged 75 F. The difference between attic and room temperatures varied between -20 F at night and 34 F during the day. Data is currently being recorded in two brooders, each with 4 week old birds. One brooder is a new building and naturally ventilated in hot weather. The other brooder is an old building and is mechanically ventilated year round.

Dr. Patricia Y. Hester, Department of Animal Sciences

For the past 20 years, Dr. Hester's laboratory has identified lighting, nutritional (compensatory growth), and litter management schemes to reduce the incidence of non-infectious leg abnormalities (valgus/varus deformities) in male turkeys. Her group is currently focusing efforts on the osteomyelitis complex, specifically trying to understand how Staphylococcus aureus enters the body of the bird and infiltrates the long bones and joints. Future research will investigate whether or not the respiratory tract serves as a point of entry for S. aureus. Her laboratory will attempt to sensitize birds to killed S. aureus via tracheal inoculations, followed by challenge of the foot-pad, to induce delayed type hypersensitivity. They have just recently established a model for delayed type hypersensitivity using subcutaneous injections of S. aureus for sensitization followed by foot-pad challenge. This model will serve as a positive control. Because subcutaneous injections are not normally a natural port of entry for Staph infections, they are now pursing the respiratory tract as a port of entry. They are hypothesizing that natural outbreaks of osteomyelitis may be due to birds being exposed on several occasions to S. aureus from the air they breathe followed by challenge, perhaps through contaminated needles used in vaccination or through ulcerated foot pads leading to delayed type hypersensitivity. Subsequent exposure to stress (e.g., nutritional stress such as feed restriction) is hypothesized to lead to outbreaks of osteomyelitis. Dr. Hester's laboratory is gathering preliminary data to determine if these specific series of events (sensitization to S. aureus ® challenge to S. aureus ® stress) are involved in the pathogenesis of Staphylococcosis. If preliminary data are promising, her laboratory will seek federal funding through the National Research Initiative so that we can work with live S. aureus retrieved from natural outbreaks of Staphylococcosis in poultry.

Dr. Don D. Jones, Agricultural and Biological Engineering

Dr. Jones' extension effort is directed at farmstead planning, layout of production facilities, the design and evaluation of housing and ventilation systems for livestock. Other extension effort is also in the area of manure collection, handling, storage and treatment of manure. On-campus activities include the development of multimedia educational programs for producers and students.

Dr. Mickey A. Latour, Department of Animal Sciences

A major focus of Dr. Latour's program is youth development and distance education. Currently USDA funds are being sought to implement distance learning materials for poultry. These proposals are designed to educate youth as well as provide supplemental materials to poultry farmers. Recognizing that on-campus training for specific information is not feasible for many youth organizations and poultry farmers, a commitment to bringing pertinent information using various distance learning technologies, such as teleconferencing, CD-ROM, World Wide Web, etc. are underway.

Another active part of his laboratory is the study of fat metabolism in newly hatched chicks. His interest resides in the nature of the egg throughout an entire production period. Specifically, eggs from young hen have a greater proportion of albumen vs. yolk, and that proportion switches as the hen becomes older. At the same time, the eggshell quality (e.g., increase in gases exchange and decrease in shell thickness) changes with time. Current evidence by his group, suggest the fatty acid profile of yolks are strongly influence by breeder age; specifically, their group noted a higher proportion of unsaturated fatty acids being deposited. Concurrent with the fatty acid changes is the alterations in lipid transport; that is, their group demonstrated that newly hatched chicks from young (first time egg laying broiler breeders) have a unique lipoprotein profile. Current thinking is that specific lipid transporters (lipoproteins) are grossly changed in concentration and believe this may affect chick survival during the early stages of placement. At present, however, there are no studies available on what causes this alteration in circulating lipoproteins in avian species. Therefore, the focus of his current work will be to kinetically model the transfer of lipids via lipoproteins particles in vivo. These studies are designed to track down the problem areas in vivo and in ovo by monitoring the production rates and clearance rates of specific molecules. Their goals are to identify the culprits behind the altered lipoprotein profile. For more information regarding my laboratory connect to http://ag.ansc.purdue.edu/poultry/mlatour.htm

Dr. T.L. Lin, Department of Veterinary Pathobiology and Animal Disease Diagnostic Laboratory

Turkey poult enteritis has contributed to significant economic losses in the turkey industry in Indiana for the last several years. Turkey poult enteritis, apparently due to a viral etiology, causes several diarrhea, weight loss, uneven flock growth, and mortality. A better understanding of the etiology, pathogenesis, pathology, immune responses, and molecular characteristics of the viral pathogen associated with turkey poult enteritis is the key to effective diagnosis, control, and prevention of this disease. The research is focused on: (1) characterization of turkey poult enteritis, (2) identification and characterization of the etiological agent causing turkey poult enteritis, (3) investigation of the specific humoral and cellular immune responses (4) development of immunological or molecular biological assays for viral antigen identification and antibody detection, and (5) study and comparison of molecular characteristics of different isolates from Indiana and other states. These studies will generate useful information for the development of sensitive and specific molecular biologically or immunologically based diagnostic assays for turkey poult enteritis as well as the construction of effective vaccines to protect turkey poults from this disease. Currently, turkey coronavirus from intestines of infected poults has been successfully propagated in turkey embryos, and purified from the embryo intestines by sucrose density gradient ultracentrifugation. The virions banded at a buoyant density of 1.18 to 1.20 g/ml in sucrose gradients. Turkey poult enteritis has been experimentally reproduced in seven-day-old turkey poults by oral inoculation of the purified turkey coronavirus. Marked atrophic enteritis was seen in turkey poults two days after oral inoculation. Turkey coronaviruses of Indiana, Minnesota or North Carolina origins have also been successfully detected by polymerase chain reaction. Development of enzyme-linked immunosorbent assay (ELISA) for antibody or antigen of turkey coronavirus to be used in acute outbreaks, recovery flocks, and routine health monitoring has been funded by Indiana Value Added Grant and work is underway.

Dr. Richard H. Linton, Department of Food Science

Dr. Linton’s primary research interests are improving the safety and quality of poultry products. He has worked with various poultry establishments in Indiana and nationwide to develop and implement food safety and food quality programs. At Purdue University, his work has been mainly directed toward Extension and outreach programs, but, he is also involved in basic research projects.

Most of his work has been dedicated to helping poultry plants establish Hazard Analysis Critical Control Point (HACCP) food safety programs. Under newly published United States Department of Agriculture (USDA) regulations, known as the "Pathogen Reduction Act," implementation of HACCP plans will be mandatory for poultry slaughtering and processing plants within the next few years. These new regulations will have a tremendous impact on the way poultry is handled and inspected. Inspections will be based on microbiological monitoring and control rather than visual observations. Closer interaction between Purdue University faculty and Indiana poultry companies will help make the transition to these new regulations smoother. Training programs and workshops regarding implementation of HACCP programs in the poultry industry will be offered starting this spring.

Dr. Linton also has an interest in indoor air quality. Controlling air flow can have an impact on the distribution and quantity of airborne microorganisms present in poultry processing environments. Movement of air can serve as a vehicle for cross-contamination which can affect product quality and/or make a product unsafe. In collaboration with the Agricultural and Biological Engineering Department and School of Health Sciences, a survey was performed for airborne microorganisms in various Indiana-based poultry slaughtering plants. This research indicated that it is important to ensure that air from highly contaminated areas (such as killing and picking operations) is not allowed to move into finished product areas (such as packing areas). Physical separation of air and/or ensuring adequate exhaust of air in highly contaminated areas may be an effective way to improve both product safety and shelf-life.

Improving product quality and shelf-life is another interest of Dr. Linton. Using mathematical modeling, he has been able to help companies optimize storage and handling conditions leading to a safer and better quality product. Most of the models that Dr. Linton has developed describe the effects of various environmental conditions (like pH, temperature, moisture) that may affect growth of pathogenic or spoilage microorganisms or affect enzymatic reactions.

Dr. William M. Muir, Department of Animal Sciences

Dr. Muir conducted a study where chickens were selected for improved livability and egg production over a 12-year period (6 generations). Birds were selected on the basis of group performance of half-sib families housed in either 9- or 12-bird cages. Although selection was consistently based on performance of the group, to either 60 or 72 weeks of age, the trait of selection changed over the generations from egg mass (EM) per bird housed to a non-optimal index giving equal weight to eggs per hen per day (EHD) and total days survival (DS). In generation 7, selected (S), control (C), and commercial (X) lines were housed in either single- or 12-bird cages. Birds were not beak-trimmed and lights during the laying period were set to high intensity. Birds which died were replaced with extra birds of the same line. Performance was measured from 20 to 58 weeks of age. The residual record from 59 to 72 weeks of age was projected by linear regression. Annual performances (20 to 72 weeks) for C, X, and S, respectively, in single-bird cages were: eggs per hen housed (EHH, 251, 295, 266 eggs), EM (14.1, 17.9, 14.6 kg), mortality (M, O, O, 0%), hen housed days (HHD, 365, 365, 365 days), and EHD (69, 81, 73%). In 12-bird cages performances were respectively: EHH (198, 193, 217 eggs), EM (11.0, 11.5, 11.7 kg), M (54, 89, 20%), HHD (488, 557, 403 days), and EHD (40.6, 34.6, 53.8%). In 12H cages S hens had better feathering than either C or X.

Dr. John A. Patterson, Department of Animal Sciences

Dr. Patterson is interested in intestinal microbiology. Currently, the main focus of his research is identifying factors affecting microbial interactions and manipulation of intestinal microbial populations to enhance animal performance, animal health, human food safety and to reduce excretion of environmental pollutants and odors.

It is becoming increasingly clear that the types and activities of microbes in the intestinal tract can have dramatic effects on the animal and on environmental pollution. The predominant microbial population acts to inhibit colonization and infection by pathogens. When activities of this population are disrupted and reduced there is an increase in incidence and severity of gastrointestinal disease. Increasing the numbers of certain bacterial groups (lactobacilli, bifidobacteria, etc.) has been shown to frequently improve animal performance and health. One can enhance numbers of specific microbial populations either by adding the microorganisms in the feed (prebiotic) or by feeding the animal a substrate that selectively enriches for that microbial population in the intestinal tract (prebiotic). A number of small carbohydrate compounds (oligosaccharides such as FOS, insulin, STOC, etc.) have been shown to specifically enrich for bifidobacteria. His laboratory has performed a number of experiments to determine the effect of the STOC oligosaccharide on animal performance and the conditions under which STOC is effective. They have used broilers, ducks and weanling pigs in these experiments. Also, they included a treatment where growth promotant antibiotics were fed as a positive control and response to STOC was similar to the response to the antibiotic. The greatest responses occurred when animals were stressed (80 F temperature) or had relatively low levels of supplementation of trace minerals and vitamins. Thus, feeding oligosaccharides improves animal performance, especially when the animals undergo stress, and one may be able to reduce supplementation of minerals in the diet. Currently they are examining the efficacy of reducing pathogens (salmonella) in market animals to improve human food safety. There are a number of stressors as animals are shipped from the farm to the packing plant and reducing the pathogens on farm prior to shipping should reduce the level of food contamination at the packing plant.

Odors produced from animal waste are becoming an important problem for the livestock industry, impacting operation of existing facilities as well as location of new facilities. These odors are the result of activities of specific microbial groups. Currently, they are examining the effect of feeding a number of compounds on odor production in the intestine and in simulated pit systems. Several compounds have been shown to reduce odor production and are now examining both the efficacy and the mechanism by which these compounds work. Phosphorous may soon regulate the amount of manure applied to land, so reduction of phosphorous excretion is important. Presently, they are examining the effect of feeding broilers a yeast with high phytase activity. In addition to releasing more of the bound plant phosphorous, yeast have been shown to improve animal performance.

Dr. A. L. Sutton, Department of Animal Sciences

Manure management is an important component of poultry production with challenges confronting the industry. These include: 1) sufficient land to apply manures without significant nutrient buildup in soil and adverse effects on water quality; 2) odors from production units and land application practices causing adverse neighbor relations; and 3) controlling building environment to reduce physiological and disease stressors. Following is a summary of some poultry waste research and potential new research areas. In cooperation with the School of Veterinary Medicine, several studies were conducted to determine the effects of litter conditions and management, litter sources and litter treatment on turkey performance, aspergillosis and leg abnormalities. Aspergillosis, air sacculitis and pneumonia were increased with high humidity, stirring litter and use of hardwood shavings. Stirring and high humidity increased bird mortality. Leg abnormalities were higher with hardwood shavings and high humidity. Body weight gains and feed consumption were improved with low humidity and pine shavings. Stirring did not affect gains or feed consumption, but aerial ammonia was increased with stirring and high humidity. Mold tended to be higher in hardwood shavings compared to pine or rice hulls. Mold inhibitors, ammonium propionate (Luprosil-NC®) and thiabendazole, tended to increase body weight gains in high humidity, reduced leg abnormalities, reduced litter coliforms and molds, reduced mortality and tended to reduce aspergillosis and air sacculitis.

Dr. Bruce A. Watkins, Department of Food Science

The primary research focus of Dr. Watkins' laboratory is food lipids and poultry products. The long-term goal of this research is to gain a better understanding of how individual fatty acids and plant phytochemicals can improve the nutritional quality and safety of foods. The objectives are to: 1) characterize the physiological actions of specific polyunsaturated fatty acids, 2) develop rapid methods for quantifying lipids, and 3) evaluate the functional components of foods. Consumer demand for low-fat foods, leaner meats, and functional foods has prompted scientists to change the fat composition of foods to help reduce heart disease and cancer which are responsible for one million the balance between and amount of individual fatty acids in foods that would decrease risk of disease. His group has developed research paradigms to study the beneficial effects of polyunsaturated fatty acids and plant phytochemicals. His research is a crosscut approach to food science and nutrition aimed at improving diet and health. For objective one they have conducted investigations on dietary fats and bone modeling. This research suggests that bone formation in broilers can be enhanced by feeding diets containing certain ratios of polyunsaturated fats and with supplemental vitamin E. In experiments with avian growth plate chondrocytes they observed that linoleic acid reduced collagen synthesis to impair bone growth but chondrocyte activity was restored with the addition of vitamin E. The research on bone and cartilage in poultry suggests that bone growth can be influenced by dietary fats and antioxidant nutrients.

The second research objective is the use of magnetic resonance (MR) to characterize the fatty acid composition of edible oils, poultry products, and batch-run hydrogenated vegetable oil. These studies showed a high positive correlation between MR measurements and the PUFA and monounsaturated fatty acid content in edible oils and in egg products. The MR method also appeared promising for predicting the degree of saturation in hydrogenated vegetable oils to improve quality control during the production of edible fats.

The third research objective is directed at studying plant phenolics and flavonoids. These compounds are reported to possess several properties that benefit health. Currently, they are performing research to characterize their antioxidant effects in cell culture and to evaluate their role in functional foods. As they study the PUFA and plant phytochemicals they look for application to the poultry industry for developing value added products.

Dr. Ralph E. Williams, Department of Entomology

Research in Entomology at Purdue University relates to the integrated management of arthropod pests of livestock and poultry. Poultry related research is focused on developing integrated control systems for litter beetles and flies in poultry production facilities. The house fly, lesser mealworm, and hide beetle contribute as vectors of both human and poultry pathogens and are often the source for nuisance complaints to residences surrounding egglayer installations. As urbanization and rural non-farm residences increase, poultry producers will be faced with increasing pressures to control fly and beetle populations. Poultry producers also focus on control of these pests because flies discolor eggs and facilities with fecal and regurgitation spots and often annoy poultry workers; while litter beetles affect the poultry house structure by their destruction of insulation and wood. Control of flies and beetles in poultry operations must involve technologies compatible with current production practices. Insecticide dependency has necessitated considering control alternatives due to limited choices of insecticides and application methods available; the rapid development of pest resistance to insecticides; buildup of insecticide residues in animal tissues and products; changes in egglayer systems; greater awareness and regulation of environmental consequences of agricultural practices; concern for cost effectiveness in egg production; and a realization that flies and beetles cannot be eradicated but it necessary to maintain a workable control program throughout the year. Emphasis is being placed on evaluating current practices for controlling these poultry pests, and developing new insecticide formulations and alternative control methods. When incorporated in an integrated pest management system, results of this research can have a significant impact on reducing the dependency of chemical insecticides for control of these pests and provide environmentally safe year round control alternatives.

Dr. C.C. Wu, Department of Veterinary Pathobiology and Animal Disease Diagnostic Laboratory

Infectious bursal disease (IBD) caused by infectious bursal disease virus (IBDV) affects the bursal lymphocytes of young chickens, resulting in bursal atrophy, immunosuppression, reduced weight gain and feed efficiency, and increased mortality. Immunosuppression may increase susceptibility to other bacterial or viral diseases as well as interfere with various vaccination programs. Infectious bursal disease is generally controlled by vaccination with live or dead virus vaccines. However, outbreaks of this disease still occur. The problem lies in that not only some vaccine viruses are pathogenic, but many variant strains emerge in the field due to vaccination pressure and the nature of RNA virus. In order to effectively control IBD, identification of IBDV serotypes and strains in the field for implementing the vaccination program as well as understanding the pathogenetic mechanisms are essential. The goals of one project in her laboratory are: (1) to develop molecular assays for rapid and specific detection and identification of field IBDV, (2) to analyze the existence of cell surface receptors for IBDV, (3) to identify specific microenvironmental changes during IBDV infection, and (4) to explore anti-IBDV strategies by antisense oligonucleotides and ribozymes. They have successfully developed one set of oligonucleotide primers using polymerase chain reaction (PCR) to detect serotypes 1 and 2 IBDV, including classical, variant, vaccine, and field strains. They have also developed two sets of oligonucleotide primers in a multiplex PCR to detect and differentiate IBDV serotypes 1 and 2. In addition, several genes from bursae that were differentially expressed during IBDV infection have been detected. One was ferritin gene which may have been associated with bursal lymphocytolysis in IBDV infections. Success in the attempts mentioned above will contribute to the production of effective genetically engineered vaccines and construction of transgenic chickens resistant to IBDV infection.

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