Location: Livestock Behavior Research2018 Annual Report
The long-term objective of this project is tightly focused to optimize animal welfare and productivity under modern farming conditions. The approach is to focus on animal behavior and the cumulative effects of internal biological changes, to assess where challenges may exist and to develop alternative management strategies; and to determine how changes in behavior relate to physiology and productivity. We will focus on the following objectives: Objective 1: To develop measures of animal welfare that are science-based and informative under industry conditions and practices. 1.A. Determine the thermal preference of sows and their physiological response during a heat stress event. 1.B. Assess the use of non-linear methods of measuring heart rate variability to determine if they can be used to assess pain in pigs and calves. 1.C. Expand chronic pain markers in dairy cow and sow leukocyte mRNA that create a profile of chronic pain that may be attributed to housing. 1.D. Evaluate tear staining as a welfare indicator in pigs. Objective 2: To determine the impact of production practices and environmental factors on animal welfare. 2.A. Determine the influence of the auditory environment of sows and its influence on maternal behavior and crushing. 2.B. Simultaneously enhance the thermal environment of sows and piglets to increase sow comfort and piglet survivability. 2.C. Evaluating the impact of in utero heat stress on postnatal behavior and stress response in pigs. Objective 3: To optimize animal husbandry to improve animal welfare and farm productivity. 3.A. To evaluate the effects of a dietary synbiotic (Lactobacillus + FOS + ß- glucan) in combination with a nutraceutical substrate (L-glutamine) on pig health and productivity after weaning and transport stress. 3.B. Probiotics to support development of dairy calf respiratory immunity. 3.C. Determine if probiotics prevent osteoporosis in laying hens. 3.D. Reduce heat stress in broiler chickens by activating the microbiota-gut- brain axis using synbiotics. 3.E. Reduce social stress in laying hens by prenatal modification of the serotonergic system with tryptophan. 3.F. Determine the effects of environmental enrichment on welfare and productivity of swine at all stages of production.
The long-term objective of this project is to optimize animal welfare and productivity. The approach is to focus on animal behavior, the outward expression of the cumulative effects of internal biological changes, to assess where challenges may exist and to develop alternative management strategies to solve these challenges. This project will examine animal agricultural practices, using behavior, physiology, immunology, and neurobiology. The project’s focus is on 3 significant areas of concern: 1) instances in which animals may experience pain or distress, 2) morbidity or mortality, and 3) the deleterious effects caused by climate variability. The varying expertise of the ARS scientists will be utilized to work together on multiple projects to address the primary challenges to animal welfare that are characteristic of the production systems for dairy cattle, swine and poultry. Our ultimate goal is to: 1) identify objective measures of distress, pain, and morbidity, 2) determine how specific production practices impact animal welfare, and 3) develop production practices to optimize welfare in a manner that also sustains and promotes productivity.
Sub-objective 1.A. Determine the thermal preference of sows and their physiological response during a heat stress event. Data collection for the thermal preference testing of sows was completed. Data is currently undergoing analysis and interpretation. Two thermoclines were constructed and sows at three reproductive stages (open, mid-gestation, late-gestation) were allowed free access to a thermal gradient. Sows were video-recorded to assess thermal preference over a 24-hour period. This project was in collaboration with researchers at Purdue University. Sub-objective 1.B. Assess the use of non-linear methods of measuring heart rate variability to determine if they can be used to assess pain in pigs and calves. Heart rate data has been collected from calves during disbudding and piglets during castration. All data is currently being analyzed. Sub-objective 1.C. Expand chronic pain markers in dairy cow and sow leukocyte mRNA that create a profile of chronic pain that may be attributed to housing. Animal, laboratory, and analysis work was completed. These data show that concrete flooring primes the cows over time for chronic pain. Sub-objective 1.D. Demonstrate that the amount of tear staining in weaner pigs is an indicator of stress and also related to clinical health. Two studies were carried out examining the effects of imposed stressors on tear staining in weaned and grow-finish pigs. In one study, tear stains increased in response to weaning, transportation and mixing, especially in those piglets fed diets without ingredients to help piglets cope with weaning stress. In a second study, tear staining was seen to increase prior to a tail-biting outbreak, indicating that it could be a predictor of an important welfare issue. Sub-objective 3.A. To evaluate the effects of a dietary synbiotic (Lactobacillus + FOS + ß-glucan) in combination with a nutraceutical substrate (L-glutamine) on pig health and productivity after weaning and transport stress. Piglets were weaned and transported for 12-hours. Following transport, all pigs were group housed and provided 1 of 5 diet treatments for 14 days (antibiotic free, antibiotics, 0.20% L-glutamine, synbiotics, 0.20% L-glutamine + synbiotics). During this time behavior, stress response, intestinal physiology, and production was assessed. Tissue and blood samples are currently being analyzed and data will be interpreted and prepared for write-up. Sub-objective 3.D. Synbiotic supplements reduce heat stress response in broiler chickens. The heat stress (HS) study was initiated, and behavioral, physiological and production data were collected. The results suggest that the synbiotic supplement may prove to be an important management tool for the broiler industry to diminish the negative effects of HS, potentially safeguarding the welfare and production of broiler chickens, particularly in areas that experience hot climates. Sub-objective 3.F. Demonstrate that providing beneficial enrichment materials to swine will decrease problem behaviors and improve welfare and productivity. Two studies have been carried out to investigate what properties of enrichment objects might be important to incorporate into further studies. One study has examined the provision of fabric to individually-housed pigs undergoing multiple behavioral and physiological measurements. A second study has examined provision of a variety of objects (foam, plastic, metal) at different stages of production on investigatory behavior. Data from both studies are undergoing further analysis, but preliminary results indicate that destructible objects (fabric, foam) elicit a greater range of manipulation than hard, non-destructible objects (plastic, metal).
1. Concrete floors are a causative factor contributing to chronic pain in dairy cows. There is a high incidence of lameness in dairy cows which is a welfare concern as well as an economic burden to producers. Cows are typically housed on concrete floors to allow daily cleaning to decrease the incidence of disease. ARS researchers in West Lafayette, Indiana, gave cows access to rubber flooring or concrete alone. The results suggest that rubber flooring affected immune function and pain receptors such that cows on concrete mounted an immunological and pain response when not provided access to rubber floors. These data show that concrete flooring primes the cows over time for chronic pain. Producers may be able to decrease the chronic pain by providing cows a more resilient surface on which to stand.
2. Increasing the incidence of beneficial micro-organisms in the stomach can help to decrease heat stress in broiler chickens. Broiler chickens are particularly susceptible to heat stress due to their large size to body mass ratio. Hyperthermia is a significant welfare problem for broilers as well as an economic loss for producers. To combat the negative effects of heat stress on broiler health and well-being, adequate ventilation has been used. However, as cooled air moves down the length of the chicken house, air temperature increases from internal heat loads, and thus birds furthest away from the inlets are not cooled as effectively. ARS researchers in West Lafayette, Indiana performed a study to examine the effects of a dietary micro-organism supplement on the behavioral patterns and growth performance of broiler chickens exposed to heat stress. The results suggest that the micro-organism supplement may prove to be an important management tool for the broiler industry to diminish the negative effects of heat stress particularly in areas that experience hot climates.
3. Discovered an antibiotic alternative for newly weaned and transported piglets. Weaned and transported pigs are inherently stressed by these procedures which are unavoidable. Traditionally, antibiotics have been used to help these compromised animals to prevent disease and morbidity. Currently, antibiotic use is being curtailed and alternatives must be identified to ensure the health and welfare of swine during these procedures. ARS researchers in West Lafayette, Indiana, conducted an experiment to determine the threshold for efficacy of L-glutamine (an essential amino acid) as an antibiotic alternative for swine producers following weaning and transport. It was determined that a range between 0.20 and 0.50% was the level at which L-glutamine would provide a positive effect on swine welfare and productivity. These results can be directly utilized by swine nutrition companies in the development and marketing of the antibiotic alternative for use in the swine industry. These results will provide the swine industry with the most effective level to provide L-glutamine to pigs following weaning and transport as an alternative to antibiotics.
4. Developed and validated a non-invasive method of determining intestinal permeability in pigs. When studying the adverse effects of heat stress in swine it is important to know how stressed they are by determining to what degree their intestines have been damaged by a heat stress event. Traditional methods have required that the pigs be euthanized to examine the intestines. Development of alternative methods that didn’t require the pig to be euthanized would be advantageous. ARS researchers in West Lafayette, Indiana, developed and validated a non-invasive method of determining intestinal permeability in pigs by refining and developing a protocol for the use of the mannitol/lactulose test (combination of a sugar and laxative) currently used in humans. This method does not require the euthanasia of pigs thereby allowing researchers to reduce the number of pigs used in research, repeatability of testing on the same animal and reduces the cost of research. These results are expected to provide researchers with a more advanced procedure to determine the impact of various stressors, feed additives and environmental influences on intestinal health in pigs.
5. Developed a prediction equation to estimate the core body temperature of chickens from facial skin temperature. The study of heat stress in poultry relies on accurate measurement of core body temperature. However, current methods require physical restraint of the birds which can cause the body temperature to increase, providing inaccurate measurements. ARS researchers in West Lafayette, Indiana, developed a prediction equation to estimate core body temperature from facial skin temperature in chickens. The equation utilizes the inputs of bird sex, time, and facial skin temperature and can predict core body temperature with 100% agreement based on data analysis. This equation is expected to help researchers collect more accurate body temperature data in experiments without having to rely on handling animals and manually taking temperatures, which can artificially elevate body temperature. In addition, it may have practical applications for poultry producers to determine when their birds are suffering from heat stress or whether their flocks have a fever or illness.
6. Provision of beneficial micro-organisms differentially affect cattle immunity. Respiratory disease is a critical problem with young calves and older feed lot calves. Probiotics (beneficial micro-organisms) are used for enteric health in both of those instances, but little is known of probiotics ability to enhance immunity of the respiratory tract. ARS researchers in West Lafayette, Indiana, conducted a study to show a diverse response by immune cells to 9 different probiotic bacteria and 2 synbiotics (probiotics plus nutrients necessary for them to flourish). Two of the probiotics (Propionibacterium freudenreichii) and (E. faecium) were most immunomodulatory compared with controls. However, one appeared to be suppressive and the other stimulatory to immune cell function. The results will help determine the best probiotics to use for selected purposes. This research will help producers determine whether feeding a commercially available probiotic in milk replacer and then dry feed will improve respiratory immune cell functions, and thus cattle welfare and productivity.
7. Demonstrated that short-term dietary modification can have long-lasting effects on behavior, cognition and welfare in pigs. Via the gut-brain axis, feeding of different diets to pigs, especially early in life, may result in behavioral differences and influence ability to cope with stress. ARS researches in West Lafayette Indiana, conducted two studies that demonstrated that early feeding of different diets affected gut microbiota, behavior and welfare. Pigs fed a synbiotic or L-glutamine coped better with stressful events such as weaning, transportation and mixing and had cognitive advantages, being better able to perform a variety of behavioral tests. There were also differences in gut microbial populations. The results will help to determine which microbiota should be encouraged to enable pigs to cope with stress, and aid the design of diets to promote these populations.
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Johnson, J.S., Aardsma, M.A., Duttlinger, A., Kpodo, K. 2018. Early life thermal stress: Impact on future thermotolerance, stress response, behavior, and intestinal morphology in piglets exposed to a heat stress challenge during simulated transport. Journal of Animal Science. 96(5):1640-1653. https://doi.org/10.1093/jas/sky107.
Yan, F., Murugesan, G., Cheng, H. 2018. Effects of probiotic supplementation on performance traits, bone mineralization, cecal microbial composition, cytokines, and corticosterone in laying hens. Animal. 1-9. https://doi.org/10.1017/S175173111800109X.
Wang, W., Yan, F., Hu, J., Huang, X., Cheng, H. 2018. Supplementation of Bacillus subtilis based probiotic reduces heat stress-related behaviors and inflammatory response in broiler chickens. Journal of Animal Science. 96(5):1654-1666. doi:10.1093/jas/sky092.
Abdelfattah, E.M., Lay Jr, D.C., Marchant Forde, J.N., Karousa, M.M., Schutz, M.M., Eicher, S.D. 2017. Short communication: Effect of age at group housing on behavior, cortisol, health, and leukocyte differential counts of neonatal bull dairy calves. Journal of Dairy Science. 101(1):596-602. https://doi.org/10.3168/jds.2017-12632.