Location: Livestock Behavior Research2016 Annual Report
Objective 1: Develop measures of swine well-being that are science-based and informative under industry conditions and practices; determine the impact of production practices and environmental factors, including climate change, on animal well-being. 1.A. Increase sow longevity by increasing articular cartilage health. 1.B. Decrease perinatal and neonatal piglet mortality. 1.C. Determine factors that influence aggression in pigs. Objective 2: Develop measures of dairy animal well-being that are science-based and informative under industry conditions and practices; determine the impact of production practices and environmental factors, including climate change, on animal well-being. 2.A. Identify a novel indicator of chronic pain in cattle. 2.B. Determine optimum age for grouping, group size, and need for individual partitioning of trough space for group-housed veal and dairy calves. Objective 3: Develop measures of poultry well-being that are science-based and informative under industry conditions and practices; determine the impact of production practices and environmental factors, including climate change, on animal well-being. 3.A. Prevent aggression in poultry by modification of the serotonergic system. 3.B. Develop intervention strategies for increasing heat tolerance in poultry. 3.C. Develop alternative housing for poultry.
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 4 significant areas of concern: aggression, lameness, pain, and discomfort. This unit is charged with the difficult task of conducting research for three species: dairy cattle, swine, and poultry. To accomplish this goal, unit scientists with different expertise work together on multiple and varying projects to address the primary challenges to welfare that are characteristic of the production systems for each species. Our ultimate goal is to: 1) discover and further refine objective measures of stress, and 2) evaluate and create appropriate management and housing methods. A sustained effort is required to make significant progress in optimizing animal welfare.
Calf Group Housing: We sought to determine if distance/placement of bottles in a group housing setting would decrease displacements, aggression, and undesired sucking behaviors in neonatal dairy calves. All behavior data collections are complete and under statistical analysis. Chronic Pain in Cows: We sought to determine how intensely cow immunity is affected by flooring and establish possible biomarkers on leukocytes that are associated with flooring. First lactation cell phenotyping and function assays have been completed, analyzed, and will be presented at an international immunology meeting in August. This data demonstrates that the peripheral blood cell population is altered by exposure to concrete flooring. Sensitivity to additional neurochemicals involved in the pain response (substance-P) is also altered by flooring type and by lactation day. The RNA extractions for that lactation are started, which will unveil critical information as to the cross-talk between the immune cells that is altered by the flooring type. Behavioral collection for the first lactation is complete and analysis is in progress. The second lactation data collection is underway. Effects of in utero heat stress on postnatal metabolic heat production in pigs. Four indirect calorimeters were built in order to quantify the additional energy required by pigs exposed to in utero heat stress. We have determined that in utero heat-stressed pigs have a 14.6% increase in fasting metabolic heat production compared to controls during postnatal life. Currently, we are analyzing biological samples in order to determine the mechanism by which this increase is occurring. Lameness in sows. The animal work for this study concluded this year. Initial assessment of lesions in the cartilage indicates that as sows grow older lesions in the cartilage of their joints become bigger. Unfortunately, preliminary results don’t support the hypothesis that restricting energy during the growth phase will allow for healthier cartilage. All sows on study had lesions. More data on behavior of the sows is being analyzed prior to any definitive conclusions can be made. Increasing the floor temperature to increase survivability of piglets. We have successfully designed a floor mat that can rise to the high temperature required by this study as these were not commercially available. Proto-types have been designed and tested with positive results. We are continuing to create more heated floor mats to use in the study this winter when piglets are more likely to become chilled. We plan to conduct 3 repetitions of this study during the winter which will complete this work. Euthanasia of piglets. A box has been designed to deliver two types of gas sequentially to piglets, which was the first phase of this experiment. In addition, the first repetition conducting euthanasia using nitrous oxide while measuring brain activity has been completed. A second repetition will complete this portion of the study in October, prior to moving to the third phase of on-farm application. Tryptophan supplementation during early pregnancy. We have collected data on piglet behavior for more than half of the sows that have been treated. Data is currently being analyzed and a final repetition will be completed this year that will conclude the animal portion of the study, allowing data analysis to be completed during the next fiscal year. Decreasing the floor temperature of the farrowing stall under the sow increases piglet survivability. Initially, fundamental work has focused on cooling pad fabrication, to test construction materials and design of cooling system which maximizes heat removal from an artificial sow model, yet retains durability. The first applied study has field tested our water-cooled prototype pad, investigating 3 water flow rates (low, medium and high) with 35°C room temperatures. All 3 flow rates decrease effects of heat stress on sows and do so in a dose-dependent way. The next phase will investigate the longer-term effects of cooling pads on sow and piglet productivity.
1. Development of a novel procedure to non-invasively measure core body temperature in sows. Measurement of core body temperature is essential in swine research related to heat stress and immune function; however, it is often very labor intensive and manual methods can cause an artificial increase body temperature due to stress. Furthermore, consistently measuring body temperature in group-housed pigs in a natural environment is often difficult. In order to improve the accuracy of core body temperature collection and allow for temperature constant collection of temperature without disturbing animals, ARS researchers in West Lafayette, Indiana developed an implantable vaginal temperature monitor for sows that allow for non-invasive body temperature collection. Researchers were able to validate the use of these data recording devices. These devices have been essential in data collection within the West Lafayette, Indiana ARS location and are currently in use by researchers at two universities, and by swine companies in their in-house research programs.
2. Dam heat stress effects on calves. Heat stress is a problem for dairy cattle and heat abatement practices for non-lactating, pregnant cows is often unavailable. ARS researchers in West Lafayette, Indiana sought to determine the effects of a heat event in late gestation on microbial populations on the cows that may be transmitted to the calves, and on neonatal calf behavior. Cows under heat stress conditions had elevated stress hormones and greater bacteria load (Lactobacilli). Calves from heat stressed cows had reduced rectal bacteria (coliform), but Lactobacilli counts were not different. Respiration rates were greater for calves born to cows that were not heat stressed; while calves from heat stressed cows had more object manipulation and oral behaviors than the calves from the non-heat stressed cows. The recognition that calves born to cows that experienced a heat stress event have altered behavior and physiology provides producers with the information to allow them to better manage these individuals.
3. Effects of rapid temperature fluctuations prior to breeding on reproductive efficiency in pigs. Extreme hot weather events continue to negatively impact global livestock production despite advances in animal management practices, genetics, and nutritional strategies developed to make animals more resistant to hyperthermia. Based on previous observations that rapidly cooling pigs after acute heat stress results in a condition characterized by intestinal damage and an increase in inflammation, researchers at the West Lafayette, Indiana ARS location performed research to determine if this may be one mechanism by which reproductive losses occur during times of rapid temperature fluctuations. As a result of this experiment, researchers determined that rapid cooling during times of acute heat stress can contribute to greater inflammation and insulin resistance, which likely contributed to a reduction in fetal viability in sows. These results can improve how swine producers manage pigs during times of heat stress in order to improve production efficiency and the well-being of agriculturally important livestock species.
4. Perch use by laying hens. Osteoporosis is widespread in today’s commercial laying hens and contributes to approximately 20 to 35% of all mortalities during the egg production cycle of caged hens. Bone fractures during production are a significant welfare concern because of the chronic pain these hens may experience. ARS researchers at West Lafayette, Indiana found that mechanical loading achieved through perching has beneficial effects on pullet health by stimulating leg muscle deposition and increasing the bone mineral content of certain bones without causing a concomitant decrease in bone mineral density. These results show that perch usage will have minimal economic impact to egg producers as perches will only be needed in the pullet cages to enhance skeletal health.
5. Evaluation of the physiological impact of heatstroke recovery practices in a swine model. As a result of climate change, the incidences of extreme hot weather events and hyperthermia can result in morbidity and mortality in both livestock and humans if proper recovery procedures are not implemented. Based on previous observations that rapid cooling procedures increase intestinal temperature in pigs, researchers at the West Lafayette, Indiana ARS location hypothesized that rapid cooling after acute hyperthermia would result in greater intestinal damage and increase illness in pigs. Rapid cooling procedures can directly prevent effective heat dissipation through the skin and this negatively impacts intestinal health resulting in greater inflammation and illness. Increased intestinal damage and inflammation has obvious implications for both human health and animal agriculture and this study expanded our knowledge of how heatstroke recovery methods directly affect both thermal status and mammalian biology. Furthermore, data generated by this project can be used to improve how we manage pigs during times of acute heat stress and potentially help to improve heatstroke recovery practices in humans.
Sapkota, A., Marchant Forde, J.N., Richert, B.T., Lay Jr., D.C. 2016. Including dietary fiber and resistant starch to increase satiety and reduce aggression in gestating sows. Journal of Animal Science. 94:1-11. doi:10.2527/jas2015-0013.
Strong, R.A., Silva, E.B., Cheng, H., Eicher, S.D. 2015. Acute brief heat stress in late gestation alters neonatal calf innate immune functions. Journal of Dairy Science. 98:7771-7783. doi.org/10.3168/jds.2015-9591.
Johnson, J., Sapkota, A., Lay Jr., D.C. 2016. Rapid cooling after acute hyperthermia alters intestinal tissue morphology and increases the systemic inflammatory response in pigs. Journal of Applied Physiology. doi: 10.1152/japplphysiol.00685.2015.
Sapkota, A., Herr, A., Johnson, J., Lay Jr., D.C. 2016. Exposure to thermoneutral conditions following acute heat stress reduces skin temperature and increase core body temperature in pigs. Livestock Science. doi:10.1016/j.livsci.2016.07.010.
Strong, R.A., Hester, P.Y., Eicher, S.D., Hu, J., Cheng, H. 2015. The effect of cooled perches on immunological parameters of caged White Leghorn hens during the hot summer months. PLoS One. 10(10): e0141215. doi:10.1371/journal.pone.0141215.
Hu, J., Hester, P.Y., Makagon, M.M., Vezzoli, G., Gates, R.S., Xiong, Y., Cheng, H. 2016. Cooled perch effects on performance and well-being traits in caged White Leghorn hens. Poultry Science. doi: 10.3382/ps/pew248.
Mahmoud, U.T., Cheng, H., Applegate, T. 2015. Functions of Propolis as a natural feed additive in poultry. World's Poultry Science Journal. 72(01): 37-48. doi: 10.1017/S0043933915002731.
O'Connor, A., Anthony, R., Bergamasco, L., Coetzee, J., Dzikamunhenga, R.S., Johnson, A.K., Karriker, L.A., Marchant Forde, J.N., Martineau, G.S., Millman, S.T., Pajor, E.A., Rutherford, K., Sprague, M., Sutherland, M., Von Borell, E., Webb, S. 2016. Review: Assessment of completeness of reporting in intervention studies using livestock: an example from pain mitigation interventions in neonatal piglets. Animal. 10(4): 660-670. doi: 10.1017/S1751731115002323.