Progress 07/31/12 to 09/30/14
Outputs
Progress Report Objectives (from AD-416): For growing meat animals, identify physiological responses to stress that contribute to production loss and disease susceptibility; develop environmental and animal-specific risk assessments of stress as management guides to alert producers and improve animal well-being; develop precision animal management strategies to ameliorate heat stress effects; and develop ventilation design standards for contemporary swine production systems. Approach (from AD-416): This project incorporates components of two former research projects on management of livestock stress and genetic factors related to disease susceptibility. Stress response evaluation utilizes physiological (respiration rate, health status, etc.), physical (body temperature, coat color, etc.), and behavioral (temperament, eating, etc.) measurements to characterize the impact of stress (particularly environmental) on feedlot cattle. These measurements will be refined to provide dynamic response evaluations in a feedlot setting, both for data collection and as potential management tools. The results will provide risk assessment models to assist producers in identification of animals that would most benefit from changes in management (shade, sprinklers, etc.). In addition, weather data will be utilized to provide advanced warnings to producers of impending environmentally stressful conditions to cattle. Genetic diversity for stress traits among several breeds will be characterized to identify breed differences and suggest management alternatives based on genotype. Also, criteria of ventilation requirements for swine production will be updated for modern lean high growth rate animals and ration formulations. Livestock will be observed in production feedlot settings or in controlled environment chambers to provide suitable environmental and management control. The feedlot includes modern animal handling facilities to individually manage cattle or provide group penning of cattle with or without shade. Environmental chambers provide precision control of environmental factors (temperature, humidity, and light) in close proximity of calorimeter equipment to measure energy expenditure of livestock. The availability of a wide range of cattle breeds, extensive animal handling and technical expertise, and animal health practitioners provides the necessary resources for conducting basic and applied research. This is a final report for a bridging project #5438-32630-006-00D. This plan is in the process of being merged with project #5438-31000-092-00D. Management of swine using feeding behavior. During this bridging project, feeding behavior was investigated as a means to manage large groups of finishing pigs. Feeding behavior and time spent eating contain valuable information that can be used for managing livestock, identifying sick animals, and determining genetic differences within a herd. A feeder system, for use in a commercial-sized pen, was designed to record individual animal presence at the feeder; thus, recording feeding behavior. The system recorded information using radio-frequency identification (RFID) technology and a series of multiplexers. It was determined that finishing pigs increase the time spent at the feeder from the day the pigs enter the facility until plateauing approximately 40 days later. The initial manuscript demonstrates the potential of utilizing feeding behavior or time spent eating as a method of managing animals. This work is being continued in a series of experiments to investigate different aspects of feeding behavior. Two experiments were initiated this fiscal year: one experiment was completed to investigate changes in feeding behavior with the different sexes, and the other to investigate the changes in feeding behavior associated with temperature. The first experiment was completed by using a total of 240 pigs (mix of barrows and gilts) at approximately 8 weeks of age, assigned to six pens (5.5 m x 6.0 m) (40 pigs/pen) with equal distribution of age and genders in all pens. Each pig was ear-tagged with a half-duplex, low frequency, passive electronic identification (EID) tag prior to pen placement. This experiment was conducted for a 16-week period. During the study, pigs had ad libitum access to feed and water. The feeders used in this study had been equipped with a feeding behavior monitoring system (Brown-Brandl and Eigenberg, 2011). Feeding activity data was collected continuously on each individual pig throughout the study and summarized for each 24- hour interval. This study was concluded in late spring. The second study was initiated in late spring and will conclude in early fall. This study was conducted in a very similar fashion, 240 pigs (mix of barrows and gilts), were distributed in one of six pens with an equal distribution of weights and genders. Each pig was ear-tagged with a half- duplex, low frequency, passive EID tag prior to pen placement. Two different points in the barn were monitored for temperature and humidity. (Objective 1) Thermal images provide insight into thermal tolerance. During the previous project and this bridging project, heat production from modern pigs was determined to be significantly higher than previously reported. The increase in heat production changes the thermal needs of modern growing pigs. A study was designed to evaluate using surface temperature as a method of determining heat tolerance of growing pigs based on changes in thermal images captured at different temperatures. Both individual animals and groups of animals were used in the analysis. Surface temperatures were significantly affected by ambient temperature and response equations were developed. Breakpoint analysis revealed a threshold, thought to equate to the maximum value of the thermal neutral zone, ranging between 17.4 and 23.2�C. It was concluded that thermal images could be successfully used to evaluate the thermal needs of pigs, and that further experiments need be conducted to validate thresholds as determined by thermal images. To continue this work, an experiment was completed to evaluate three different production phases (nursery, growing, and finishing) of pigs from three commercial sire lines (Landrace, Yorkshire, and Duroc). (Objective 1) Beef Cattle Heat Stress Forecast. A heat stress prediction model has been developed to summarize weather factors into a single index value. A feedlot cattle heat stress website utilizes both the prediction model developed by ARS scientists at Clay Center, Nebraska, and NOAA-National Weather Service digital forecast maps. The website�s primary feature is a seven-day graphical forecast of cattle heat stress. Helpful information is included such as impacts of heat stress, cattle and environmental risk factors, guides to recognizing heat stress, and actions to take for minimizing heat stress. The model continues to be evaluated to ensure accurate predictions of stress level. Based on feedback from producers, the website has expanded to include the entire United States. Website usage data indicates that it is being utilized by both large and small producers in many different states. In an effort to make this information more accessible to producers in the field a smart phone app to provide notifications of heat events is being developed. (Objective 1) Shade as a management option for heat stress in feedlots. Shade has a positive effect on reducing stress in feedlot cattle but implementation is limited due to cost and maintenance issues. Different shading materials range in price and effectiveness with each material having its own set of benefits and challenges. Initial instrumentation tests determined that even a minimal shade will offer enough protection to reduce the thermal index one category (emergency to danger�danger to alert). Animal tests using three of the different types of shade (100% shade cloth, 60% shade cloth, and snow fence) were completed during the summer of 2010; initial analysis of the 2010 data showed that all materials were effective in reducing respiration rates. With this information, a shade structure was designed and built for commercial sized pens. This structure is currently being tested for durability and effectiveness. (Objective 1) Development of an individual responsiveness to heat stress assessment. Animal performance can be reduced and well being compromised during periods of hot weather. Impacts of excess heat load are varied, ranging from little or no effect to death of vulnerable animals during an extreme heat event. Factors that define heat stress have been identified and research undertaken in areas of: environmental conditions, individual animal susceptibility, and management schemes. The ultimate goal is to determine the most appropriate management scheme for each susceptibility level of animals during a variety of summertime conditions. An analysis was developed and completed to assess individual animal responsiveness to heat stress. Responsiveness was modeled by finding the slope of respiration rate with temperature. This analysis revealed the varied responses from cattle with different coat colors and cattle with and without access to shade. It was determined that color/breed plays an important role in heat stress, but there was still a distribution of slopes in all colors/breeds, and not all colors of cattle benefit from having access to shade. Currently different models of responsiveness are being evaluated. (Objective 1) Accomplishments 01 Heat and moisture production using current animal genetics and management procedures were found to be higher than current published standards. Heat and moisture production estimates are critical information for sizing ventilation equipment like heaters and fans in building swine housing. The current estimates are based on measurements that were made 30 to 50 years ago. Modern swine, which are more lean, and modern feeding programs have caused changes in both heat and moisture production of swine. ARS researchers at Clay Center, Nebraska, conducted a series of 10 studies to measure heat and moisture production of the animals and the facilities. The studies were completed at temperatures ranging from normal to hot conditions. Generally, they found the heat production and feed intake decreased and moisture production increased as temperature increases. Overall, heat production was found to be 16% higher than currently published standards, the largest differences were in finishing pigs. Additional research was conducted to determine heat and moisture production in gestating gilts and farrowing sows.
Impacts
(N/A)
Publications
- Brown-Brandl, T.M., Hayes, M., Xin, H., Nienaber, J.A., Li, H., Eigenberg, R.A., Stinn, J.P., Shepherd, T.A. 2014. Heat and moisture production of modern swine. Transactions of the American Society of Heating, Refrigeration, and Air-Conditioning Engineers (ASHRAE). 120(1):469-489.
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Progress 10/01/12 to 09/30/13
Outputs
Progress Report Objectives (from AD-416): For growing meat animals, identify physiological responses to stress that contribute to production loss and disease susceptibility; develop environmental and animal-specific risk assessments of stress as management guides to alert producers and improve animal well-being; develop precision animal management strategies to ameliorate heat stress effects; and develop ventilation design standards for contemporary swine production systems. Approach (from AD-416): This project incorporates components of two former research projects on management of livestock stress and genetic factors related to disease susceptibility. Stress response evaluation utilizes physiological (respiration rate, health status, etc.), physical (body temperature, coat color, etc.), and behavioral (temperament, eating, etc.) measurements to characterize the impact of stress (particularly environmental) on feedlot cattle. These measurements will be refined to provide dynamic response evaluations in a feedlot setting, both for data collection and as potential management tools. The results will provide risk assessment models to assist producers in identification of animals that would most benefit from changes in management (shade, sprinklers, etc.). In addition, weather data will be utilized to provide advanced warnings to producers of impending environmentally stressful conditions to cattle. Genetic diversity for stress traits among several breeds will be characterized to identify breed differences and suggest management alternatives based on genotype. Also, criteria of ventilation requirements for swine production will be updated for modern lean high growth rate animals and ration formulations. Livestock will be observed in production feedlot settings or in controlled environment chambers to provide suitable environmental and management control. The feedlot includes modern animal handling facilities to individually manage cattle or provide group penning of cattle with or without shade. Environmental chambers provide precision control of environmental factors (temperature, humidity, and light) in close proximity of calorimeter equipment to measure energy expenditure of livestock. The availability of a wide range of cattle breeds, extensive animal handling and technical expertise, and animal health practitioners provides the necessary resources for conducting basic and applied research. Bridging project #5438-32630-006-00D was put in place after 5438-32630- 005-00D expired in FY 2012. The new replacement project plan is scheduled for OSQR peer review in June 2014. A feeding system for use in a commercial-sized pen, was designed to record individual animal�s presence at the feeder. The system recorded information using radio-frequency identification (RFID) technology and a series of multiplexers. It was determined that finishing pigs increase the time spent at the feeder from the day the pigs enter the facility until plateauing at approximately day 40. This individual animal data has shown not only differences in feeding behavior between barrows and gilts and fast growing and slow growing animals, but most importantly has shown promise in detecting sick animals. While more work needs to be completed, this initial research demonstrates the potential of utilizing feeding behavior or time spent eating as a method of animal management. A study to evaluate using surface temperatures of swine as a method of determining heat tolerance was completed. Both individual and groups of animals were used in the analysis. Surface temperatures were significantly affected by ambient temperature and response equations were developed. Breakpoint analysis revealed a threshold, thought to equate to the maximum value of the thermal neutral zone, ranging between 17.4�C and 23.2�C. It was concluded that thermal images could be successfully used to evaluate the thermal needs of pigs and further experiments need to be conducted to validate thresholds. Based on previously conducted and reported research, a shade structure was designed and built for commercial sized pens. This structure is currently being tested for durability and effectiveness as a management option for heat stress in feedlots. An analysis was developed and completed to assess individual animal responsiveness, based on breathing rate, to heat stress. This analysis revealed the varied responses from cattle with different coat colors and cattle with and without access to shade. It was determined that color/ breed plays an important role in heat stress, but not all colors/breeds of cattle benefit from having access to shade. Further studies need to be completed to investigate the use of this analysis method with different stress measurements. Accomplishments 01 Development of a new shade structure for commercial sized lots. Shade has a positive effect on reducing stress in feedlot cattle but implementation is limited due to cost and maintenance issues. Different shading materials range in price and effectiveness with each material having its own set of benefits and challenges. Initial instrumentation tests conducted by ARS researchers at Clay Center, NE, determined that even a minimal shade will offer enough protection to reduce the thermal index one category (emergency to danger�danger to alert). Animal tests using 3 of the different types of shade (100% shade cloth, 60% shade cloth, and snow fence) were completed during the summer of 2010. Initial analysis showed that all material were effective in reducing respiration rates and associated heat stress. A shade structure was designed according to the following criteria: cost, effectiveness, durability, low maintenance, and minimal interference with normal feedlot management. The design integrates animal/shade response data collected over the last decade. Eight 10 m tall by 15.4 m long structures were installed at the USMARC feedlot in Clay Center, Nebraska. The north/south structures were fitted with four 15.4 m lengths of poly snow-fence. These structures provide an effective 50% shade coverage that tracks the sun during the day and offers up to 3 m2 of shade per head.
Impacts
(N/A)
Publications
- Brown Brandl, T.M., Rohrer, G.A., Eigenberg, R.A. 2013. Analysis of feeding behavior of group housed growing-finishing pigs. Computers and Electronics in Agriculture. 96:246�252. Online available:
- Brown Brandl, T.M. 2013. Managing thermal stress in feedlot cattle: environment, animal susceptibility and management options from a U.S. perspective. In: Aland, A. and Banhazi, T., editors. Livestock Housing: Modern Management to Ensure Optimal Health and Welfare of Farm Animals. Wageningen, The Netherlands: Academic Publishers. Pages 189-208.
- Brown Brandl, T.M., Eigenberg, R.A., Purswell, J.L. 2013. Using thermal imaging as a method of investigating thermal thresholds in finishing pigs. Biosystems Engineering. 114:327-333.
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