Breeding and Genetics Symposium: Resilience of livestock to changing environments

Authors: Cole, John; BORMANN, JENNIFER - Kansas State University; GILL, CLARE - Texas A&M University; KHATIB, HASAN - University Of Wisconsin; KOLTES, JAMES - University Of Arkansas; MALTECCA, CHRISTIAN - North Carolina State University; MILGIOR, FILIPPO - Canadian Dairy Network

Submitted to: Journal of Animal Science
Publication Type: Review Article
Publication Acceptance Date: 1/18/2017
Publication Date: 4/1/2017
Citation: Cole, J.B., Bormann, J.M., Gill, C.A., Khatib, H., Koltes, J., Maltecca, C., Milgior, F. 2017. Breeding and Genetics Symposium: Resilience of livestock to changing environments. Journal of Animal Science. 95(4):1777-1779. https://doi.org/10.2527/jas.2017.1402.
DOI: https://doi.org/10.2527/jas.2017.1402

Interpretive Summary: Modern livestock have been selected to efficiently convert feed into food and fiber for human use, but the most productive breeds generally require intensive management in order to maintain high levels of production. Most major livestock breeds in the US are derived from animals that evolved in temperate climates, such as Holstein dairy cattle. Unfortunately, the climate in the southern states is hot enough to cause several months a year of heat stress. Heat stress occurs when the environmental temperature exceeds an animal’s thermoneutral point, and its effects include decreased dry matter intake, reduced water consumption, depressed production, and impaired fertility. These effects will become more common in areas that have not previously experienced heat stress as global temperatures continue to rise. Technological interventions, including fans, sprinklers, and shade structures, can be used to ameliorate many of the effects of heat stress, but they provide only temporary relief. Genetic selection for greater thermotolerance is possible and will result in cumulative, permanent gains. This symposium was developed for the purpose of providing a comprehensive overview of current knowledge about the effects of hot environments on livestock species, and the speakers did an excellent job of doing that. Specific, actionable recommendations were made that can be addressed using existing tools, and important research questions that may lead to new tools were raised. Changing environments will force livestock and aquaculture producers and researchers to develop innovative solutions to adapt to those changes, and to continue providing high-quality, affordable food and fiber to a growing human population.

Technical Abstract: The Breeding and Genetics Symposium titled “Resilience of Livestock to Changing Environments” was held at the Joint Annual Meeting, July 19–24, 2016, Salt Lake City, UT. The objective of the symposium was to provide a broad overview of recent research on the effects of changing environmental conditions on livestock. Topics covered by the speakers included a review of the variation in response to heat stress and its effects on metabolic parameters and energy demands in pigs and cattle, production and reproduction in livestock and aquaculture species, the development of genetic improvement programs to produce more robust animals, and the use of gene introgression to develop heat-resistant animals. Substantial discussion focused on the tradeoffs involved in producing robust, high-producing livestock. Modern livestock have been selected to efficiently convert feed into food and fiber for human use, but the most productive breeds generally require intensive management in order to maintain high levels of production. Most major livestock breeds in the US are derived from animals that evolved in temperate climates, such as Holstein dairy cattle. Unfortunately, the climate in the southern states is hot enough to cause several months a year of heat stress. Heat stress occurs when the environmental temperature exceeds an animal’s thermoneutral point, and its effects include decreased dry matter intake, reduced water consumption, depressed production, and impaired fertility. These effects will become more common in areas that have not previously experienced heat stress as global temperatures continue to rise. Technological interventions, including fans, sprinklers, and shade structures, can be used to ameliorate many of the effects of heat stress, but they provide only temporary relief. Genetic selection for greater thermotolerance is possible and will result in cumulative, permanent gains. This Breeding and Genetics symposium was developed for the purpose of providing a comprehensive overview of current knowledge about the effects of hot environments on livestock species, and the speakers did an excellent job of doing that. Specific, actionable recommendations were made that can be addressed using existing tools, and important research questions that may lead to new tools were raised. Changing environments will force livestock and aquaculture producers and researchers to develop innovative solutions to adapt to those changes, and to continue providing high-quality, affordable food and fiber to a growing human population.