USA: Research aims to develop boars more tolerant of gestational heat stress

In utero heat stress of boars is a significant threat to pork production, and a University of Nebraska–Lincoln reproductive physiologist is leading a research team that aims to develop boars that are more genetically tolerant of gestational heat stress, according to a news release from the university. In the United States, about 6 million sows a year produce a litter after exposure to gestational heat stress, a threat that is increasing with climate change. At an average of 11 animals in a litter, that’s 66 million piglets affected each year in the US alone. Researchers have known for decades that direct exposure to summer heat stress dramatically impairs sperm production in adult males. In addition, new evidence demonstrates that exposure to in utero heat stress, or IUHS, also impairs boar sperm production, decreasing counts by about 24% and increasing the proportion of abnormal sperm by about 42%. That renders the semen poor quality, said Amy Desaulniers, assistant professor of ...