Swine Fertility Under Threat from Rising Temperatures, New Study Reveals

A recent study by Robert V. Knox from the Department of Animal Sciences at the University of Illinois has highlighted the significant impact of climate change on swine fertility, with particular emphasis on the detrimental effects of rising temperatures.

The study “Swine Fertility in a Changing Climate“ explores the relationship between increasing global temperatures and pig fertility. It reveals how certain regions have become more susceptible to environmental hazards that limit pig production. The study discusses the complex physiological changes that pigs undergo due to heat stress, which affects reproductive efficiency.

According to Knox, heat stress is a major factor impacting pig fertility. “Elevated temperatures and an increased number of heat stress days lead to changes in pig physiology, including alterations in body temperature, feed intake, and stress responses,” Knox notes. These changes can significantly affect follicle development, oocyte quality, estrus expression, conception rates, and litter size in sows. Boars are also affected by heat stress, which leads to reduced sperm quality and production.

Different Regions, Different Boars

The research highlights that pigs, particularly those in sub-tropical regions, show lower fertility rates during summer because of prolonged exposure to high temperatures. The ancestral European wild boar, a seasonal breeder, primarily breeds in fall and winter. In contrast, modern domestic pigs, which producers have bred to be productive year-round, face increased fertility issues under similar heat stress conditions.

The study also notes that while some regions, like the Southeastern United States, have experienced progressive temperature increases, others have not. This variation likely results from differing climate conditions or differences in how researchers measure and manage heat stress.

Knox’s study urges the development of environmental measures to assess changes in pig fertility related to heat stress accurately. He suggests that as global temperatures continue to rise, these fertility challenges will likely become more apparent and widespread, potentially threatening the sustainability of pig production in many regions.

As climate change progresses, the need for adaptive strategies in pig management becomes increasingly critical. Farmers and producers should consider implementing measures such as improved cooling systems, better breeding practices, and enhanced animal care techniques to mitigate the effects of heat stress on swine fertility.

This research underscores the importance of addressing climate change’s impact on agriculture and animal husbandry, particularly in regions where pig production is vital to the economy. Knox concludes, “The future of pig fertility depends on our ability to adapt to a changing climate and to develop solutions that ensure sustainable production practices.”