Heat stress in sows and its effects on farrowing duration

Heat stress can have effects throughout the entire reproductive cycle of sows (Lucy & Sanfranski, 2017). When associated with the mother’s gestation period, negative effects such as a smaller number of embryos and shorter gestation duration can be observed in such situations. Furthermore, at the end of pregnancy, heat stress can increase the duration of farrowing and significantly result in an increased number of stillborn piglets.

For example, Munns et al. (2016) evaluated the productive indicators of females at the end of pregnancy which were subjected to conditions of heat stress (maximum of 25 ºC), and females which were housed in an ideal environment (maximum of 20 ºC). The results of this study have shown that the sows under the control treatment had a shorter farrowing period when compared to those under heat stress (412 vs. 580 min).

That prolonged farrowing duration has negative effects on both sows and piglets. Long farrowing can, for example, compromise the piglets’ intake of quality colostrum, since the concentration of immunoglobulins significantly decreases after the first 6 hours of the birth of the first piglet (Adi et al., 2022). For those reasons, providing sows with heat comfort is essential.