Heat stress: influence on the physiology, productive and reproductive performance of the pig

Heat stress (HS) compromises reproductive and growth parameters. Pigs subjected to heat stress reduce voluntary intake and modify their energy metabolism causing a reduction in daily weight gain and an increase in subcutaneous fat accumulation, which negatively affects the carcass quality of fattening pigs. In the sow it causes a negative energy balance affecting reproductive performance by increasing the post-weaning estrus interval, decreasing gestation rate, farrowing rate and litter size and weight at birth and weaning. Many of the negative consequences of CE appear to be mediated by hyperpermeability of the intestinal barrier, causing physiological changes such as nutrient partitioning to an activated immune system and adverse effects on the ovaries through elevated endotoxin and insulin signaling, resulting in failure of the sow's reproductive function.