Date Full Report Received


Date Abstract Report Received


In utero heat stress negatively impacts swine health and productivity throughout their entire lifespan. Negative effects range from decreased growth performance and meat quality to reduced reproductive efficiency and greater stress and disease susceptibility. The decrease in growth performance and increased stress response of in utero heat-stressed pigs may be partially due to increased energy requirements compared to in utero thermoneutral counterparts. Therefore, the experimental objective was to determine whether providing newly weaned and transported in utero heat-stressed pigs with higher energy nutrient dense diets would improve growth performance and decrease stress during the nursery phase of growth. We determined that increasing the energy content of the diet did not improve growth performance of the in utero heat-stressed pigs as average daily body weight gain was reduced overall when compared to in utero thermoneutral controls. This response was likely due to the fact that pigs provided the nutrient dense diet voluntarily reduced their feed intake so that total energy consumed was similar to that of the control diet fed pigs. The decrease in body weight gain for the in utero heat-stressed pigs was accompanied by metabolic alterations that prevented them from mobilizing energy reserves following weaning and transport when compared to in utero thermoneutral pigs. Overall, these data indicate that in utero heat stress is detrimental to future pig growth performance and health, especially during times of increased stress such as weaning and transport. Furthermore, the negative impact on growth performance is not rescued by the provision of more nutrient dense diets.