Impacts of in Utero Heat Stress on Carcass and Meat Quality Traits of Market Weight Gilts

Abstract

This study evaluated the impacts of in utero heat stress (IUHS) on the carcass and meat quality traits of offspring when market weight was reached. Twenty-four F1 Landrace × Large White gilts were blocked by body weight and allocated among thermoneutral (IUTN) or IUHS treatments from d 6 to d 59 of gestation. The offspring were raised under identical thermoneutral conditions, and gilts (n = 10/treatment) at market weight (117.3 ± 1.7 kg) were harvested. At 24 h postmortem, the loins (M. longissimus lumborum) were obtained, and sections were allocated among 1 d and 7 d aging treatments at 2 °C. Carcasses from IUHS pigs had lower head and heart weights (p < 0.05), as well as decreased loin muscle area (p < 0.05) compared to IUTN pigs. Loins from the IUHS group had a higher shear force value than the IUTN group (p < 0.05). Treatments had no other impacts on carcass and meat quality traits (p > 0.05), and Western blots suggested increased toughness of IUHS loins would not be attributed to proteolysis. These results suggest minimizing IUHS during the first half of gestation may be beneficial in improving pork yield and quality, though in general the effects of IUHS would be minimal.

Potential biomarkers for chronic seasonal heat stress in Kagoshima Berkshire pigs reared in the subtropical region

“…Heat stress alters metabolism, structure and antioxidant mechanisms in skeletal muscle (4). Heat exposure of sows during pregnancy affects foetal development and post-growth carcass quality (3,27). In growing pigs, it has been reported that acute heat stress disrupts muscle redox balance and inflammatory signalling (8,21).…”

“…Physiologically, elevations in environmental temperature also directly alter pigs’ nutrient utilisation, energy metabolism, and hormonal regulation ( 5 , 9 , 24 ). Consequently, heat stress can cause substantial economic losses for the swine industry through its effect on growth rates, carcass composition, sow performance, mortality and morbidity ( 2 , 22 , 27 ).…”

Gestational heat stress alters skeletal muscle gene expression profiles and vascularity in fetal pigs in a sexually dimorphic manner

“…Although fat deposition in fetal/newborn piglets is relatively low, it can be detected in fetal skeletal muscles at mid-gestation [47]. Upregulation of adipogenic transcription factors at early developmental stages potentially programs fetal muscle growth and affects carcass traits of the offspring born to sows experiencing HS during early-mid gestation [10][11][12].…”

“…Controlled climate experiments have shown that gestational HS causes lasting effects on the progeny, with reductions in muscle accretion and increased adiposity observed at the finishing stage [9]. Furthermore, sow HS during the first half of gestation contributed to increased subcutaneous fat thickness [10] and decreased loin muscle area in the offspring [11]. A recent study showed that piglets born to sows mated and gestated during summer were lighter at birth, while the carcasses of those born-light progeny tended to deposit less lean and more fat tissue in the loin [12].…”