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

Jacob R. Tuell,Jacob M. Maskal,Yuan H. Brad Kim,Mariah J. Nondorf,Jay S. Johnson

doi:10.3390/ani11030717

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.

Highlights

Climate change threatens the efficiency and sustainability of pork production systems [1]
Gilts from the in utero heat stress (IUHS) group had lower head and heart weights compared to in utero thermoneutral (IUTN) (p < 0.05)
The results of this study provide evidence of the effects of IUHS exposure during the first half of gestation on carcass and meat quality attributes of the offspring

Summary

Introduction

Climate change threatens the efficiency and sustainability of pork production systems [1]. Exposure of the fetus to maternal hyperthermia, known as in utero heat stress (IUHS), has been demonstrated to influence postnatal phenotype and performance traits of pigs, leading to dissimilar carcass composition when market weight is reached [3]. The commonly observed differences in carcass composition of IUHS pigs include increased backfat thickness [4,5] and lipid accretion at the expense of protein [6], decreased area of the loin muscle [4], and lower weight of the head [7,8]. Differences in performance and carcass composition through IUHS are often attributed to differential energy metabolism, as several studies have observed changes in blood insulin levels and glucose metabolism [4,9,10]. Accelerated anaerobic muscle metabolism in glycolytic muscle types early postmortem is known to contribute to protein denaturation and the pale, soft, and exudative condition of pork, a major quality defect [17,18]

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Discussion

Conclusion