Hydroxy Selenomethionine Improves Meat Quality through Optimal Skeletal Metabolism and Functions of Selenoproteins of Pigs under Chronic Heat Stress

Abstract

Chronic heat stress (CHS) induces metabolic changes in skeletal muscle from growth to maintenance that jeopardizes growth performance, carcass traits, and meat quality of pigs. We investigated the protective effect of dietary organic selenium (hydroxy-4-methylselenobutanoic acid, OH-SeMet) on CHS-induced skeletal muscle damages of growing pigs, and the corresponding responses of selenoproteins. A total of 40 ((Landrace × Yorkshire) × Duroc) pigs with an average live weight of 49.64 ± 2.48 kg were used in this 4-week trial. Pigs were randomly allotted to 5 groups: The control group was raised on a basal diet in a thermoneutral environment (22 ± 2 °C); and four CHS groups were raised on a basal diet and supplemented with Se 0.0, 0.2, 0.4, and 0.6 mg/kg as OH-SeMet, respectively, in hyperthermal condition (33 ± 2 °C). CHS resulted in significant decrease of growth performance, carcass traits, and meat quality, which were associated with reduced (p < 0.05) serum alkaline phosphatase (ALP) and total superoxide dismutase (T-SOD) and increased (p < 0.05) serum creatine (CK), sarcous heat shock protein 70 (HSP70), glucokinase (GCK), phosphoenolpyruvate carboxykinase (PEPCK), and malondialdehyde (MDA) contents. Meanwhile, four metabolism-related genes and seven selenoprotein encoding genes were abnormally expressed in skeletal muscle. Dietary OH-SeMet addition partially alleviated the negative impact of CHS on carcass traits and improved meat quality. These improvements were accompanied by the increase in Se deposition, the anti-oxidative capacity of serum and muscle, and protein abundance of GPX1, GPX3, GPX4, and SELENOP. Supplementation with 0.6 mg Se/kg (OH-SeMet) restored the sarcous PEPCK, and 0.4 and 0.6 mg Se/kg (OH-SeMet) restored all abnormally expressed metabolism-related and selenoprotein encoding genes. In summary, dietary supplementation with OH-SeMet beyond Se requirement mitigated CHS-induced depression of carcass traits and meat quality of pigs associated with optimal skeletal metabolism, enhanced antioxidant capacity, and regulation of selenoproteins in skeletal muscle of pigs.

New horizons for selenium in animal nutrition and functional foods

“…(2017) detected a significant increase in the pH of meat 24 h after slaughter after treatment with Se-enriched yeast. Consistent with those observed results, other data have been reported on the opposite role of hydroxy selenomethionine in a postmortem low pH caused by chronic heat stress ( Liu et al., 2021 ). Thus, a Se-enriched diet may be a good nutritional strategy for meat products with longer shelf lives due to the inhibition of microbial reproduction in meat by a low pH.…”

Impact of Heat Stress on Meat Quality and Antioxidant Markers in Iberian Pigs

“…To decrease metabolic heat production, pigs tend to decrease their feed intake, affecting growth and performance parameters [ 8 ]. In addition, persistent heat stress has a great impact on muscle metabolism and may decrease the meat quality of pigs [ 5 , 9 ]. This impact has been associated with increased oxidative reactions and production of reactive oxygen species (ROS) thus disrupting the redox balance that ensures the stability in skeletal muscle and preserve the meat quality [ 10 , 11 ].…”

Hydroxy-Selenomethionine Mitigated Chronic Heat Stress-Induced Porcine Splenic Damage via Activation of Nrf2/Keap1 Signal and Suppression of NFκb and STAT Signal

“…The spleen is the major organ of cellular immunity and humoral immunity [ 7 ]. Currently, the pig CHS model was developed, and the results suggest a connection between that CHS-induced hepatic metabolic disorder and the depressed meat quality of pigs [ 5 , 25 ]. In the present study, we further explore the impact of the CHS on the immunity of pigs using spleen collected from the same pig CHS model and found that pigs placed in prolonged hyperthermia exhibited lower spleen weight and index ( Figure 1 A,B), and the HSP70 protein abundance of splenic tissue was upregulated ( Figure 1 D,E), which implicated varying degrees of splenic damages induced by CHS at tissue and molecular levels.…”

“…Dietary Se supplementation mitigates LPS-induced murine splenic inflammatory response, and several abnormal expressed selenoprotein encoding genes return to normal [ 24 ]. Our previous study indicates that dietary Se supplementation mitigates CHS-induced depression of carcass traits and the meat quality of pigs [ 25 ]. The subsequent question was, therefore, to find whether those protective effects are partly attributed to the enhancement of the antioxidant capacity and immune function.…”