The alleviative effects and related mechanisms of taurine supplementation on growth performance and carcass characteristics in broilers exposed to chronic heat stress

Abstract

To investigate the alleviative effects and molecular mechanisms of taurine supplementation on growth performance and carcass characteristics in broilers exposed to chronic heat stress, 144 male Arbor Acres broilers (28 d old) were randomly distributed to positive control (PC, 22°C, basal diet), heat stress (HS, consistent 32°C, basal diet), or heat stress + taurine (HS + T, consistent 32°C, basal diet + 5.00 g/kg taurine) groups, with 6 cages per group and 8 birds per cage. Chronic heat stress significantly decreased body weight, average daily gain, and average daily feed intake, and increased cloacal temperature and feed conversion ratio (FCR, P < 0.05). Though taurine supplementation tended to decrease the FCR in the HS + T group compared with the HS group after 14 d of heat exposure (P = 0.071), there were no significant alleviative effects of taurine supplementation on the increased cloacal temperature and decreased growth performance in chronic heat-stressed broilers (P > 0.05). After 7 and 14 d of heat exposure, taurine supplementation significantly increased the proportion of breast muscle and hormone-sensitive lipase activity in the abdominal fat (P < 0.05), and decreased the mRNA expressions of muscle atrophy F-box protein (MAFbx) and muscle ring-finger protein-1 (MuRF1) in breast muscle compared with the HS group (P < 0.05). After 7 d of heat exposure, taurine supplementation significantly increased serum non-esterified fatty acid concentration (P < 0.05), and decreased the mRNA expressions of acetyl-CoA carboxylase 1c (ACC) and muscular isoform of carnitine palmitoyl transferase 1 (M-CPT1) compared with the HS group (P < 0.05). In addition, the mRNA expressions of M-CPT1 and ribosomal protein S6 kinase, 70 kDa (p70S6K) in the HS + T group were significantly higher than those of the other two groups after 14 d of heat exposure (P < 0.05). In conclusion, taurine supplementation can improve carcass characteristics of chronic heat-stressed broilers by facilitating lipolysis for energy, enhancing protein synthesis, and suppressing protein degradation of the breast muscles.

Effect of phloretin on growth performance, serum biochemical parameters and antioxidant profile in heat-stressed broilers

“…High summer temperatures seriously affect broiler production ( Lu et al., 2019 ; Humam et al., 2019 ). Feeding is an essential life activity to ensure survival and production of animals.…”

Protective Effects and Potential Mechanisms of Dietary Resveratrol Supplementation on the Spleen of Broilers Under Heat Stress

“…The increase in rectal temperature justifies the plausibility of the chronic heat stress model ( 18 ). Similarly, many studies have reported that chronic heat exposure resulted in markedly higher rectal temperatures in the heat stress group of broilers ( 19 , 20 ). Moreover, a previous study showed that diets supplemented with 500 mg/kg of RSV suppressed the increase in rectal temperature caused by cyclic heat stress ( 21 ).…”

Dry Period Heat Stress Impacts Mammary Protein Metabolism in the Subsequent Lactation

“…Although not directly studied in bovine heat stress studies, Phe supplementation in vitro increased the expression of HSP70 mRNA in bovine renal epithelial cells [51], and Phe metabolism assists in the suppression of T-cell immune responses [52]. Similarly, taurine supplementation in chronically heat-stressed poultry has been shown to promote heat shock protein expression and enhance protein synthesis [53,54]. Thus, upregulation of these AAs in circulation might play a role in assisting in the increased immune and heat shock responses associated with heat stress, both during the dry period and during lactation [43,55].…”