Optimizing Growth and Antioxidant Function in Heat-Stressed Broilers with Vitamin C and Betaine Supplementation

Abstract

For broiler’s health, heat stress (HS) poses a significant challenge. This study investigates the potential of vitamin C (VC) and/or betaine (Bet) to enhance growth performance, regulate serum metabolic parameters, and bolster antioxidant function aiming to mitigate the impact of cyclic HS on broilers. Two hundred Ross 308 broilers at 28 days of age were randomly assigned to five groups. The control group, housed at 24 ± 1℃, was fed a basal diet. High-temperature treatment groups, housed at 32 ± 1℃, received a basal diet with 0 (HS group), 250mg/kg VC (HSVC group), 1000mg/kg Bet (HSBe group), and 250mg/kg VC + 1000mg/kg Bet (HSVCBe group). On day 42, assessments were made on growth performance, muscle quality, serum biochemical parameters, and antioxidant function. Results revealed that HS significantly lowered (P < 0.05) average daily feed intake (ADFI), the degree of redness (a*) in pectoral and leg muscles, and serum total superoxide dismutase (T-SOD) level. It also reduced (P < 0.01) average daily gain (ADG), and serum total antioxidant capacity (T-AOC) level, while increasing (P < 0.05) shear force, serum direct bilirubin (D-BIL), uric acid (UA), and malondialdehyde (MDA) levels compared with the control group. Dietary supplementation of VC and Bet, either alone or in combination, significantly decreased shear force and serum UA level, while increasing ADG and the level of T-AOC, and T-SOD in serum antioxidant compared with the HS group (P < 0.05), with the combination yielding the most pronounced effects. In conclusion, the addition of VC and/or Bet to the diet proves effective in enhancing the growth performance of HS-exposed broilers through the positive regulation of serum chemical metabolism parameters and the alleviation of oxidative damage.