热应激对肉仔鸡肉品质及抗氧化能力的影响

Effects of heat stress on meat quality and antioxidant capacity of broilers

为探讨热应激对AA肉仔鸡肉品质及抗氧化能力的影响,试验选用35日龄体重相近的健康AA肉仔鸡(公)120只,随机分成2组,一组高温组(34℃),一组为适温组(21℃),每组5个重复,每个重复12只。试验期为7d。结果表明:高温应激组胸肌和腿肌pH值显著低于适温对照组(P<0.05),滴水损失显著高于适温对照组(P<0.05),但两试验组间剪切力无显著差异(P>0.05)。高温应激组胸肌超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性均低于对照组,且差异显著(P<0.05);GSH-Px活性两试验组间无显著差异(P>0.05)。同时与对照组比较,高温可显著降低腿肌SOD、CAT和GSH-Px活性(P<0.05)。高温应激组胸肌和腿肌MDA水平显著高于对照组(P<0.05)。由此可见,热应激可使AA肉鸡肉品质下降,肌肉氧化程度增加,抗氧化能力降低。

The study was conducted to examine the effect of heat stress on meat quality and antioxidant capacity of AA broiler.A total of 120 35-d-old male AA broiler were allocated to two groups with 5 replicates of 12 each：constant heat stress at 34 ℃ with ad libitum feeding（34 AL）,constant optimal ambient temperature at 21 ℃ with ab libitum feeding （21 AL）.The experiment period was 7 d.The results showed that：compared with the control group,the pH of breast muscle and thigh muscle in stress group in high temperature decreased significantly （P 〈 0.05）,the drip loss increased signifi- cantly（P 〈 0.05 ）.However,there were significant differences of shear force of breast muscle and thigh muscle between the two groups（P 〉 0.05）.In breast muscle,the SOD activity and CAT activity were significantly decreased （P 〈 0.05）by best exposure while GSH-Px activity was not changed（P 〉 0.05）compared to the control group（P 〈 0.05）.In thigh muscle,the SOD activity,CAT activity and GSH-Px activity all significantly decreased in heat stressed group compared to control group.Both in breast muscle and in thigh muscle, the concentration of MDA was significantly increased in heat stress group compared to control group （P 〈 0.05 ）.The results indicated that heat stress treatment could make the meat quality of AA broiler chickens decline, muscle oxidative degree increase, and antioxidant capacity decrease.