桑叶提取物对AA肉鸡肉品质的影响及其作用机理

Effect of mulberry leaf extract on the meat quality of AA broilers and its mechanism

选用1日龄爱拔益加(AA)肉鸡192羽,随机均分为4组,分别为饲喂基础饲粮的对照组和分别饲喂添加400、800、1200 mg/kg的桑叶提取物的饲粮的3个试验组,分别于1~21日龄和22~42日龄2个阶段测定AA肉鸡的成长性能、血清抗氧化指标、与脂肪代谢相关的生理生化指标及肉鸡肌肉的肉色、pH值、滴水损失率、粗脂肪含量、脂肪酸组成等,探究桑叶提取物对AA肉鸡肉品质的影响及其作用机理。结果表明:与对照相比,饲粮添加桑叶提取物对AA肉鸡的日采食量、料重比、平均日增体质量、体质量、肌肉pH均无显著影响,可极显著或显著降低42日龄肉鸡的胸肌粗脂肪含量和饱和脂肪酸总量的占比及腿肌粗脂肪含量,显著或极显著提高42日龄肉鸡胸肌的二十碳二烯酸、二十碳三烯酸、二十碳四烯酸、二十二碳六烯酸、多不饱和脂肪酸总量的占比及21日龄肉鸡血清的谷胱甘肽过氧化物酶(GSH–Px)、过氧化氢酶(CAT)活性;饲粮添加800 mg/kg桑叶提取物还可显著或极显著降低42日龄肉鸡胸肌的24 h滴水损失率和二十四碳酸占比及21日龄肉鸡腿肌、胸肌的粗脂肪含量与血清中的总胆固醇(TC)浓度,极显著提高42日龄肉鸡腿肌的红度和胸肌的棕榈油酸占比及血清的CAT活性;饲粮添加1200 mg/kg桑叶提取物还可显著或极显著降低21日龄肉鸡腿肌和42日龄时胸肌的24 h滴水损失率,21日龄肉鸡的胸肌和腿肌的粗脂肪含量与血清的MDA含量及42日龄肉鸡胸肌的棕榈酸和二十四碳酸占比与血清的TC浓度,显著或极显著提高21日龄肉鸡血清的T–AOC,42日龄肉鸡腿肌的红度与胸肌的黄度、棕榈油酸、油酸和单不饱和脂肪酸总量的占比及血清的CAT活性和HDL–C浓度。可见,从降低脂肪含量和改善肉品质方面来看,桑叶提取物添加剂量以不低于800 mg/kg为宜。

In this study,192 one-day-old Aiba Yijia(AA)broilers were randomly and equally divided into four groups including a control group fed with basic diet and three experimental groups fed with a diet supplemented with 400,800 and 1200 mg/kg mulberry leaf extract.At the two stages of 1-21-days-old and 22-42-days-old,the growth performance,serum antioxidant indexes,physiological and biochemical indexes related to fat metabolism,meat color,pH value,drip loss rate,crude fat content and fatty acid composition of AA broilers were measured respectively to investigate the effect of mulberry leaf extract on the meat quality of AA Broilers and its mechanism how the extract affect the meat quality.The results showed that compared with the control,the leaf extract treatments had no significant effect on the daily feed intake,feed to weight ratio,average daily gain,body weight and muscle pH of AA broilers;while could extremely significantly or significantly reduce the crude fat content and the proportion of total saturated fatty acids of breast muscle,and the crude fat content of leg muscle of 42-days-old broilers;and significantly or extremely significantly increase the proportions of eicosadienoic acid,eicosatrienoic acid,eicosatetraenoic acid,docosahexaenoic acid,total polyunsaturated fatty acids of breast muscle of 42-days-old broilers and the activities of glutathione peroxidase(GSH-PX)and catalase(CAT)in serum of 21-days-old broilers.The diet supplemented with 800 mg/kg mulberry leaf extract could significantly or extremely significantly reduce the 24-hour drip loss rate and the proportion of 24-carbonic acid in the breast muscle of 42-days-old broilers,and the crude fat content in the leg muscle and breast muscle and the total cholesterol(TC)concentration in the serum of 21-days-old broilers;and extremely significantly improve the redness of the leg muscle,the proportion of palmitoleic acid in the breast muscle and the CAT activity in the serum of 42-days-old broilers.The diet supplemented with 1200 mg/kg mulberry leaf extract could also significantly or extremely significantly reduce the 24-hour drip loss rate of the leg muscle of 21-days-old broilers and the breast muscle of 42-days-old broilers,the crude fat contents of breast and leg muscle and the serum MDA content of 21-days-old broilers,as well as the proportions of palmitic acid and 24-carbonic acid of the breast muscle and the serum TC concentration of 42-days-old broilers;significantly or extremely significantly improve the serum T-AOC of 21-days-old broilers,and the redness of leg muscle and the yellowness and the proportions of palmitoleic acid,oleic acid and total monounsaturated fatty acid of breast muscle,and the serum CAT activity and HDL-C concentration of 42-days-old broilers.Taken together,by using the way,reducing the fat to improve meat quality,it was favor of adding mulberry leaf extract at a dosage of no less than 800 mg/kg.