稀土壳糖胺螯合盐对热应激肉鸡生长性能和肉品质的影响

Effects of rare earth-chitosan chelate on the growth performance and meat quality of yellow-feathered broilers under heat stress

关键词:  黄羽肉鸡  稀土壳糖胺螯合盐  热应激  生长性能  肉品质

Key words:  yellow feather broiler  rare earth-chitosan chelate  heat stress  growth performance  meat quality

摘要:

为探究稀土壳糖胺螯合盐（Rare earth-chitosan chelate，RECC）对热应激黄羽肉鸡的生长性能和肉品质的影响。本研究选用1日龄的黄羽肉鸡（90只），按照饲养标准饲养至29日龄时开始热应激，试验持续2周。试验分为3组：即对照组（饲养温度约25℃+基础日粮）、热应激组（饲养温度约37℃+基础日粮）以及稀土组（饲养温度约37℃+基础日粮+0.03% RECC）。在热应激1和2周后，分别计算肉鸡平均日增重、料重比，并分析肉品质的变化。结果表明：热应激1周后，肉鸡平均日采食量各组间均无显著性差异（P>0.05）；而平均日增重的变化是对照组显著高于热应激组（P<0.05）和稀土组（P<0.01），热应激组和稀土组未见显著性差异（P>0.05）；对照组腿肌pH显著高于稀土组（P<0.05）；对照组腿肌剪切力与热应激组和稀土组差异均极显著（P<0.01）。热应激2周后，对照组平均日采食量显著高于热应激组（P<0.05）和稀土组（P<0.01），而热应激组和稀土组之间无显著性差异（P>0.05）；热应激组平均日增重显著低于对照组和稀土组（P<0.05），对照组与稀土组之间未见显著性差异（P>0.05）；各组间腿肌pH和剪切力均无显著差异（P>0.05）；热应激组腿肌持水力显著低于与对照组和稀土组（P<0.01）。热应激1和2周后，对照组胸肌pH、持水力均显著高于热应激组和稀土组（P<0.05）；而剪切力均显著低于热应激组和稀土组（P<0.05）。研究发现，随着热应激时间的延长，RECC可改善热应激对肉鸡日增重的影响，提高饲料利用率，缓解热应激对肌肉持水力损害，改善肉品质。

Abstract:

To investigate the effects of rare earth-chitosan chelate (RECC) on growth performance and meat quality of yellow-feathered broilers under heat stress.Ninety one-day-old yellow-feathered broilers were selected for heat stress test at 29-day-old,and the trial lasted for 2 weeks.The broilers were randomly divided into three groups at 29 day:the control group (feeding temperature about 25℃ + basic diet),the heat stress group (feeding temperature about 37℃ + basic diet) and the rare earth group (feeding temperature about 37℃ + basic diet + 0.03% RECC).After 1 and 2 weeks of heat stress,the ratio of average daily food intake and weight gain of broiler were calculated,and the changes of meat quality were analyzed.The results showed:after 1 week of heat stress,the average daily food intake displayed no significant difference among three groups (P>0.05);the average daily gain in the control group was significantly higher than those of the heat stress group (P<0.05) and the rare earth group (P<0.01),while there was no significant difference between the heat stress group and the rare earth group (P>0.05);The leg muscle pH of the control group was significantly higher than that of the rare earth group (P<0.05),and the shear force of the leg muscle in the control group was significantly different from the heat stress group and the rare earth group (P<0.01).After 2 weeks of heat stress,the average daily food intake of the control group was significantly higher than those of the heat stress group and the rare earth group (P<0.01),while the average daily food intake showed no significant difference between the heat stress group and the rare earth group (P>0.05);the daily gain in heat stress group was significantly lower than the control group and the rare earth group (P<0.05),but there was no significant difference between the control group and the rare earth group (P>0.05);there was no significant difference in the pH and the shear force of leg muscle between different groups (P>0.05);the leg muscle water holding capacity in the heat stress group was significantly lower than the control group and the rare earth group (P<0.01).After 1 and 2 weeks of heat stress,the chest muscle pH and chest muscle water holding capacity of the control group was significantly higher (P<0.05) than those of other two groups (P<0.05);while the shear force was significantly lower than those of other two groups.In conclusion,under the continuous heat stress,RECC could effectively relief the impacts of heat stress on the daily gain,improve feed utilization rate and alleviate the damage of heat stress on the muscle water holding capacity and therefore maintain meat quality.