饲粮维生素A水平对肉鸡屠宰性能及肉品质的影响

试验研究了饲粮不同水平维生素A对肉鸡屠宰性能、肌肉肉品质的影响,为通过营养手段改善肉鸡肌肉品质提供参考依据。240只1日龄公、母各半健康爱拔益加(AA)肉鸡,随机分为试验Ⅰ~Ⅴ组(维生素A分别为3 000、6 000、15 000、30 000和45 000 IU/kg),每组6个重复,每个重复8只鸡,试验期42 d。结果表明:胸肌失水率组间差异显著(P=0.004),随维生素A添加水平的升高,胸肌率呈趋于显著的一次线性降低(P=0.10),腿肌率呈显著的二次曲线降低(P=0.04),皮下脂肪厚和胸肌失水率呈显著的一次线性增加(P=0.03,P=0.038),Ⅳ组和Ⅴ组胸肌率和腿肌率较小,皮下脂肪较厚,失水率高;腿肌肉色的a*值组间差异趋于显著(P=0.081),且随日粮维生素A水平升高肉色a*值呈显著的一元二次曲线升高(P=0.049);腿肌pH45 min、剪切力、蒸煮损失随饲粮维生素A添加剂量的增加呈显著的一次线性或二次曲线升高(P=0.003;P=0.015;P=0.043)。在本试验条件下,饲粮维生素A水平为6 000 IU/kg时,肉鸡的肌肉肉品质和屠宰性能较好,30 000~45 000 IU/kg组对肉鸡的屠宰性能和肌肉品质有负面影响。

Effect of dietary vitamin A supplementation on slaughter performance and meat quality of broilers

The experiment mainly studied the effect of dietary supplementation with different levels vitamin A(VA) on slaughter performance and meat quality of broilers. A total of 240 one-day-old healthy AA broilers were randomly allotted into five treatments with six replicates of eight broilers in each group. The trial lasted for forty-two days. Broilers were fed with five levels of dietary VA groupⅠ~Ⅴ(3 000, 6 000, 15 000, 30 000 and 45 000 IU/kg) in a single factorial arrangement. The loss of water of breast muscle were significantly different among diets with different VA(P=0.004). Breast muscle rate and leg muscle rate showed a tend to be significant and significant linearly or quadratically decrease(P=0.10;P=0.04), and subcutaneous fat thickness and water loss rate of breast muscle showed a significant linearly increase with the increase of dietary vitamin A(P=0.03;P=0.038). In the Ⅳ and Ⅴ groups, breast muscle rate and leg muscle rate was lower, subcutaneous fat thickness and water loss rate was higher. The difference in a* of leg muscle among the different VA treatment groups tended to be significant(P=0.081). The meat color a* value of leg muscle increased quadratically(P=0.049), the pH value at 45 min and shear force and cooking loss of leg muscle showed a linear or quadratic increase(P=0.003;P=0.015;P=0.043)with the increase of dietary VA level. In summary, under the experimental condition, the addition of VA at 6 000 IU/kg allowed broilers to have better meat quality and slaughter performance, and 30 000~45 000 IU/kg VA had a negative effect on the slaughter performance and muscle quality of broilers.