京红商品代蛋鸡预产蛋期(17～20周龄)蛋氨酸需要量研究

本试验旨在研究京红商品代蛋鸡预产蛋期(17~20周龄)饲粮蛋氨酸(Met)需要量。选取16周龄末京红商品代蛋鸡750只,随机分为5组,每组5个重复,每个重复30只鸡。各组饲粮Met水平分别为0.20%、0.26%、0.32%、0.38%、0.44%,试验期4周。结果表明:随着饲粮中Met水平的提高,各组试验鸡20周龄末体重(FBW)和平均日增重(ADG)呈线性增加(P0.05),0.44%Met组的FBW和ADG最高;饲粮Met水平可显著影响血清游离Met含量,0.44%Met组血清游离Met含量显著高于0.20%、0.26%和0.32%Met组(P0.05);日粮Met水平显著影响血清尿酸(UA)含量,0.44%和0.38%Met组的血清UA含量显著高于0.20%和0.26%组(P0.05);随着日粮Met水平的提高,血清碱性磷酸酶(ALP)活性线性增加(P0.05),0.44%Met组ALP活性最高,与其他各组差异不显著。在本试验条件下,京红商品代蛋鸡预产蛋期(17~20周龄)Met需要量为0.44%。

Dietary Methionine Requirement of Jinghong Commercial Layers during Pre-laying Period(17～20 wks)

This study was conducted to investigate the dietary methionine(Met) requirement of Jinghong commercial layers during the pre-laying period(17~20 wks). A total of 750 Jinghong commercial layers aged of 17 weeks were randomly divided into 5 groups with 5 replicates per group and 30 hens per replicate. The level of dietary Met in five diets were 0.20%(control group), 0.26%, 0.32%, 0.38% and 0.44% respectively. The feeding trial was lasted for 4 weeks. The results showed that with the increase of dietary Met levels, the final body weight(FBW) of layers aged of 20 weeks and average daily gain(ADG) of birds presented significantly increasing tendency linearly(P <0.05). The FBW and ADG of laying hens in group of 0.44% Met were the biggest in the five groups. Dietary Met levels presented significantly increasing tendency on serum free methionine linearly(P<0.05). Moreover, the level of serum free methionine in group of 0.44% Met was significantly higher than that in groups of 0.20%, 0.26% and 0.32% Met. There were significant influences of dietary Met on serum uric acid levels of laying hens(P <0.05), the level of serum uric acid in group of 0.38% and 0.44% Met was significantly higher than that in groups of 0.20% and 0.26% Met. The layers in group of 0.44% Met had the highest activity of alkaline phosphatase in the five groups. Integrated growth performance and serum biochemical parameters, the requirement of Met of Jinghong commercial layers is 0.44% during the pre-laying period(17~20 weeks) in this study.