商品蛋鸡低能量日粮苏氨酸适宜需要量研究

Optimal Threonine Requirement of Low-energy Diet for Commercial Laying Hens

本试验旨在探讨低能量日粮不同苏氨酸水平对产蛋高峰期海兰褐壳蛋鸡生产性能和蛋品质的影响,确定蛋鸡低能量日粮中苏氨酸的适宜水平。试验选取产蛋高峰期的海兰褐壳蛋鸡600只,随机分为5个处理,每个处理5个重复,每个重复24只鸡。采用玉米-花生粕型日粮,代谢能水平为10.89MJ/kg,苏氨酸共设5个水平,分别为：0.45%、0.50%、0.55%、0.60%、0.65%。结果表明：①低能量日粮不同苏氨酸水平对产蛋率、产蛋量有显著影响（P〈0.05）。其中,产蛋率0.60%水平组显著高于0.50%组（P〈0.05）,其它各处理组间差异均不显著（P〉0.05）;产蛋量0.45%组和0.60%组显著高于0.50%组（P〈0.05）,其它各处理组间差异均不显著（P〉0.05）。②低能量日粮不同苏氨酸水平对采食量、蛋重、料蛋比、破蛋率和日增重无显著影响（P〉0.05）。③每产100kg鸡蛋所需的饲料成本0.45%组最低,经济效益最好。④低能量日粮苏氨酸水平在0.45%~0.65%试验范围内变化时,不会对鸡蛋蛋品质产生影响。综合考虑,蛋鸡低能量日粮中苏氨酸的适宜水平为0.45%,或总苏氨酸需要量为547mg/只·d。

This study was conducted to evaluate the effect of different threonine levels of low-energy diet on production performance of Hy-Line brown commercial laying hens, and to determine the optimal threonine level of low-energy diet. Six hundred Hy-Line brown hens were randomly divided into five groups with five replicates per group and 24 hens per replicate. The basal diet was corn-peanut meal and metabolizable energy level was 10.89 MJ/kg and there were five different levels （0.45%,0.50%,0.55%,0.60%,0.65%）. The results showed that different threonine levels of low-energy diet had significant effects on egg production rate and egg mass （P〈0.05）. 0.60% group was significantly higher than 0.50% group （P〈0.05）, but there was no significant difference among the other groups for egg production rate（P〉0.05）. Both 0.45% and 0.60% group were significantly higher than 0.50% group （P〈0.05）, but there was no significant difference among the other groups for egg mass （P〉0.05）. Different threonine levels of low-energy diet had no significant effects on feed intake,egg weight, feed consumed/egg mass,egg hroken ratio and daily gain （P〉0.05）. 0.45% group had the lowest feed cost of all groups for producing 100 kg eggs and it had the best economic benefit. Threonine levels of low-energy diet,ranging from 0.45% to 0.65%,had no significant effects on egg quality （P〉0.05）. Taking the above results into consideration, 0.45% threonine level was adequate for Hy-Line brown hens in the peak period when the metabolizable energy was 10.89 MJ/kg, or total threonine requirement was 547 mg/hen . d.