泰和丝毛乌骨鸡早期(0～12周龄)蛋氨酸需要量研究

Study on the Methionine Requirement of Taihe Silky Fowls in Early Stage (0～12 weeks of age)

A grouped feeding trial, nitrogen balance trial and metabolism trial for Taihe silky fowls were conducted to study the effects of dietary methionine levels on performance, nitrogen retention and serum urea nitrogen concentration, and to determine the total and digestible methionine requirements of Taihe silky fowls in early stage. The results showed that: (1)Dietary Met levels had no significant effect on weight gain(WG)(P>0.05), but feed intake(FI), feed conversion rate(FCR) and serum urea nirogen concentration were significantly improved as dietary Met level increased. (2)With the increase of dietary Met levels, nitrogen retention rate of Taihe silky fowls significantly increased, but excess methionine reduced the nitrogen retention. (3)There were significant differences in methionine requirements between male and female Taihe silky fowls,and the methionine requirements of male were higher than that of female Taihe silky fowls at 4～12 weeks of age. The results suggested that during 0～4 weeks the total and digestible methionine requirements of Taihe silky fowls fed on a diet (19.24% crude protein, metabolizable energy 12.26 MJ/kg and 0.26% supplemental methionine) was 0.44% and 0.41% of dietary levels, respectively. During 4～9 weeks, based on a diet(17.37% crude protein, metabolizable energy 12.26 MJ/kg and 0.23% supplemental methionine) the total and digestible methionine requirements of male Taihe silky fowls was 0.35% and 0.33% of dietary levels, respectively, the female’s was 0.31% and 0.30%, respectively.During 9～12 weeks, fed on a diet(17.00% crude protein, metabolizable energy 12.27 MJ/kg and (0.22%) supplemental methionine) the total and digestible methionine requirements of male Taihe silky fowls was 0.26% and 0.25% of dietary levels,respectively, the female’s was 0.24% and 0.23%, respectively.