β-羟基-β-甲基丁酸对肉仔鸡生长性能和屠宰性能的影响

Effects of beta-hydroxy-beta-methyl butyrate on growth and slaughter performance in broiler chick

选择240只7日龄肉仔鸡按照体重相近原则随机分为5组,每组6个重复,每个重复8只,分别饲喂添加0%、0.01%、0.055%、0.1%、0.145%β-羟基-β-甲基丁酸(HMB)的试验日粮。采用三层笼养,试验期35d。试验结果表明:(1)不同水平HMB对肉仔鸡生产性能的总体影响不显著。7～21日龄时,与对照组相比,0.145%HMB组肉仔鸡料重比降低6.06%(P>0.05);0.1%和0.145%HMB组肉仔鸡死亡率低于对照组水平。22～42日龄时,0.145%HMB组肉仔鸡采食量与对照组相比降低9.94%,各处理组体增重和料重比差异不显著(P>0.05);7～42日龄时,0.145%HMB组肉仔鸡采食量与对照组相比降低9.03%(P<0.05),各处理间体增重和料重比无显著差异,但0.145%HMB组肉鸡料重比最小,0.1%和0.145%HMB组肉仔鸡死亡率低于对照组和其他处理组。(2)肉仔鸡的屠宰性能包括屠宰率、半净膛、全净膛率、胸肌率、腿肌率和腹脂率在各处理间无显著差异(P>0.05),0.145%HMB组肉仔鸡腿肌率较对照组提高3.74%(P=0.075)。可见,在7～42日龄肉仔鸡日粮中添加适量的HMB可显著降低肉仔鸡采食量,而体增重和饲料效率无显著变化,并有促进肉仔鸡腿部肌肉生长发育的趋势。

Two hundred and forty 7-day-old broiler chicks were randomly allotted into 5 groups with different inclusion of beta-hydroxy-beta-methyl butyrate （HMB） （0 % ,0.01% ,0.055 % ,0.1% or 0.145 %）for 5 weeks.Each group consisted of 6 replicates with 8 birds each.The results showed as follows ： （ 1 ）The addition of HMB did not affect the gen- eral performance of chicks.During 7 to 21 d of ages,ratio of feed to gain in chicks fed 0.145 % HMB was decreased by 6.06 % compared to chicks fed control diet.Mortality rate in chicks fed 0.1% and 0.145 % HMB diet were lower than those fed control diet.From 22 to 42 d of ages,feed intake in chicks fed 0.145 % HMB diet was decreased by 9.94 % compared to those fed control diets and no difference was found on ratio of feed to gain among groups.During 7 to 42 d of ages ,feed intake in 0.145 % HMB group was decreased by 9.03 % compared to control group （P 〈 0.05 ）,and the ratio of feed to gain was lowest in chicks fed 0.145 % HMB diet.Chicks fed 0.1% and 0.145 % HMB diet had lower mortality rate than those in other groups. （2）The slaughter performance including dressed carcass percentage,percentages of half-evis- cerated yield,clean chamber ratio,breast muscle,leg muscle and abdominal fat had no significant differences among groups.Chicks fed the 0.145 % HMB diet had 3.74 % elevation in leg muscle ratio than eontrol（P 〉 0.05 ）.The overall results demonstrated that supplementation of appropriate HMB in diet of chicks from 7 to 42 d of ages could decrease the feed intake without adversely affecting body weight gain and feed efficiency ,and had the tendency to improve the growth of leg muscle.