饮水中添加乳酸对三黄鸡生长性能和抗病力的影响

目的研究饮水中添加乳酸对三黄鸡的生长性能和抗病力的影响。方法选取1日龄三黄鸡5 000羽,随机分为5组,1 000只/组。在饮水中加入乳酸调节饮水pH值,使得A组、B组、C组和D组的饮水pH值分别为2.0、3.0、4.0和5.0,每天试验鸡饮用酸化水4 h,对照组为正常饮水组。测定各组试验鸡体重和采食量,并记录每日病死数,计算平均日增重、饲料转化率和病死率。结果①平均日增重：1~35日龄段,C组试验鸡的平均日增重提高最明显,提高3.33%。36日龄后,仅B组和对照组相同水平,其他组均降低。②采食量和饲料转化率：B组、C组与对照组相比差异显著（P<0.05）,A组、D组差异不显著（P>0.05）。③病死率：A组、B组、C组、D组比对照组病死率分别减少3.7%、4.2%、4.7%和2.1%。结论在三黄鸡的饲养试验中,乳酸调节饮水pH值为4.0时能有效提高饲料转化率,明显提高1~35日龄段三黄鸡的平均日增重,明显降低三黄鸡的病死率,对于肉鸡促进生长和抗病力具有良好的应用前景。

Effect of Adding Lactic Acid in Drinking Water on Growth Performance and Disease Resistance of Sanhuang Chickens

Objective] To assess the effect of adding lactic acid in drinking water on the growth performance and disease resistance of Sanhuang chickens. Method] A total of 5 000 one-day-old Sanhuang chickens were selected and randomly divided into 5 groups with 1 000 chickens in each group. Lactic acid was added in drinking water of the four experimental groups of A, B, C and D to adjust the pH value to 2.0, 3.0, 4.0 and 5.0, respectively. The chickens in the experimental groups were given acidified water for 4 hours per day, and the control group received normal drinking water. The body weight and feed intake of the chickens were measured, the number of dead and diseased chickens per day was recorded, and the indicators such as average daily gain, feed conversion rate and mortality rate were calculated. Result] （1） From 1 to 35 days of age, the group C had the most obviously increase in average daily gain which was elevated by 3.33%; after 36 days of age, the group B had the similar level in average daily gain with the control group, while the other experimental groups were reduced. （2）The feed intake and feed conversion rate of the groups B and C had significant （P<0.05） differences compared with the control group, and no significant （P>0.05） differences in those between the groups A and D were observed. （3）The mortality rate of the groups A, B, C and D was reduced by 3.7%, 4.2%, 4.7% and 2.1% compared with the control group, respectively. Conclusion] In the feeding experiment, the feed conversion rate of the Sanhuang chickens is effectively improved when the pH value of drinking water is adjusted to 4.0 by adding lactic acid. Furthermore, the average daily gain of Sanhuang chickens aged 1 to 35 days is obviously increased, and the mortality rate is obviously reduced. It is indicated that adding appropriate level of lactic acid in drinking water has good application prospects in terms of improving growth performance and disease resistance in broilers.