乳酸锌对断奶肉兔生长性能、肠道发育和血清生化指标的影响

本试验旨在研究饲粮中添加乳酸锌对断奶肉兔生长性能、肠道发育和血清生化指标的影响。选择28日龄同期断奶新西兰兔420只,随机分为5组:对照组(饲喂基础饲粮,饲粮中添加硫酸锌形式的锌0 mg/kg)、硫酸锌组(在基础饲粮中添加硫酸锌形式的锌80 mg/kg)以及3个乳酸锌组(在基础饲粮中分别添加乳酸锌形式的锌20、40、80 mg/kg),每组14个重复,每个重复6只(公母各占1/2)。预试期7 d,正试期42 d。结果表明:1)与对照组相比,饲粮中添加40和80 mg/kg乳酸锌可以显著提高断奶肉兔的试验末重和平均日增重(P<0.05),显著降低料重比、腹泻率和死亡率(P<0.05),但对平均日采食量无显著影响(P>0.05);40 mg/kg乳酸锌组肉兔的试验末重、平均日增重和料重比与硫酸锌组差异不显著(P>0.05),但腹泻率和死亡率较低。2)与对照组相比,饲粮中添加40和80 mg/kg乳酸锌可以显著提高断奶肉兔小肠绒毛高度和绒毛高度/隐窝深度(P<0.05),显著降低十二指肠隐窝深度(P<0.05);80 mg/kg乳酸锌组肉兔十二指肠绒毛高度显著高于同水平硫酸锌组(P<0.05)。3)与对照组相比,饲粮中添加40和80 mg/kg乳酸锌可以显著提高断奶肉兔血清抗氧化酶活性及生长激素和胰岛素样生长因子-Ⅰ含量(P<0.05);40 mg/kg乳酸锌组肉兔血清生化指标与硫酸锌组差异不显著(P>0.05),80 mg/kg乳酸锌组在提高肉兔血清铜锌超氧化物歧化酶活性和生长激素含量方面优于同水平硫酸锌组。综上所述,饲粮中添加乳酸锌可以促进肉兔生长、降低腹泻率和死亡率、改善血清生化指标和肠道发育;乳酸锌的添加效果显著优于相同水平的硫酸锌,养兔生产中乳酸锌适宜添加水平为40 mg/kg。

Effects of Zinc Lactate on Growth Performance,Intestinal Development and Serum Biochemical Indexes of Weaned Rabbits

The purpose of this experiment was to study the effects of zinc lactate on growth performance,intestinal development and serum biochemical indexes of weaned rabbits.In the experiment,420 weaned New Zealand rabbits at 28 days of age were randomly divided into 5 group:control group(fed a basal diet supplemented with 0 mg/kg zinc sulfate),zinc sulfate group(fed the basal diet supplemented with 80 mg/kg zinc sulfate)and three zinc lactate groups(fed the basal diet supplemented with 20,40 and 80 mg/kg zinc lactate,respectively),and each group had 14 replicates with 6 rabbits(half male and half female)per replicate.The pre-experimental period lasted for 7 days,and the experimental period lasted for 42 days.The results showed as follows:1)compared with control group,the diet supplemented with 40 and 80 mg/kg zinc lactate significantly increased the final body weight and average daily gain of weaned rabbits(P<0.05),decreased the feed to weight ratio,diarrhea rate and mortality(P<0.05),but had no significant effect on the average daily intake(P>0.05);the final body weight,average daily gain and feed to weight ratio of 40 mg/kg zinc lactate group was not different from zinc sulfate group(P>0.05),but diarrhea rate and mortality were lower.2)Compared with control group,adding 40 and 80 mg/kg zinc lactate to the diet could significantly increase the villus height and villus height/crypt depth of small intestine(P<0.05),and significantly decrease the depth of duodenal crypt(P<0.05);the height of duodenal villus in 80 mg/kg zinc lactate group was significantly higher than that in the same level zinc sulfate group(P<0.05).3)Compared with control group,adding 40 and 80 mg/kg zinc lactate to the diet could significantly improve the serum antioxidant enzyme activity,growth hormone and insulin-like growth factor-Ⅰcontents of weaned rabbits(P<0.05);the serum biochemical indexes in 40 mg/kg zinc lactate group were not different from those in zinc sulfate group(P>0.05),and 80 mg/kg zinc lactate group was superior to the same level zinc sulfate group in improving the serum copper zinc superoxide dismutase activity and growth hormone content of weaned rabbits.Therefore,zinc lactate added to the diet can promote the growth of meat rabbits,reduce the diarrhea rate and mortality rate,improve serum biochemical indexes and intestinal development;the effects of zinc lactate added is significantly better than that of zinc sulfate at the same level,and the appropriate amounts of zinc lactate in diet is 40 mg/kg in rabbit production.