柠檬酸对生长肉兔生长性能、养分表观消化率、血清抗氧化指标及肉品质的影响

Effects of Citric Acid on Growth Performance,Nutrient Apparent Digestibilities,Serum Antioxidant Indexes and Meat Quality of Growth Meat Rabbits

本试验旨在研究饲粮中添加柠檬酸对生长肉兔生长性能、养分表观消化率、血清抗氧化指标及肉品质的影响。选取35日龄、体重相近的健康断奶伊拉肉兔300只,随机分为5组,每组60个重复,每个重复1只兔。试验设2个对照组,对照1组为空白对照组,对照2组为抗生素对照组(恩拉霉素20 g/t+金霉素300 g/t),3个试验组分别饲喂含0.5%(Ⅰ组)、1.0%(Ⅱ组)、1.5%(Ⅲ组)柠檬酸的试验饲粮。预试期5 d,正试期22 d。结果表明:1)Ⅰ组与对照2组平均日增重均显著高于对照1组(P<0.05),两组间差异不显著(P>0.05);Ⅱ组、Ⅲ组平均日增重与Ⅰ组、2个对照组差异均不显著(P>0.05)。Ⅰ组料重比和对照2组差异不显著(P>0.05),但均显著低于对照1组(P<0.05),各试验组之间料重比差异不显著(P>0.05);添加柠檬酸对试验兔平均日采食量、腹泻率和死亡率均影响不显著(P>0.05),腹泻率以Ⅱ组、Ⅲ组最低;死亡率以对照2组和Ⅲ组最低。2)添加柠檬酸后,各试验组粗蛋白质、粗灰分表观消化率极显著高于对照1组(P<0.01);各试验组能量、干物质、中性洗涤纤维、酸性洗涤纤维表观消化率均与对照1组差异不显著(P>0.05)。3)添加柠檬酸对试验兔屠宰性能及肉品质指标没有显著影响(P>0.05)。4)各组间血清总抗氧化能力差异不显著(P>0.05);Ⅲ组血清超氧化物歧化酶活性显著高于对照1组、对照2组(P<0.05),与Ⅰ组、Ⅱ组差异不显著(P>0.05)。综合考虑本试验所测指标,生长肉兔饲粮中适宜的柠檬酸添加水平为1.5%。

This experiment was conducted to study the effects of citric acid on growth performance,nutrient apparent digestibilities,serum antioxidant indexes and meat quality of growth meat rabbits.Three hundred healthy weanling Hyla rabbits at age of 35 days were randomly divided into 5 groups with 60 replicates in each group and 1 rabbit in each replicate.Rabbits in the control group 1 were fed a basal diet,rabbits in the control group 2 were fed the basal diet supplemented with antibiotics(enramycin 20 g/t+chlorotetracycline 300 g/t),rabbits in experimental groups were fed the basal diet supplemented with 0.5%(groupⅠ),1.0%(groupⅡ)and 1.5%(groupⅢ)citric acid,respectively.There was a pretrial period of 5 days followed by an experi mental period of 22 days.The experiment results showed as follows:1)the average daily weight gain in groupⅠand control group 2 was significantly higher than that in the control group 1(P<0.05),and there were no significant difference between the two groups(P>0.05);there was no significant difference in average daily weight gain between groupsⅡ,Ⅲand two control groups(P>0.05);the feed/gain in groupⅠand control group 2 was significantly lower than that in control group 1(P<0.05),but there were no significant difference between groupⅠand control group 2(P>0.05),there were no significant difference in feed/gain among all experimental groups(P>0.05);dietary citric acid had no significant effect on average daily feed intake,diar rhea rate and mortality rate(P>0.05);the diarrhea rate in groupsⅡandⅢwere the lowest,the mortality rate in groupⅢand control group 2 were the lowest.2)Compared with the control group 1,dietary citric acid significantly increased the apparent digestibilities of crude protein and ash(P<0.01),and had no significant difference in the apparent digestibilities of energy,dry matter,neutral detergent fiber and acid detergent fiber(P>0.05).3)Dietary citric acid had no significant difference in slaughter performance and meat quality inde xes(P>0.05).4)The serum total antioxidant capacity had no significant difference among groups(P>0.05),the serum superoxide dismutase activity in groupⅢwas significantly higher than that in control groups 1 and 2(P<0.05),but had no significant difference with groupsⅠandⅡ(P>0.05).Considering all indices of this experiment,the appropriate citric acid supplemental level in the diet of growth meat rabbits is 1.5%.[Chinese Journal of Animal Nutrition,2020,32(5):2282 2289]