饲养密度对新西兰白兔生长性能、行为、免疫器官指数和血清抗氧化指标的影响

Effects of stocking density on the growth performance,behavior,immune organ index and antioxidant index of New Zealand white rabbits

试验旨在探讨饲养密度对家兔生长性能、行为方式、免疫器官指数和血清抗氧化指标的影响。试验选取35日龄体重相近(943.86±51.13)g,健康的雄性新西兰白兔120只,随机分为4组,每组6个重复(笼),即Ⅰ组每个重复(笼)2只(5只/m^(2))、Ⅱ组每个重复(笼)4只(10只/m^(2))、Ⅲ组每个重复(笼)6只(15只/m^(2))、Ⅳ组每个重复(笼)8只(20只/m^(2))。预饲期5 d,试验期35 d。结果显示:在生长性能方面,Ⅰ组和Ⅱ组家兔的末重和平均日增重显著高于Ⅲ组(P<0.05),且极显著高于Ⅳ组(P<0.01),Ⅲ组的末重和平均日增重显著高于Ⅳ组(P<0.05);平均日采食量Ⅰ组和Ⅱ组极显著高于Ⅲ组(P<0.01),Ⅲ组高于Ⅳ组(P<0.01)。在趴卧行为发生率方面,家兔的趴卧行为Ⅰ组和Ⅱ组极显著低于Ⅲ组(P<0.01),Ⅲ组极显著低于Ⅳ组(P<0.01);Ⅰ组和Ⅱ组的运动和站立行为发生率差异均不显著(P>0.05),其余各组之间差异均极显著(P<0.01);Ⅰ组和Ⅱ组的采食行为发生率均极显著高于Ⅲ组和Ⅳ组(P<0.01);Ⅰ组和Ⅱ组的修饰行为发生率极显著高于Ⅲ组和Ⅳ组(P<0.01),而啃咬行为发生率则显著低于Ⅲ组和Ⅳ组(P<0.05)。在免疫器官指数方面,Ⅰ组和Ⅱ组家兔的脾脏指数显著高于Ⅳ组(P<0.05),胸腺指数均显著高于Ⅲ组和Ⅳ组(P<0.05)。在血清抗氧化能力方面,Ⅱ组和Ⅲ组家兔的血清T-AOC浓度和SOD活性均显著高于Ⅳ组(P<0.05);Ⅰ组、Ⅱ组和Ⅲ组血清中MDA含量均显著低于Ⅳ组(P<0.05)。以上结果表明,适当降低饲养密度能够改善家兔的生长性能和行为状态,提高其免疫和抗氧化能力,在考虑饲养笼具利用率的基础上,以Ⅱ组4只/笼(10只/m^(2))的饲养密度效果最佳。

This study was to investigate the effects of stocking density on the growth performance,behavior index,immune organ index and serum antioxidant index of rabbits.A total of 12035-day-old healthy male New Zealand white rabbits of similar body weight(943.86±51.13)g were selected and randomly divided into 4 groups with 6 replicates per group.That is,there were 2 cages per replicate(5/m^(2))in Group Ⅰ,4 cages per replicate(10/m^(2))in Group Ⅱ,6 cages per replicate(15/m^(2))in Group Ⅲ and 8 cages per replicate(20/m^(2))in Group Ⅳ.The pre-feeding period lasted for 5 days and the experimental stage for 35 days.The results showed that,in terms of growth performance,the final weight and average daily gain in Groups Ⅰ and Ⅱ were significantly higher than that in Group Ⅲ(P<0.05),and extremely significantly higher than that in Group Ⅳ(P<0.01).The final weight and average daily gain in Group Ⅲ was significantly higher than that in Group Ⅳ(P<0.05).The average daily feed intake in Groups Ⅰ and Ⅱ was extremely significantly higher than that in Group Ⅲ(P<0.01),and that in Group Ⅲ was extremely significantly higher than that in Group Ⅳ(P<0.01).In terms of the incidence of recumbent behavior indexes,those of the rabbits in Groups Ⅰ and Ⅱ were significantly lower than those in Group Ⅲ(P<0.01),and those in Group Ⅲ were significantly lower than those in Group Ⅳ(P<0.01).There were no significant difference in the incidence of movement and standing behavior between Group Ⅰ and Group Ⅱ(P>0.05),while there were extremely significant differences among the other groups(P<0.01).The incidence of feeding behavior of Groups Ⅰ and Ⅱ was significantly higher than that of Groups Ⅲ and Ⅳ(P<0.01).The incidence of modification behavior of Groups Ⅰ and Ⅱ was significantly higher than that of Groups Ⅲ and Ⅳ(P<0.01),but the incidence of bite behavior was significantly lower(P<0.05).In terms of immune organ indexes,the spleen index of the rabbits in Groups Ⅰ and Ⅱ was significantly higher than that in Group Ⅳ(P<0.05),and the thymus index of the rabbits in Groups Ⅲ and Ⅳ was significantly higher than that in Groups Ⅲ and Ⅳ(P<0.05).In terms of serum antioxidant capacity,the serum T-AOC concentration and SOD activity of the rabbits in Groups Ⅱ and Ⅲ were significantly higher than those in Group Ⅳ(P<0.05);the MDA content in the serum in GroupsⅠ,Ⅱ and Ⅲ was significantly lower than that in Group Ⅳ(P<0.05).The above results indicated that proper reduction of feeding density could improve the growth performance and behavior state of rabbits,and increase their immune and antioxidant capacity.In this experiment,based on the consideration of the utilization rate of feeding cages,the optimal stocking density of Group Ⅱ with 4 rabbits/cage(10/m^(2))was the best.