南瓜籽壳对不同生长阶段西杂肉牛生长性能、血清生化和免疫指标及激素水平的影响

Effects of Pumpkin Seed Shells on Growth Performance,Serum Biochemical Parameters,Immune Indexes,and Hormone Levels of Simmental Crossbred Cattle at Different Growth Stages

[目的]研究日粮中添加南瓜籽壳对不同生长阶段西杂肉牛生长性能、血清生化和免疫指标及激素水平的影响。[方法]选取体况良好的西门塔尔杂交公牛共40头,按照体重分为5组,分别为试验1组(300 kg左右)、试验2组(400 kg左右)、试验3组(500 kg左右)、试验4组(600 kg左右)和试验5组(700 kg左右),每组8头,分栏饲养,基础日粮中均添加10%的南瓜籽壳。试验期为90 d,预试期20 d,正试期70 d。记录各组肉牛试验期间体重及采食情况,计算平均日增重、平均日采食量和平均料重比;试验结束时采集血液样本制备血清,测定血清生化指标、免疫指标及激素水平。[结果]随着肉牛体重的增加,日采食量逐渐增加,试验4组和5组平均日采食量显著(P<0.05)高于其他组;试验1组平均料重比最低,显著(P<0.05)低于其他组。试验4组血清总蛋白(TP)、尿素氮(BUN)含量显著(P<0.05)高于试验1组、3组。试验2组血清免疫球蛋白M(IgM)含量显著(P<0.05)高于其他组。试验1组血清皮质醇(COR)水平显著(P<0.05)高于试验3组、4组、5组,试验5组血清降钙素(CT)水平显著(P<0.05)高于其他各组,试验4组、5组C反应蛋白水平显著(P<0.05)高于试验1组。[结论]西杂肉牛日粮中添加南瓜籽壳,可增加采食量,提高机体蛋白质利用率,对增强动物免疫力具有一定作用,可作为一种粗饲料资源进行开发利用。

[Objective]The aim of the present study was to assess the effects of dietary supplementation of pumpkin seed shells on growth performance,serum biochemical parameters,immune indexes,and hormone levels of Simmental crossbred cattle at different growth stages.[Method]A total of 40 male Simmental crossbred cattle in good body condition were selected and divided into the following 5 groups based on body weights:experimental group 1(n=8,around 300 kg),experimental group 2(n=8,around 400 kg),experimental group 3(n=8,around 500 kg),experimental group 4(n=8,around 600 kg)and experimental group 5(n=8,around 700 kg).All of the experimental cattle were raised in separate pens.For each group,pumpkin seed shells were supplemented to the basal diet at a ratio of 10%.The experimental period was 90 days comprising a 20-day pre-trial and a 70-day formal trial.The body weight and feed intake of the experimental cattle in each group during the experiment were recorded,and the average daily weight gain,average daily feed intake and average feed to weight gain ratio were calculated.At the end of the experiment,blood samples were collected to prepare serum.Serum biochemical parameters,immune indexes and hormone levels were measured.[Result]As the body weights elevated,the daily feed intake of the experimental cattle gradually increased.The average daily feed intake of experimental groups 4 and 5 was significantly(P<0.05)higher than the other groups.The average feed to weight gain ratio in experimental group 1 was the lowest and significantly(P<0.05)lower than the other groups.Compared to experimental groups 1 and 3,the serum contents of total protein(TP)and blood urea nitrogen(BUN)in experimental group 4 were significantly(P<0.05)higher.Experimental group 2 had significantly(P<0.05)higher serum immunoglobulin M(IgM)content than the other groups.In comparison to experimental groups 3,4 and 5,experimental group 1 had significantly(P<0.05)higher serum cortisol(COR)level.Experimental group 5 had significantly(P<0.05)higher serum calcitonin(CT)level than the other groups.The C-reactive protein level in experimental groups 4 and 5 was significantly(P<0.05)higher than experimental group 1.[Conclusion]Supplementation of pumpkin seed shells in the basal diet of Simmental crossbred cattle could increase the feed intake and improve protein utilization efficiency,and also had certain effects on enhancing immunity.It can be developed and utilized as a roughage resource.