复合特异性卵黄抗体对18～28日龄犊牛生长、腹泻和免疫力的影响

Effects of Composite Specific Immunoglobulin of Yolk on Growth,Diarrhea and Immunity of Calves Aged from 18 to 28 Days

本文旨在饲粮中添加复合特异性卵黄抗体（IgY）探究其对18～28日龄犊牛生长、腹泻和免疫力的影响。选取初生中国荷斯坦公犊牛20头,10日龄之前饲喂鲜奶,之后随机分为2组,对照（CON）组饲喂基础饲粮;试验（IGY）组在基础饲粮中日添加45 mg/kgBW的复合特异性IgY。预试期为犊牛11～17日龄,期间进行代乳品过渡,正试期为18～28日龄。分别于犊牛18和28日龄晨饲前称重,每天记录犊牛采食量并进行粪便评分。试验结束当天（28日龄）晨饲前颈静脉采血,测定血清中总抗氧化能力（T-AOC）和碱性磷酸酶（AKP）活性以及免疫球蛋白、一氧化氮（NO）、溶菌酶（LZM）浓度。结果表明：饲粮添加复合特异性Ig Y虽然对犊牛平均日增重和料重比无显著影响（P〉0.05）,却有助于降低犊牛的粪便评分和腹泻率,作用显著（P〈0.05）;IGY组较CON组极显著提高了犊牛血清中免疫球蛋白G（Ig G）、免疫球蛋白M（IgM）和免疫球蛋白A（IgA）的浓度（P〈0.01）,分别提高7.19%、5.71%和8.50%;IGY组T-AOC极显著高于CON组（P〈0.01）,而NO浓度却显著低于CON组（P〈0.05）;IGY组血清LZM浓度极显著低于CON组（P〈0.01）,复合特异性Ig Y对血清AKP活性却无显著影响（P〉0.05）。结果提示,饲粮中添加复合特异性Ig Y通过提高犊牛免疫球蛋白浓度和抗氧化能力以及发挥Ig Y本身抗原抗体反应,增强犊牛免疫能力和抵抗外界应激能力,降低了腹泻率,促进了犊牛健康。

This study aimed to investigate the effects of dietary supplementation of composite specific immunoglobulin（ Ig） of yolk（ Ig Y） on growth,diarrhea and immunity of calves aged from 18 to 28 days. Tw enty new born Chinese Holstein bull calves were selected and fed fresh milk until 10 days of age,then were randomly assigned to one of tw o groups. Calves were fed a basal diet（ CON group） or the basal diet daily supplemented with 45 mg/kg BW composite specific（ IGY group）. The pre-experiment was from 11 to 17 days of age when a milk replacer was gradually used,after that the formal experiment was carried out from 18 to 28 days of age. W eight of calves was recorded at 18 and 28 days of age,respectively. Feed intake and fecal score were recorded daily. Blood samples were obtained by jugular venipuncture from calves at 28 days of age. Serum total antioxidant capacity（ T-AOC）,the activity alkaline phosphatase（ AKP） and concentrations of serum Ig,nitric oxide（ NO） and lysozyme（ LZM） were determined. The results show ed as follow s： dietary supplementation of Ig Y had no significant effects on average daily gain and feed to gain ratio（ P〉0.05）. Compared with CON group,IGY group significantly decreased fecal score and diarrhea incidence（ P〈0.05）. Serum concentrations of Ig G,Ig Mand Ig A in IGY group were significantly higher than those in CON group（ P〈0.01）,and were increased by 7.19%,5.71% and 8.50%,respectively. Serum T-AOC in IGY group was significantly higher compared to that in CON group（ P〈0. 01）,how ever,serum NO concentration was significantly decreased in CON group（ P〈0. 05）. Serum concentration of LZMin IGY group was significantly low er compared to that in CON group（ P〈0.01）,but serum activity of AKP was not influenced（ P〈0.05）. In summary,diets supplemented with composite specific Ig Y improve immunity and the capacity of resist to external stress by increasing serum Ig concentrations and antioxidant capacity,and developing antigen-antibody reaction of Ig Y to decrease diarrhea incidence and promote health of calves.