日粮蛋白质、赖氨酸、蛋氨酸及苏氯酸水平对早期断奶仔猪免疫机能的影响

本研究分两次试验进行 ,试验 1研究两个蛋白质水平 ( 1 8% ,2 0 % )及三个赖氨酸水平 ( 1 .0 % ,1 .3%和 1 .6 % )对机体免疫机能的影响 ;试验 2研究两个蛋氨酸水平 ( 0 .2 9% ,0 .39% )和三个苏氨酸水平( 0 .6 0 % ,0 .6 8%和 0 .76 % )对机体免疫机能的影响。试验日粮均为简单型日粮 ,试验动物为早期断奶仔猪 ,其日龄体重分别为 2 5± 3日、6 .78± 0 .0 8kg与 2 6± 1日龄、6 .6 8± 0 .0 4kg。测定不同蛋白质和氨基酸水平下 ,免疫器官重量、淋巴细胞数量及组成、血液IgG效价、注射PHA皮褶厚度变化及SRBC(绵羊红细胞 )免疫后抗体效价。结果表明 ,日粮不同蛋白质和赖氨酸水平对血清IgG效价无影响 ,在皮褶厚度的变化的影响上 ,两者交互作用极显著 (P <0 .0 1 )。苏氨酸及蛋氨酸的不同水平显著影响血液中IgG效价及抗SRBC抗体效价 (P <0 .0 5) ,机体免疫机能最佳时适宜的蛋白质、赖氨酸、蛋氨酸及苏氨酸水平分别为 1 8% ,1 .3% ,0 .39%及 0 .6 8%。

Effects of Different Dietary Levels of Protein, Lysine, Methionine and Threonine on Immune Function in Early-weaned Piglets

This study was conducted in two experiments. Exp.1 studied the effects of two levels of protein and three levels of lysine on immune function of piglets. Exp.2 studied the effects of two levels of methionine and three levels of threonine on immune function of piglets. Animals were early weaned piglets, 25±3d,6.78±0.08kg and 26±1d, 6.68±0.04kg respectively in two experiments, fed with simple type diet. Under different dietary levels of protein and amino acids, the weight of immune organ, blood lymph ocyte quantity and component, serum IgG titer, skin fold thicknes response to PHA skin test, antibody effectiveness by SRBC immunization were measured. Results showed that different dietary levels of protein and lysine had no influence on serum IgG titer, there was an interaction in skin fold thickness response to PHA skin test between protein levels and lysine levels(p<0.01). Different levels of methionine and threonine had significant influence on serum IgG titer and SRBC antibody effectiveness(p<0.05), the dietary levels of protein, lysine, methionine and threonine for maximal immunity were 18%,1.3%, 0.39% and 0.68% respectively.