日粮中不同锌及维生素A水平对肉仔鸡生产性能、免疫性能和有关酶及激素的影响

THE INFLUENCE OF VARIOUS DIETARY Zn AND VA LEVELS ON PRODUCTION PERFORMANCE,IMMUNOLOGY COMPETENCE,ACTIVITY OF CuZn-SOD,ALK AND INSULIN CONCENTRATION OF SERUM IN BROILERS

以AA肉仔鸡为试验动物 ,采用6×2(Zn×VA)重复实验设计 ,研究了日粮添加不同水平的锌(Zn)(40 ,80 ,120 ,160 ,200和320mg/kg)和维生素A(VA)(2700和8800IU/kg)对生产性能、免疫性能、7周龄血清和肝脏CuZn -SOD活性、血清碱性磷酸酶活性及血清胰岛素浓度的影响。结果表明 ,肉仔鸡对Zn的需要量有阶段性区别 ,前期添加320mg/kg,后期添加80～120mg/kg能获得较好的生产性能和免疫性能。VA的添加量为2700IU/kg 时前后期的生产性能均较佳。日粮Zn水平对血清CuZn -SOD的影响极显著(P<0.01) ,Zn水平为80～160mg/kg 时活性最大 ;日粮Zn水平对肝脏CuZn -SOD的影响接近显著水平 ,Zn水平为160～200mg/kg 时活性最大 ;日粮Zn水平、VA水平及二者的交互作用对血清碱性磷酸酶活性的影响均极显著(P<0.01) ,Zn的添加水平为80mg/kg时 ,酶活性最大 ,日粮高水平VA(8800IU/kg)使酶活性显著增加(P<0.01)。日粮Zn及VA水平对血清胰岛素浓度均有极显著影响(P<0.01)。高Zn(320mg/kg)使胰岛素浓度明显升高 。

A 6×2(Zn×VA)experiment with repeats was designed to investigate the influence of various dietary Zn and VA levels on production performance,immunology competence,the activity of CuZn-SOD,and ALK and insulin concentration of serum in broilers.Results showed that the Zn requirement was different in different stages,in early stage was 320mg/kg,in later stage was 80～120mg/kg.VA requirement was 2700IU/kg through the whole period.Dietary Zn level influenced the activity of serum CuZn-SOD significantly(P<0.01),serum CuZn-SOD activity reached its peak when dietary Zn level was 80～120mg/kg;dietary Zn,VA and their interaction influenced the activity of serum Alk significantly(P<0.01),when the supplemental level of Zn was 80mg/kg,VA was 8800IU/kg,serum Alk activity reached its peak.Dietary Zn and VA level influenced serum insulin concentration significantly (P<0.01),when zinc level was 320mg/kg,insulin concentration reached its peak,high dietary VA level(8800IU/kg)depressed the insulin concentration.