新型耐热植酸酶对断奶仔猪免疫功能及抗氧化功能的影响

Effect of new heat-resistant phytase on immune function and antioxidant capacity of weaned piglets

研究旨在探讨低磷日粮中添加新型耐热植酸酶替代一部分磷酸氢钙对断奶仔猪免疫功能和抗氧化功能的影响。试验选用256头遗传背景相同、初始体重为(8.37±0.97)kg的30日龄断奶仔猪,按完全随机区组设计分为4个处理,每个处理设4个重复,每个重复16头仔猪。4个处理分别饲喂基础日粮、低磷日粮、低磷日粮基础上添加500 U/kg新型耐热植酸酶和低磷日粮基础上添加1 000 U/kg新型耐热植酸酶的试验日粮。结果表明:①基础日粮组及新型耐热植酸酶添加组相比低磷日粮组显著降低了断奶仔猪的死亡率(P<0.05)。②各处理之间血液生化指标谷丙转氨酶(ALT)、谷草转氨酶(AST)酶活和三种免疫球蛋白IgG、IgA、IgM差异均不显著(P>0.05),但新型耐热植酸酶添加组的IgG、IgA、IgM有升高的趋势。③各处理间抗氧化指标超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、谷胱甘肽过氧化物酶(GSH-Px)、谷胱甘肽还原酶(GR)等抗氧化酶酶活及丙二醛(MDA)含量差异均不显著(P>0.05),但新型耐热植酸酶添加组和基础日粮组抗氧化能力有上升趋势。由此可知,断奶仔猪日粮中添加新型耐热植酸酶替代部分无机磷,能一定程度上提高断奶仔猪免疫力及抗氧化能力。综合各项指标,1 000 U/kg的新型耐热植酸酶能起到更好的替代无机磷的作用。

This experiment was conducted lo study the effects of new heat-resistant phytase（NHP）on immune function and antioxidant capacity in weaned piglets by replacing part of calcium hydro phosphate by NHP in low phosphors diet. A total of 256 piglets weaned at 30 d of age [（8.37 ± 0.97） kg of BW] were randomly allotted to 4 treatments with 4 replicates of 16 piglets using a randomized complete-block design, based on initial BW and sex. They were fed basal diet, low-phosphorus dicl, lowphosphorus diet ＋ 500 U/kg NHP, low-phosphorus diet ＋ 1000 U/kg NHP, respectively. The resuhs showed as follows： （1）Compared with lhe other groups, mortality in low-phosphorus diet group is higher （P〈0.05）. （2）The concentration of serum ALT, AST, IgG, IgA and IgM of trealmenl group did not differ significantly （P〉0.05）. But serum IgG, IgA and IgM in 500, 1 000 U/kg NHP groups had the tendency to be increased. （3）Antioxidant superoxide dismutase indicators（SOD）, catalase（CAT）, glutathione peroxidase （GSH-Px）, glutathione reductase （GR） and malondialdehyde （MDA） had no significant differences in each treatment （P〉0.05） . But the antioxidant capacity tended to be increased in basal diet group and 500, 1 000 U/kg NHP groups. In conclusion, supplementation of NHP in substition of part of inorganic phosphorus could improve weaned piglets immunity and antioxidanl capacity. So taking immunity and antioxidanl capacilyinto consideration, the best dosage for PHY is 1 000 U/kg.