不同水平乳铁蛋白对滇撒配套系仔猪生产性能、小肠形态学和机体抗病能力的影响

The Effect of Different Levels of Lactoferrin on the Growth Performance,Small Intestinal Morphology and Body Resistance to Disease of Diansa Weaning Piglets

本试验旨在研究不同水平乳铁蛋白(LF)对滇撒配套系断奶仔猪生产性能、肠道保护和机体抗病能力的影响。选用日龄为(28±2)d,平均体重为(6.56±0.75)kg的健康滇撒配套系断奶仔猪240头,随机分为5个处理,每个处理48头,6个重复,每个重复8头猪,分别饲喂基础饲粮(对照组),基础饲粮+125mg·kg^(-1)乳铁蛋白,基础饲粮+250mg·kg^(-1)乳铁蛋白,基础饲粮+500mg·kg^(-1)乳铁蛋白和抗生素组(50mg·kg^(-1)土霉素),试验期42d。试验结束时,每个处理中每个重复随机选4头,每个处理共24头仔猪,经前腔静脉采血,分离血清,检测血清免疫球蛋白G(IgG)、一氧化氮(NO)含量,乳酸脱氢酶(LDH)、一氧化氮合酶(NOS)和溶菌酶(LSZ)活性及总铁结合力(TIBC)。每个处理中每个重复屠宰1头仔猪,共6头,收集心、肝、脾以检测铁调素(Hepcidin)、β防御素1(pBD-1)、β防御素2(pBD-2)和β防御素3(pBD-3)基因mRNA相对表达量。结果表明:1)250mg·kg^(-1)乳铁蛋白组断奶仔猪的末重、日增重、日采食量显著高于对照组和抗生素组(P<0.05),料重比和腹泻率则显著低于对照组和抗生素组(P<0.05);2)250mg·kg^(-1)组的IgG和NO显著高于对照组(P<0.05),TIBC极显著高于抗生素组和对照组(P<0.01);250mg·kg^(-1)乳铁蛋白组十二指肠V/C,空肠绒毛长度、V/C,回肠绒毛长度、V/C极显著高于抗生素组和对照组(P<0.01),250mg·kg^(-1)乳铁蛋白组回肠隐窝深度极显著低于对照组(P<0.01);腹泻率、IgG、NO、LSZ、十二指肠隐窝深度、十二指肠绒毛长度/隐窝深度、空肠绒毛长度、空肠隐窝深度和空肠绒毛长度/隐窝深度随乳铁蛋白添加水平呈二次曲线变化(P<0.05);3)250mg·kg^(-1)乳铁蛋白组极显著高于对照组和抗生素组断奶仔猪心、肝中的Hepcidin mRNA的表达量(P<0.01),125mg·kg^(-1)乳铁蛋白组显著高于对照组和抗生素组断奶仔猪肝中Hepcidin mRNA的表达量(P<0.05),肝Hepcidin mRNA表达量极显著的高于心和脾(P<0.01);250mg·kg^(-1)乳铁蛋白组心、脾的pBD-1mRNA的表达量极显著高于其他组(P<0.01);肝的pBD-2mRNA表达量显著或极显著的高于心或脾(P<0.05,P<0.01);添加量为250mg·kg^(-1)时,心和脾的pBD-3mRNA的表达量极显著高于其他组(P<0.01)。结果提示,饲粮中添加乳铁蛋白可明显改善滇撒配套系仔猪的生产性能;改善血清免疫学参数和小肠形态学;能够通过诱导滇撒配套系仔猪的心、肝和脾Hepcidin和pBD-1,pBD-2,pBD-3基因表达上调方式增强仔猪抗病能力;在本试验条件下,综合生产性能、血清免疫学和小肠形态学参数二次曲线结果,滇撒配套系仔猪日粮中乳铁蛋白的适宜添加量为250~300mg·kg^(-1)。

This experiment was conducted to investigate the effects of different levels of lactoferrin(LF)on growth performance,intestinal protection and the body resistance to disease of Diansa weaning piglets.Two hundred and forty healthy Diansa weaning piglets,(28±2)days of age with(6.56±0.75)kg of average body weight,were allocated randomly to 5groups,48 for each group,and each had 6replicates with 8piglets per replicate.They were fed with basal diet(control group),basal diet + 125 mg·kg^(-1) LF,basal diet + 250 mg·kg^(-1) LF,basal diet + 500mg·kg^(-1) LF and antibiotics positive group(50mg·kg^(-1) terramycin),respectively.The trial period lasted 42 d.At the end,24 piglets,with 4piglets in each replicate per each group,were selected,and the test piglets were collected blood from precava,then serum were separated.The IgG and NO content,LDH,NOS and LSZ activity and TIBC of serum were detected.Six piglets,1piglet in each replicate per each group,were slaughtered.The heart,liver and spleen were collected to detect Hepcidin andβdefense 1(pBD-1),βdefense 2(pBD-2)andβdefense 3(pBD-3)genes mRNA expression.The results showed that:1)The final weight,ADG and ADFI of 250mg·kg^(-1) LF group were significantly higher than those of control group and terramycin group(P<0.05),feed conversion and diarrhea rate were significantly lower than those of control group and terramycin group(P<0.05).2)IgG levels,NO content of 250mg·kg^(-1) LF group were significantly higher than those of control group(P<0.05),TIBC of 250mg·kg^(-1) LF group were extremely significantly higher than those of control group and terramycin group(P<0.01).V/C of duodenum,villus height and V/C of jejunum,villus height and V/C of ileum in 250mg·kg^(-1)LF group were extremely significantly higher than those in control group and terramycin group(P<0.01),crypt depth of ileum in 250 mg·kg^(-1) LF group were extremely significantly lower than those in control group(P<0.01).Results showed that diarrhea rate,IgG,NO,LSZ,crypt depth of duodenum,V/C of duodenum,villus height of jejunum,crypt depth of jejunum,V/C of jejunum increased with a quadratic curve by the LF adding levels(P<0.05);3)Hepcidin mRNA expression in heart and liver of piglets in 250 mg·kg^(-1) LF group were extremely significantly higher than those of control group and terramycin group(P<0.01).Hepcidin mRNA expression in liver in 125mg·kg^(-1) LF group were significantly higher than those of control group and terramycin group(P<0.05).The Hepcidin mRNA expression in liver was extremely significantly higher than that in the heart and spleen(P<0.01).The pBD-1 mRNA expression in the heart and spleen in 250mg·kg^(-1)LF group were extremely significantly higher than those of the other groups(P<0.01).The pBD-2mRNA expression in liver was significantly or extremely significant higher than those in heart and the spleen(P<0.05,P<0.01).When the adding level was250mg·kg^(-1),the pBD-3 mRNA expression in heart and spleen were extremely significantly higher than the other groups(P<0.01).Results suggest that adding LF in the diet can obviously improve the growth performance,serum immunological parameters and small intestinal morphology of Diansa weaning piglets,and enhance piglets disease resistance through inducing genes expression of Hepcidin,pBD-1,pBD-2,pBD-3in heart,liver and spleen of Diansa weaning piglets.In this experimental conditions,based on quadratic curve results of growth performance,serum immunological and small intestinal morphology parameters,the adequate amount of LF in Diansa weaning piglets diet was 250-300mg·kg^(-1).