饲粮中添加甜菜碱和表没食子儿茶素没食子酸酯对育肥猪生长性能、肉品质、血清生化和抗氧化指标的影响

Effects of Dietary Betaine and Epigallocatechin Gallate on Growth Performance,Meat Quality,Serum Biochemical and Antioxidant Indices of Finishing Pigs

本试验旨在研究饲粮中添加甜菜碱和表没食子儿茶素没食子酸酯(EGCG)对育肥猪生长性能、肉品质、血清生化和抗氧化指标的影响。选取81头平均体重为90.03 kg的育肥期“杜×长×大”三元杂交猪,随机分为3组,每组3个重复,每个重复9头猪。对照组饲喂基础饲粮,试验Ⅰ组在基础饲粮中添加2500 mg/kg的甜菜碱,试验Ⅱ组在基础饲粮中添加2500 mg/kg的甜菜碱和1000 mg/kg的EGCG。预试期5 d,正试期40 d。结果表明:1)与对照组相比,试验Ⅰ、Ⅱ组的平均日采食量均显著降低(P<0.05)。2)与对照组相比,试验Ⅰ、Ⅱ组的背膘厚和背最长肌24 h滴水损失均显著降低(P<0.05),试验Ⅰ组的背最长肌肌内脂肪含量显著升高(P<0.05)。3)各组之间背最长肌氨基酸含量均无显著差异(P>0.05)。与对照组相比,试验Ⅰ、Ⅱ组的背最长肌二十二碳酸含量均显著降低(P<0.05);各组之间背最长肌其他脂肪酸含量均无显著差异(P>0.05)。4)与对照组相比,试验Ⅰ组的背最长肌肌球蛋白重链Ⅱb(MyHCⅡb)的mRNA相对表达水平显著降低(P<0.05),背最长肌肌球蛋白重链Ⅱx(MyHCⅡx)和固醇调控元件结合蛋白1(SERBP1)的mRNA相对表达水平显著升高(P<0.05);试验Ⅱ组的背最长肌肌球蛋白重链Ⅱa(MyHCⅡa)、MyHCⅡx和过氧化物酶体增殖物激活受体α(PPARα)的mRNA相对表达水平显著升高(P<0.05)。5)与对照组相比,试验Ⅰ组的血清总胆固醇和甘油三酯含量显著降低(P<0.05),血清谷胱甘肽过氧化物酶活性显著升高(P<0.05);试验Ⅱ组的血清总胆固醇和丙二醛含量显著降低(P<0.05),血清谷胱甘肽过氧化物酶活性和总抗氧化能力显著升高(P<0.05)。由此可见,饲粮中添加甜菜碱或甜菜碱和EGCG能提高育肥期“杜×长×大”三元杂交猪的饲料利用率,通过降低背膘厚和滴水损失改善猪肉品质,并提升血清脂质代谢和抗氧化能力;此外,饲粮中添加甜菜碱还能提高肌内脂肪含量。

This experiment was conducted to investigate the effects of dietary betaine and epigallocatechin gallate(EGCG)on growth performance,meat quality,serum biochemical and antioxidant indices of finishing pigs.Eightyone“Duroc×Landrace×Yorkshine”crossed finishing pigs with an average body weight of 90.03 kg were randomly divided into 3 groups with 3 replicates per group and 9 pigs per replicate.Pigs in the control group were fed a basal diet,pigs in experimental groupⅠwere fed the basal diet supplemented with 2500 mg/kg betaine,and others in experimental groupⅡwere fed the basal diet supplemented with 2500 mg/kg betaine and 1000 mg/kg EGCG.The preexperimental period lasted for 5 days,and the experimental period lasted for 40 days.The results showed as follows:1)compared with the control group,the average daily feed intake of experimental groupsⅠandⅡwas significantly decreased(P<0.05).2)Compared with the control group,the backfat thickness and longissimus dorsi 24 h drip loss of experimental groupsⅠandⅡwere significantly decreased(P<0.05),and the longissimus dorsi intramuscular fat content of experimental groupⅠwas significantly increased(P<0.05).3)There were no significant differences in longissimus dorsi amino acid contents among all groups(P>0.05).Compared with the control group,the longissimus dorsi docosanoic acid content of experimental groupsⅠandⅡwas significantly decreased(P<0.05);there were no significant differences in longissimus dorsi other fatty acid contents among all groups(P>0.05).4)Compared with the control group,the mRNA relative expression level of myosin heavy chainⅡb(MyHCⅡb)in longissimus dorsi of experimental groupⅠwas significantly decreased(P<0.05),and the mRNA relative expression levels of myosin heavy chainⅡx(MyHCⅡx)and sterol regulatory element binding protein 1(SERBP1)in longissimus dorsi of experimental groupⅠwere significantly increased(P<0.05);the mRNA relative expression levels of myosin heavy chainⅡa(MyHCⅡa),MyHCⅡx and peroxisome proliferatoractivated receptorα(PPARα)in longissimus dorsi of experimental groupⅡwere significantly increased(P<0.05).5)Compared with the control group,the contents of total cholesterol and triglycerides in serum of experimental groupⅠwere significantly decreased(P<0.05),and the serum glutathione peroxidase activity was significantly increased(P<0.05);the contents of total cholesterol and malondialdehyde in serum of experimental groupⅡwere significantly decreased(P<0.05),and the serum glutathione peroxidase activity and total antioxidant capacity were significantly increased(P<0.05).In conclusion,the addition of betaine or betaine and EGCG in diet can improve the feed utilization rate,improve the meat quality by decreasing backfat thickness and drop loss,and enhance serum lipid metabolism and antioxidant capacity of“Duroc×Landrace×Yorkshine”crossed finishing pigs;moreover,the addition of betaine in diet can increase the intramuscular fat content.