摘要
本试验旨在研究叶酸(FA)和包被叶酸(CFA)对围产期奶牛泌乳性能、瘤胃发酵和肝脏FA代谢的影响。选取胎次[(2.03±0.18)胎]、体重[(676.0±33.6)kg]、上一泌乳期产奶量[(10155.0±256.2)kg]和预产期相近的围产期奶牛80头,依据随机区组设计随机分为4组,每组20头牛。对照组(CON组)饲喂基础饲粮,试验组分别在基础饲粮的基础上添加6.75 g/d CFA(含有2%FA,CFA组)、135 mg/d FA(LFA组)和270 mg/d FA(HFA组)。奶牛产前35 d进入试验,产后0~21 d为样品采集期。结果表明:1)CFA组产奶量、4%乳脂校正乳产量、乳蛋白产量以及饲料效率显著高于CON组、LFA组和HFA组(P<0.05),乳脂产量显著高于CON组和LFA组(P<0.05)。2)与CON组相比,CFA组、LFA组和HFA组瘤胃FA含量、超氧化物歧化酶(SOD)和谷胱甘肽过氧化物酶(GSH-Px)活性以及总挥发性脂肪酸(TVFA)含量显著提高(P<0.05),瘤胃丙二醛(MDA)含量显著降低(P<0.05)。同时,与CFA组相比,LFA组和HFA组瘤胃SOD和GSH-Px活性以及TVFA含量显著提高(P<0.05),瘤胃MDA含量和乙酸/丙酸值显著降低(P<0.05)。3)各组间瘤胃菌群α多样性指数无显著差异(P>0.05)。在门水平上,LFA组瘤胃拟杆菌门相对丰度显著高于其他组(P<0.05),瘤胃厚壁菌门相对丰度显著低于其他组(P<0.05)。在属水平上,LFA组瘤胃未培养瘤胃细菌属和普雷沃氏菌科UCG-001相对丰度显著高于其他组(P<0.05),CFA组、LFA组和HFA组瘤胃理研菌科RC9肠道群相对丰度显著高于CON组(P<0.05),CFA组瘤胃瘤胃球菌科UCG-014相对丰度显著高于其他组(P<0.05)。4)CFA组肝脏FA含量以及二氢叶酸还原酶(DHFR)和5,10-亚甲基四氢叶酸还原酶(MTHFR)mRNA相对表达量显著高于其他组(P<0.05),肝脏同型半胱氨酸含量显著低于其他组(P<0.05)。综上所述,补充CFA提高了奶牛泌乳性能,与瘤胃发酵和肝脏FA代谢的改善有关;补充CFA促进了瘤胃纤维分解菌的生长,补充135 mg/d FA促进了瘤胃淀粉分解菌的生长。
This experiment was conducted to investigate the effects of folic acid(FA)and coated folic acid(CFA)on lactation performance,rumen fermentation and hepatic FA metabolism in transition dairy cows.Eighty transition dairy cows with similar parity[(2.03±0.18)parities],body weight[(676.0±33.6)kg],milk production in the previous lactation period[(10155.0±256.2)kg]and expected delivery date were assigned in a randomized block design into 4 groups with 20 cows in each group.Cows in the control group(CON group)were fed a basal diet,while those in the experimental groups were fed the basal diets supplemented with 6.75 g/d CFA(contained 2%FA,CFA group),135 mg/d FA(LFA group)and 270 mg/d FA(HFA group),respectively.The experiment began from 35 days before calving,and the data and sample collection period was from 0 to 21 days after calving.The results showed as follows:1)the milk yield,4%fat-corrected milk yield,milk protein yield and feed efficiency in CFA group were significantly higher than those in CON group,LFA group and HFA group(P<0.05),and the milk fat yield was significantly higher than that in CON group and LFA group(P<0.05).2)Compared with CON group,the rumen FA content,the activities of superoxide dismutase(SOD)and glutathione peroxidase(GSH-Px),and the total volatile fatty acid(TVFA)content in CFA group,LFA group and HFA group were significantly increased(P<0.05),while the rumen malondialdehyde(MDA)content was significantly decreased(P<0.05).Meanwhile,compared with CFA group,the activities of rumen SOD and GSH-Px and the TVFA content in LFA group and HFA group were significantly increased(P<0.05),while the rumen MDA content and the acetate to propionate ratio were significantly decreased(P<0.05).3)There was no significant difference in the rumen microbiotaαdiversity indices among the groups(P>0.05).At the phylum level,the rumen Bacteroides relative abundance in LFA group was significantly higher than that in the other groups(P<0.05),while the rumen Firmicutes relative abundance was significantly lower than that in the other groups(P<0.05).At the genus level,the relative abundances of rumen uncultured_rumen_bacterium and Prevotellaceae_UCG-001 in LFA group was significantly higher than those in the other groups(P<0.05),the rumen Rikenellaceae_RC9_gut_group relative abundance in CFA group,LFA group and HFA group was significantly higher than that in CON group(P<0.05),and the rumen Ruminococcaceae_UCG-014 relative abundance in CFA group was significantly higher than that in the other groups(P<0.05).4)The hepatic FA content and the mRNA relative expression levels of dihydrofolate reductase(DHFR)and 5,10-methylenetetrahydrofolate reductase(MTHFR)in CFA group were significantly higher than those in the other groups(P<0.05),while the hepatic homocysteine content was significantly lower than that in the other groups(P<0.05).In conclusion,the supplementation of CFA can enhance the lactation performance in dairy cows,which is related to the improvement of rumen fermentation and liver FA metabolism;the supplementation of CFA can stimulate the growth of rumen cellulolytic bacteria,and the supplementation of 135 mg/d FA can stimulate the growth of rumen amylolytic bacteria.
作者
刘百峤
冯江
荆玉倩
孙楠
霍文婕
郭刚
刘强
王聪
LIU Baiqiao;FENG Jiang;JING Yuqian;SUN Nan;HUO Wenjie;GUO Gang;LIU Qiang;WANG Cong(College of Animal Science,Shanxi Agricultural University,Taigu 030801,China)
出处
《动物营养学报》
北大核心
2025年第9期5998-6008,共11页
CHINESE JOURNAL OF ANIMAL NUTRITION
基金
国家自然科学基金项目(32272824)
中央引导地方科技发展资金项目(YDZJSX2022A039)
山西省现代农业牛产业技术体系建设项目(2025CYJSTX13)。
关键词
包被叶酸
围产期奶牛
泌乳性能
瘤胃发酵
肝脏叶酸代谢
coated folic acid
transition dairy cows
lactation performance
rumen fermentation
hepatic folic acid metabolism
