母带犊牛与离母犊牛的血清代谢组学差异

Serum Metabolomic Differences between Calves with Dam and Calves without Dam

本试验旨在比较母带犊牛和离母犊牛的血清代谢组学差异,为开发犊牛代乳粉提供方向。挑选8头健康且体重[(13.88±0.54) kg]接近的新生犊牛(牦牛♂×犏牛♀)为母带犊牛组,犊牛随母哺乳;另外挑选8头体重[(13.75±0.82) kg]接近的新生犊牛(牦牛♂×犏牛♀)为离母犊牛组,犊牛饲喂代乳粉。2组犊牛10 d后自由采食相同饲粮。试验期90 d。试验结束当天晨饲前对2组犊牛进行采血,采用超高效液相色谱-四极杆飞行时间质谱(UPLC-QTOF/MS)对血清样品进行代谢组学分析。以差异倍数(FC)、变量重要性投影(VIP)和t检验P值作为筛选依据,筛选标准为FC<0.5或FC>1.5、VIP>1和P<0.01。结果表明,共筛选出DL-3苯乳酸、D-山梨糖醇和橙皮素等共30个差异代谢物(FC<0.5或FC>1.5、VIP>1和P<0.01)。差异代谢物通路分析表明,与血清代谢物的改变最为相关的是D-谷氨酰胺和D-谷氨酸代谢、牛磺酸和亚牛磺酸代谢、精氨酸和脯氨酸的代谢、乙醛酸和二羧酸代谢以及谷胱甘肽代谢5条代谢通路。离母犊牛血清中具有抑菌作用的物质如DL-3-苯乳酸、月桂酸和L-苹果酸以及抗氧化功能物质如γ-谷氨酰半胱氨酸、L-谷氨酸和牛磺酸等含量显著低于母带犊牛(FC<0.5或FC>1.5、VIP>1和P<0.01)。离母犊牛脂肪分解代谢增强,血清中非酯化脂肪酸如硬脂酸、二十酸和二十一烷酸含量显著高于母带犊牛(FC<0.5或FC>1.5、VIP>1和P<0.01)。此外,离母犊牛血清中胆固醇和萜类化合物合成的重要中间产物甲羟戊酸含量显著低于母带犊牛(FC<0.5或FC>1.5、VIP>1和P<0.01)。由此可见,饲喂代乳粉的离母犊牛的抗菌、抗氧化能力弱于母带犊牛;脂肪代谢分解能力强于母带犊牛,脂肪合成代谢能力弱于母带犊牛。

This experiment was conducted to compare the serum metabolomic differences between calves with dam and calves without dam,and to provide a direction for the development of calf milk replacer. Eight healthy newborn calves(yak ♂×Pian cattle♀)with similar body weight[(13.88±0.54)kg]were selected as the calves with dam group,and calves suckled with heifers;another eight healthy newborn calves(yak ♂×Pian cattle♀)with similar body weight[(13. 75 ± 0. 82)kg]were selected as calves without dam group,and calves fed the milk replacer. Calves in 2 groups were free feeding the same diet after 10 days. The experiment lasted for 90 days. The blood samples of calves in 2 groups were collected before morning feeding on the day of test completion,the metabolomics analysis was performed on the serum samples using ultrahigh performance liquid chromatography/quadrupole time of flight mass spectrometry(UPLC-QTOF/MS). The fold change(FC),variable importance in projection(VIP)and P-value of the t-test were used as the screening basis,and the screening criteria were FC<0.5 or FC>1.5,VIP>1 and P<0.01. The results showed as that a total of 30 significant metabolics such as DL-3 phenyllactic acid,D-sorbitol and hesperidin were screened(FC < 0.5 or FC>1.5,VIP>1 and P<0.01). The pathways of significant metabolites analysis showed that the 5 metabolic pathways of D-glutamine and D-glutamate metabolism,taurine and hypotaurine metabolism,arginine and proline metabolism,glyoxylate and dicarboxylate metabolism and glutathione metabolism were the most correlated pathway with the changes of serum metabolites. The contents of antibacterial substances such as DL-3-phenyllactic acid,lauric acid and L-malic acid and antioxidant substances such asγ-glutamylcysteine,L-glutamate and taurine etc in serum of calves without dam were significantly lower than those of calves with dam(FC<0.5 or FC>1.5,VIP>1 and P<0.01). The lipocatabolism was enhanced of calves without dam,and the contents of non-esterified fatty acids such as stearic acid,eicosicanoic acid and icosenicanoic acid in serum were significantly higher than those of calves with dam(FC<0.5 or FC>1.5,VIP>1 and P<0.01). In addition,the content of mevalic acid in serum,an important intermediate in the synthesis of cholesterol and terpenoids,was significantly lower of calves without dam than that of calves with dam(FC<0.5 or FC>1.5,VIP> 1 and P <0.01). In conclusion,the antibacterial and antioxidant capacities of calves without dam feeding milk replacer are weaker than those of calves with dam;the fat catabolism capacity is better than that of calves with dam,and the fat anabolism is weaker than that of calves with dam.[Chinese Journal of Animal Nutrition,2022,34(2):1109-1118]