Wu Yanyan, Wang Lili, Luo Ruiqing, Chen Hongli, Nie Cunxi, Niu Junli, Chen Cheng, Xu Yongping, Li Xiaoyu, Zhang Wenjun
College of Animal Science and Technology, Shihezi University, Shihezi, China.
School of Bioengineering, Dalian University of Technology, Dalian, China.
Front Microbiol. 2021 Jul 14;12:681014. doi: 10.3389/fmicb.2021.681014. eCollection 2021.
The effects of different doses of a multispecies probiotic (MSP) mixture on growth performance, the incidence of diarrhea rate and immune function, and fecal microbial diversity and structure were evaluated in pre-weaning Holstein dairy calves at WK2, WK4, WK6, and WK8. Forty Chinese Holstein female newborn calves were randomly assigned to four treatments with 10 calves in each group, C (control group), T1 (0.5 g MSP/calf/day, T2 (1 g MSP/calf/day), and T3 (2 g MSP/calf/day) groups. The experimental period was 56 days. Feed intake and health scoring were recorded every day until the end of the experiment. Fecal contents and blood samples were sampled at WK2, WK4, WK6, and WK8. Growth performance, incidence of diarrhea, and total serum concentrations (IgA, IgG, and IgM) were analyzed. Bacterial 16S rRNA and fungal ITS genes were high-throughput sequenced for fecal microbiota. The relationships among the populations of the principal fecal microbiota at WK2 and the growth performance or serum immunoglobulin concentrations were analyzed using Pearson's rank correlation coefficients. The MSP supplementation reduced the incidence of diarrhea in the first 4 weeks of life, and serum IgA, IgG, and IgM concentrations increased between WK2 and WK8 in the T3 group. There was an increase in growth performance and reduction in the incidence of diarrhea until WK4 after birth in T3 group, compared with the control, T1, and T2 groups. The results of fecal microbiota analysis showed that and were the predominant phyla, with , , , , , and being the dominant genera in calf feces. , , and s were the predominant fungal phyla. Compared with the control, in T1 and T2 groups, the MSP supplementation reduced the relative abundance of s and increased the relative abundance of , , , and at WK2 in group T3. Thus, the fecal microbial composition and diversity was significantly affected by the MSP mixture during the first 2 weeks of the calves' life. MSP mixtures reduced the incidence of diarrhea in pre-weaning calves (during the first 4 weeks of life). There was a significant improvement in growth performance, reduction in calf diarrhea, balance in the fecal microbiota, and an overall improvement in serum immunity, compared with the control group. We, therefore, recommend adding 2 g/day of multispecies probiotic mixture supplementation in diets of dairy calves during their first 4 weeks of life before weaning.
在2周龄、4周龄、6周龄和8周龄时，评估了不同剂量的多物种益生菌（MSP）混合物对断奶前荷斯坦奶牛犊牛生长性能、腹泻率和免疫功能发生率以及粪便微生物多样性和结构的影响。40头中国荷斯坦雌性新生犊牛被随机分为四组，每组10头，分别为C（对照组）、T1（0.5 g MSP/犊牛/天）、T2（1 g MSP/犊牛/天）和T3（2 g MSP/犊牛/天）组。实验期为56天。每天记录采食量和健康评分，直至实验结束。在2周龄、4周龄、6周龄和8周龄时采集粪便内容物和血样。分析生长性能、腹泻发生率和血清总浓度（IgA、IgG和IgM）。对粪便微生物群的细菌16S rRNA和真菌ITS基因进行高通量测序。使用Pearson等级相关系数分析2周龄时主要粪便微生物群数量与生长性能或血清免疫球蛋白浓度之间的关系。补充MSP降低了犊牛出生后前4周的腹泻发生率，T3组在2周龄至8周龄期间血清IgA、IgG和IgM浓度升高。与对照组、T1组和T2组相比，T3组出生后至4周龄时生长性能提高，腹泻发生率降低。粪便微生物群分析结果表明， 和 是主要的门， 、 、 、 、 和 是犊牛粪便中的优势属。 、 和 是主要的真菌门。与对照组相比，在T1组和T2组中，补充MSP降低了 的相对丰度，在T3组2周龄时增加了 、 、 和 的相对丰度。因此，在犊牛出生后的前2周内，MSP混合物显著影响了粪便微生物组成和多样性。MSP混合物降低了断奶前犊牛（出生后前4周）的腹泻发生率。与对照组相比，生长性能显著改善，犊牛腹泻减少，粪便微生物群平衡，血清免疫力总体提高。因此，我们建议在奶牛犊牛断奶前的前4周内，在其日粮中添加2 g/天的多物种益生菌混合物。
