Effects of different types of zinc supplement on the growth, incidence of diarrhea, immune function, and rectal microbiota of newborn dairy calves

Abstract

Neonatal diarrhea in dairy calves causes huge economic and productivity losses in the dairy industry. Zinc is an effective anti-diarrheal agent, but high doses may pose a threat to the environment. Therefore, we aimed to evaluate the effects of low-dose zinc supplementation on the growth, incidence of diarrhea, immune function, and rectal microbiota of newborn Holstein dairy calves. Thirty newborn calves were allocated to either a control group (without extra zinc supplementation), or groups supplemented with either 104 mg of zinc oxide (ZnO, equivalent to 80 mg of zinc/d) or 457 mg of zinc methionine (Zn-Met, equivalent to 80 mg of zinc/d) and studied them for 14 d. The rectal contents were sampled on d 1, 3, 7, and 14, and blood samples were collected at the end of the study. Supplementation with ZnO reduced the incidence of diarrhea during the first 3 d of life, and increased serum IgG and IgM concentrations. The Zn-Met supplementation increased growth performance and reduced the incidence of diarrhea during the first 14 d after birth. The results of fecal microbiota analysis showed that Firmicutes and Proteobacteria were the predominant phyla, and Escherichia and Bacteroides were the dominant genera in the recta of the calves. As the calves grew older, rectal microbial diversity and composition significantly evolved. In addition, dietary supplementation with ZnO reduced the relative abundance of Proteobacteria in 1-d-old calves, and increased that of Bacteroidetes, Lactobacillus, and Faecalibacterium in 7-d-old calves, compared with the control group. Supplementation with Zn-Met increased the relative abundance of the phylum Actinobacteria and the genera Faecalibacterium and Collinsella on d 7, and that of the genus Ruminococcus after 2 wk, compared with the control group. Thus, the rectal microbial composition was not affected by zinc supplementation but significantly evolved during the calves' early life.Zinc supplementation reduced the incidence of diarrhea in young calves. In view of their differing effects, we recommend ZnO supplementation for dairy calves during their first 3 d of life and Zn-Met supplementation for the subsequent period. These findings suggest that zinc supplementation may be an alternative to antibacterial agents for the treatment of newborn calf diarrhea.

Effect of the Source of Zinc on the Tissue Accumulation of Zinc and Jejunal Mucosal Zinc Transporter Expression in Holstein Dairy Calves

“…Furthermore, the incidence of diarrhea was significantly lower in the Zn-Met group than in the CON group from the second week after birth, as reported previously [14,15]. Considering that the first two weeks of life is when the prevalence of diarrhea peaks in calves, we have recommended Zn-Met supplementation of the diet for dairy calves during early life because this could reduce the incidence of diarrhea [7]. Feldmann et al [8] also demonstrated that calves whose feed was supplemented with Zn-Met had a 14.7% lower risk of diarrhea than non-supplemented calves.…”

“…We previously evaluated the optimal dose of zinc for neonatal calves and showed that 80 mg zinc, in the form of ZnO, has the potential to alleviate newborn calf diarrhea [6]. In a subsequent study, we compared the effects of the same dose of zinc, provided in organic or inorganic form, on the growth and incidence of diarrhea in dairy calves, and showed that a low dose of zinc methionine (Zn-Met) or ZnO can ameliorate diarrhea in young calves, which is not the result of effects on rectal microbial composition or diversity [7].…”

Effect of a Multispecies Probiotic Mixture on the Growth and Incidence of Diarrhea, Immune Function, and Fecal Microbiota of Pre-weaning Dairy Calves

“…The primer sequences for the amplification of bacterial V3-V4 region are: F: 5 -ACTCCTACGGGAGGCAGCAG-3 and R: 5 -GGACTACHVGGGTWTCTAAT-3 (Chang et al, 2020). PCR conditions were as follows: 95 • C for 3 min; 35 cycles at 95 • C for 30 s, 55 • C for 30 s, and 72 • C for 45 s, followed by a hold at 72 • C for 10 min.…”

Establishment of a Newborn Lamb Gut-Loop Model to Evaluate New Methods of Enteric Disease Control and Reduce Experimental Animal Use

“…To promote gut health and improve growth, supplements containing immunoglobulins or mineral and vitamin complements, or with probiotics such as Enterococcus faecium can be orally given to young ruminants just after birth [ 22 , 23 , 24 ]. Live yeast and yeast-derived products are also extensively used as probiotic and prebiotic, respectively, for farm animals to reduce the severity of diarrhea by preventing pathogenic bacteria from binding to intestinal epithelial cells or by modulating gut mucosal immunity [ 25 , 26 , 27 ].…”