Alteration of digestive tract microbiome in neonatal Holstein bull calves by bacitracin methylene disalicylate treatment and scours1

Abstract

The effects of bacitracin methylene disalicylate (BMD) and scours on the fecal microbiome, animal performance, and health were studied in Holstein bull calves. Holstein bull calves (n = 150) were obtained from a single source at 12 to 24 h of age. Bull calves were randomly assigned to 1 of 2 treatments including CON (no BMD; n = 75 calves) and BMD (n = 75 calves). Starting 3 d after arrival, BMD was added into milk replacer (0.5 g/feeding; twice daily) and fed to the calves for 10 consecutive d. No differences (P > 0.10) were observed in ADG for d 0 to 28 and d 0 to 56, DMI for d 0 to 28, d 29 to 56, and d 0 to 56, or G:F for d 0 to 28, d 29 to 56, and d 0 to 56; ADG for d 29 to 56 tended to increase (P < 0.10) for BMD-treated calves compared with controls. Fecal samples were collected from 15 scouring calves and 10 cohorts (nonscouring calves received on the same day and administered the same treatment as the scouring calves). Animal morbidity and fecal score did not vary between the 2 treatments. Mortality was not influenced by the treatments in the BMD administration period or throughout the experiment. Fecal samples were subjected to pyrotagged 454 FLX pyrosequencing of 16S rRNA gene amplicon to examine compositional dynamics of fecal microbes. Escherichia, Enterococcus, and Shigella had greater (P < 0.05) populations in the BMD group whereas Dorea, Roseburia, Fecalibacterium, Papillibacter, Collinsella, Eubacterium, Peptostreptococcus, and Prevotella were decreased (P < 0.05) by BMD treatment. Genus populations were also compared between scouring and nonscouring calves. Streptococcus was the only genus that had notable increase (P < 0.05) in fecal samples from scouring calves whereas populations of Bacteroides, Roseburia, and Eubacterium were markedly (P < 0.05) greater in nonscouring calves. These results show that BMD has the ability to alter the composition of the fecal microbiome but failed to improve performance in Holstein bull calves. Discrepancy of microorganism profiles between scouring and nonscouring calves might be associated with the occurrence of scours and bacterial genera identified might be potential target of treating diarrhea.

Tannins and Bacitracin Differentially Modulate Gut Microbiota of Broiler Chickens

“…Bacitracin is one of the most extensively used AGPs to improve productivity in poultry [ 1 ]. In calves, bacitracin has been shown to alter fecal microbiota composition but did not improve animal performance [ 28 ]. Some studies have reported alterations in the gut bacterial community of broiler chickens associated with dietary supplementation with bacitracin [ 17 , 29 ].…”

Temporal dynamics of the fecal microbiota in veal calves in a 6-month field trial

“…Moreover, literature on the effect of each antibiotic class on the hindgut microbiota of preweaned dairy calves is scarce. As far as we know, research on this topic has focused on a few classes: macrolides [7,24], tetracycline [7], amphenicol [7], uoroquinolones [24], and polypeptides [25]. These studies, with the exception of that by Xie et al [25], all focused on the effects of a single injection of the antibiotic, which differs from the treatment plans and route of administration (oral) in our study.…”

“…As far as we know, research on this topic has focused on a few classes: macrolides [7,24], tetracycline [7], amphenicol [7], uoroquinolones [24], and polypeptides [25]. These studies, with the exception of that by Xie et al [25], all focused on the effects of a single injection of the antibiotic, which differs from the treatment plans and route of administration (oral) in our study. Xie et al reported dysbiosis in neonatal dairy calves receiving bacitracin for 10 days in the milk replacer, characterized by an increase in the abundance of Escherichia and Enterococcus, along with a decrease in the abundance of Dorea, Collinsella, Eubacterium, Faecalibacterium, Papillibacter, Peptostreptococcus, Prevotella, and Roseburia, relative to non-exposed calves of the same age [25].…”

“…Antibiotic-induced loss of diversity has already been reported in young beef cattle [6], as well as preweaned calves [7], and was often found to be associated with the depletion of bene cial bacteria and/or the increase of opportunistic pathogens [7,25]. Antibiotic-induced dysbiosis is also observed when preweaned calves are fed low doses of antibiotic molecules [27].…”

Evaluation of the effects of colostrum replacer supplementation of the milk replacer ration on the occurrence of disease, antibiotic therapy, and performance of pre-weaned dairy calves

“…The use of antibiotics for the treatment of bovine respiratory disease and umbilical infection is a common practice among bovine practitioners (Shearer, 1986;Apley, 2015); however, the treatment of calf diarrhea with antimicrobials remains a controversial topic among veterinarians. The risk of bacteremia in diarrheic calves supports the use of antimicrobials in some cases (Fecteau et al, 1997); in contrast, the potential for causing disturbances on the intestinal microflora and increasing the risk of bacterial resistance discourages the use of antimicrobials in the treatment of calf diarrhea in other cases (Xie et al, 2013). In the present study, local and systemic protection provided by immunoglobulins and immunomodulatory molecules from the colostrum powder might have reduced the incidence of infection and therefore the need of antibiotic therapy in supplemented calves.…”