Assistant Professor North Carolina State University Raleigh, North Carolina, United States
Abstract: Background The impact of colostrum type on early gut colonization in newborn calves is not well understood. Objectives To compare the microbiota profiles of bovine colostrum replacer (CR) and maternal colostrum (MC) and to compare fecal microbiota development in healthy newborn calves fed CR or MC. Animals 28 Holstein heifer calves Methods Randomized controlled trial. Calves received either 5 L of MC from their own dam or 4.8 L of a CR, both administered in two feedings within the first 6 hours of life. MC and CR samples were collected at each feeding, and fecal swabs were obtained at 0, 24 hours, and 7 days of age. Samples were frozen at −80°C prior to DNA extraction and 16S rRNA gene amplicon sequencing. Alpha (Shannon index) and beta diversity (Bray–Curtis dissimilarity) were compared between groups with Wilcoxon rank sum test or PERMANOVA. Results Alpha diversity differed between CR (n=15) and MC (n=13, P < 0.0002), with greater microbial variability observed in MC. Fecal alpha diversity did not differ between groups at any time point (P > 0.2). A significant time-by-treatment effect was observed for fecal beta diversity, with differences between calves that received CR or MC at 24 hours (P = 0.003), where multiple genera were differentially abundant (FDR-adjusted P < 0.05). Taxa driving community differences in calf feces were not the most abundant colostrum-associated taxa. Conclusions and Clinical Importance Colostrum type temporarily and indirectly influences neonatal fecal microbiome assembly, likely through modification of gut conditions rather than direct microbial transfer.
Learning Objectives:
Upon completion, participants will be able to explain foundational microbiome concepts, including alpha diversity (e.g., Shannon index) and beta diversity (e.g., Bray–Curtis dissimilarity), and apply these metrics to interpret study findings.
Upon completion, participants will be able to describe the microbiome differences between maternal colostrum and colostrum replacer.
Upon completion, participants will be able to describe the temporal development of the fecal microbiome in newborn calves during the first week of life, and evaluate the effects of colostrum source on this process.
Upon completion, participants will be able to identify the clinical implications of colostrum source on neonatal calf health.
