Dynamic Changes in Fecal Microbial Communities of Neonatal Dairy Calves by Aging and Diarrhea

Abstract

Microbiota plays a critical role in the overall growth performance and health status of dairy cows, especially during their early life. Several studies have reported that fecal microbiome of neonatal calves is shifted by various factors such as diarrhea, antibiotic treatment, or environmental changes. Despite the importance of gut microbiome, a lack of knowledge regarding the composition and functions of microbiota impedes the development of new strategies for improving growth performance and disease resistance during the neonatal calf period. In this study, we utilized next-generation sequencing to monitor the time-dependent dynamics of the gut microbiota of dairy calves before weaning (1–8 weeks of age) and further investigated the microbiome changes caused by diarrhea. Metagenomic analysis revealed that continuous changes, including increasing gut microbiome diversity, occurred from 1 to 5 weeks of age. However, the composition and diversity of the fecal microbiome did not change after 6 weeks of age. The most prominent changes in the fecal microbiome composition caused by aging at family level were a decreased abundance of Bacteroidaceae and Enterobacteriaceae and an increased abundance of Prevotellaceae. Phylogenetic investigation of communities by reconstruction of unobserved states (PICRUSt) analysis indicated that the abundance of microbial genes associated with various metabolic pathways changed with aging. All calves with diarrhea symptoms showed drastic microbiome changes and about a week later returned to the microbiome of pre-diarrheal stage regardless of age. At phylum level, abundance of Bacteroidetes was decreased (p = 0.09) and that of Proteobacteria increased (p = 0.07) during diarrhea. PICRUSt analysis indicated that microbial metabolism-related genes, such as starch and sucrose metabolism, sphingolipid metabolism, alanine aspartate, and glutamate metabolism were significantly altered in diarrheal calves. Together, these results highlight the important implications of gut microbiota in gut metabolism and health status of neonatal dairy calves.

Early Life Fecal Microbiota Transplantation in Neonatal Dairy Calves Promotes Growth Performance and Alleviates Inflammation and Oxidative Stress during Weaning

“…In contrast, the gut of healthy adult subjects is composed of a minor proportion of this facultative anaerobic bacteria [ 61 ]. Recently, a longitudinal evaluation of the fecal microbial communities (from birth to 8 weeks of age) in dairy calves with diarrhea reported a greater abundance of Enterobacteriaceae in the feces of diarrheic calves relative to the control [ 62 ]. In the current study, the lower relative abundance of Enterobacteriaceae post-FMT in the feces of recipient’s calves at week 5 suggests that FMT may modulate gut microbial composition in early life.…”

Gut Microbial Alterations in Diarrheal Baer's Pochards (Aythya baeri)

“…When the balance of gut microbiota is broken, the pathogenic microbes and their toxins increase relatively, which will damage the intestinal mucosa barrier, increase its permeability. Intestinal pathogenic microbes and their antigens can activate mast cells, and the sensitized mast cells can release histamine, serotonin, prostaglandin, trypsin, and other active substances to enhance smooth muscle contraction, increase intestinal peristalsis, and eventually result in diarrhea (43,44). Moreover, long-term diarrhea can further aggravate gut microbial dysbiosis and diarrhea.…”

Effects of Multispecies Probiotic on Intestinal Microbiota and Mucosal Barrier Function of Neonatal Calves Infected With E. coli K99

“…Older calves have a higher Chao1 index (Oikonomou et al, 2013). Diarrhea or an infection may cause a decrease in microbial diversity (Kim et al, 2021;Xin et al, 2021). While most previous studies focused on investigating and interpreting calf manure samples, only a relatively few studies, such as ours, have focused on investigating the effects of feeding calves with compound probiotics on the intestinal microflora of these animals.…”