The Bacterial Content of the Small Intestine of Young Calves

The Cattle Microbiota and the Immune System: An Evolving Field

New insights into the host-microbiota relationship have recently emerged with the advancement of molecular technologies such as next-generation sequencing. This article presents the current knowledge regarding the interaction between bacteria and the immune system of the gut, the uterus, and the mammary gland of cattle.

Characterization of the Fecal Bacterial Microbiota of Healthy and Diarrheic Dairy Calves

BACKGROUND

Neonatal diarrhea accounts for more than 50% of total deaths in dairy calves. Few population-based studies of cattle have investigated how the microbiota is impacted during diarrhea.

OBJECTIVES

To characterize the fecal microbiota and predict the functional potential of the microbial communities in healthy and diarrheic calves.

METHODS

Fifteen diarrheic calves between the ages of 1 and 30 days and 15 age-matched healthy control calves were enrolled from 2 dairy farms. The Illumina MiSeq sequencer was used for high-throughput sequencing of the V4 region of the 16S rRNA gene (Illumina, San Diego, CA).

RESULTS

Significant differences in community membership and structure were identified among healthy calves from different farms. Differences in community membership and structure also were identified between healthy and diarrheic calves within each farm. Based on linear discriminant analysis effect size (LEfSe), the genera Bifidobacterium, Megamonas, and a genus of the family Bifidobacteriaceae were associated with health at farm 1, whereas Lachnospiraceae incertae sedis, Dietzia and an unclassified genus of the family Veillonellaceae were significantly associated with health at farm 2. The Phylogenetic Investigation of Communities Reconstruction of Unobserved States (PICRUSt) analysis indicated that diarrheic calves had decreased abundances of genes responsible for metabolism of various vitamins, amino acids, and carbohydrate.

CLINICAL RELEVANCE

The fecal microbiota of healthy dairy calves appeared to be farm specific as were the changes observed during diarrhea. The differences in microbiota structure and membership between healthy and diarrheic calves suggest that dysbiosis can occur in diarrheic calves and it is associated with changes in predictive metagenomic function.

Surgical diseases of the small intestine

Surgical disorders of the gastrointestinal tract of cattle occur occasionally, and veterinarians are challenged to determine an accurate diagnosis and treatment for these conditions. Although surgical diseases most commonly occur in the forestomachs (dislocated abomasum, reticuloperitonitis) and the colons (cecal dilatation), this article focuses on lesions in the small intestine (duodenum, jejunum, ileum).

Intestinal surgery of adult cattle

Surgical disorders of the gastrointestinal tract of cattle occur occasionally, and veterinarians are challenged to determine an accurate diagnosis and treatment for these conditions. Although surgical diseases most commonly occur in the forestomachs (dislocated abomasum, reticuloperitonitis) and the colons (cecal dilation), this article focuses n lesions in the small intestine (duodenum, jejunum, ileum).

Effect of orally administered duodenal fluid susceptibility of newborn calves to an Escherichia coli challenge

This study was to determine if duodenal contents inoculated orally could alter symptomatic diarrhea produced by Escherichia coli [09:K(A)] in neonatal calves. Inoculum was obtained 2 h postprandially from duodenal-cannulated milk-fed calves. Thirty Holstein bull calves obtained within 3 h of birth were assigned alternately to a 3 X 2 factorial experiment. Calves received either 1) no E. coli challenge, 2) challenge at 12 h, or 3) challenge at 24 h each with or without 200 ml duodenal fluid orally with the first feeding of colostrum. Rectal temperature, urine output, milk intake, and fecal dry matter were recorded daily, and body weight and hematocrit every 3rd day for 1 wk. Gamma globulin of serum was determined at 2 h of age. Inocula and duodenal tissue and fluid of the last 12 calves were assayed for total anaerobic bacterica, anaerobic and aerobic lactobacilli, coliforms, and total aerobic bacteria. Inoculated calves exhibited lower incidence of diarrhea, greater urine output, lower hematocrit, and superior average daily gain as compared to uninoculated calves. Concentration of gamma globulin in serum of inoculated calves was subnormal. Bacterial populations of tissue and fluid at 7 days were not influenced by treatment.