Document Type

Thesis - Open Access

Award Date

2019

Degree Name

Doctor of Philosophy (PhD)

Department / School

Dairy Science

First Advisor

Johan S. Osorio

Keywords

gastrointestinal tract, gene expression, health, microbiota, neonatal calves

Abstract

Physiological adaptations of the gastrointestinal tract (GIT) epithelial cells as well as methods to manipulate early life GIT microbiota colonization during the neonatal stage, is of great importance to the dairy industry. The first objective of this research was to optimize a method based on evaluation of bovine transcripts in fecal RNA via RTqPCR using L-selectin (SELL) as a marker for polymorphonuclear leukocytes (PMNL), keratin 8 (KRT8) and fatty acid binding protein 2 (FABP2) for GIT enterocytes, and tight junctions in fecal RNA and GIT sections in dairy calves. To test the reliability of the fecal RNA method, fecal and PMNL samples from neonatal calves were used. The expression of KRT8 was greater in fecal RNA than in PMNL. In contrast, a greater SELL expression was observed in PMNL. In another study, postmortem GIT and feces samples were collected from healthy calves for total RNA isolation. Overall, the expression of FABP2 and KRT8 was similar between fecal RNA and the lower GIT. Taken together, these results provide further evidence that the fecal RNA method can potentially be used as a tool to evaluate molecular adaptations of the GIT in dairy calves. The second objective was to evaluate the effects of early life fecal microbiota transplantation (FMT) from healthy adult donors on health and performance of neonatal dairy calves. To test the effects of FMT, newborn calves were subjected to 1×/d inoculations with 25 g of fecal donor material mixed in the milk replacer from 8 to 12 d of age. Results from this study demonstrated that calves subjected to FMT tended to have greater body weight than control calves. The liver function marker paraoxonase was greater in the blood of FMT calves than control at 3wk of age. These results suggest that FMT in neonatal calves has positive effects not only on growth performance but also in mediating liver function.

Library of Congress Subject Headings

Calves.
Dairy cattle.
Gastrointestinal system -- Microbiology.
Gene expression.
Neonatal diarrhea in cattle.

Format

application/pdf

Number of Pages

106

Publisher

South Dakota State University

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Rights Statement

In Copyright