Diego Martinez Mayorga | ALES Graduate Seminar

Event details: A graduate exam seminar is a presentation of the student’s final research project for their degree.
This is an ALES MSc Final Exam Seminar by Diego Martinez Mayorga. This seminar is open to the general public to attend.

MSc with Dr. Anne Laarman.

Zoom Link: https://ualberta-ca.zoom.us/j/96202379666

Thesis Topic: Effects of protected and unprotected butyrate supplementation on growth performance, blood parameters, fermentation profile and gut histomorphometry in dairy calves.

Abstract: 

Calf gut growth and development are essential building blocks to produce healthy, lactating cattle. Butyrate is known to promote calf gut growth performance, but uncertainty persists on whether butyrate is more effective when unprotected, targeting the rumen, or protected, targeting the small intestine. The objective of this study was to evaluate rumen-protected and -unprotected butyrate supplementation on calf growth performance, gut fermentation profiles, gut histomorphology and plasma metabolites.

Calves (n = 36) were fed MR at 900 g/d and fed calf starter and water ad libitum. Animals were blocked by body weight, breed, and sex, and then assigned to one of three starter treatments: 1) Control, with 1% w/w palm fat as a placebo carrier (CON); 2) 1% w/w rumen-protected butyrate (2.5% of product; PRO); or 3) 1% w/w rumen-unprotected butyrate (1.5% of product) + 1% w/w palm fat (UNP). Calves were weaned via a two-stage stepdown from d 49 to 63 of age and were slaughtered at 70 d of age. Feed intake was measured daily; blood and body weight were sampled weekly. Feces and rumen fluid were sampled at 28, 42, 56 and 70 d of age; gastrointestinal digesta and tissues were collected at slaughter.

CON and PRO had higher BW than UNP (P < 0.01). There were no treatment differences in calf starter intake or feed efficiency. In the rumen, total SCFA concentration was not affected by treatment, but CON had a higher acetate proportion than PRO and UNP (P < 0.01), and UNP had a higher butyrate proportion than CON and PRO (P = 0.01). In the ileum, CON had a lower proportion of acetate (P = 0.05) and tended to have a higher proportion of propionate (P = 0.08) compared to PRO and UNP. Plasma βHBA and glucose concentrations were not affected by treatment, but UNP had lower post-weaning plasma urea nitrogen concentrations than PRO (P < 0.01) and CON (P = 0.09). PRO had longer ruminal papillae than CON ((P = 0.08) and UNP (P < 0.01) and PRO and CON both had wider papillae (P < 0.01) and with a greater surface area (P = 0.01) than UNP. UNP had the longest duodenal villi (P < 0.01) and villi to crypt ratio (P < 0.01) compared to PRO and CON. CON tended to have wider villi than PRO (P = 0.08). UNP had the longest villi in the distal jejunum (P = 0.05) and tended to have the widest villi in the jejunum (P = 0.09) compared to CON and PRO.

Body weight, rumen morphological development and protein metabolism was negatively affected by UNP while small intestine architecture was enhanced by UNP. Rumen-unprotected butyrate supplementation influenced ruminal fermentation dynamics, with fewer effects observed in the lower gut. Rumen-protected butyrate supplementation had no effects on calf performance but impacted rumen morphology positively. Further investigation is warranted on the different physiological effects of butyrate in growing calves as well as intestinal compensation mechanisms.