346 - Feeding Hempseed Cake Alters the Bovine Gut, Respiratory and Reproductive Microbiota

Monday, June 27, 2022

3:05 PM – 3:20 PM CT

Location: Oklahoma City Convention Center, 206 A/B

Author(s)

Thomas Winders

Graduate Research Assistant
North Dakota State University
Fargo, North Dakota
DH

Devin Holman

Research Scientist
Agriculture Agri-Food Canada, Lacomb Research and Development Center
Lacombe, AB
KS

Kaycie Schmidt

Research Specialist
North Dakota State University
Fargo, ND
DS

David J. Smith

Research Leader
USDA ARS-ETSARC
Fargo, ND
Bryan W. Neville, n/a

Research Animal Scientist
Carrington REC - Carrington, ND
Clay Center, NE
CD

Carl R. Dahlen, PhD

Associate Professor
North Dakota State University
Fargo, North Dakota
Kendall C. Swanson

Professor
North Dakota State University
Fargo, ND

Presenting Author(s)

Samat Amat, n/a

Assistant Professor
North Dakota State University
Fargo, ND

Abstract: A growing number of studies have investigated the viability of feeding hemp by-products as livestock feedstuffs; however, their impact on livestock microbiomes remains unexplored. Here, we evaluated the effects of feeding hempseed cake (HSC) on the gastrointestinal, respiratory, and reproductive microbiota in beef heifers. Angus-crossbred heifers [19-months old; initial body weight (BW) = 494 ± 10 kg] were fed a corn-based finishing diet (10% forage) containing either 20% HSC (n = 15) or 20% corn distillers grains (Control, n = 16) for 111 days until slaughter. Individual feed intake, feeding behavior and BW were measured throughout the study. Rumen fluid and deep nasopharyngeal swabs (days 0 7, 42, 70 and 98), and vaginal and uterine swabs (at slaughter) were collected, and the microbiota assessed using 16S rRNA gene sequencing. HSC feeding resulted in reduced average daily gain (P = 0.05) without influencing feed intake and feeding behavior (P > 0.05) (reported elsewhere). Sampling time had a significant effect on both ruminal (PERMANOVA: R² = 0.39; P < 0.001) and nasopharyngeal (R²= 0.18; P < 0.001) microbial community structure. There was also a significant effect of diet on the ruminal (d7– 98; 0.06 ≤ R²≤ 0.12; P < 0.05), nasopharyngeal (d 42; R²= 0.18; P < 0.001), and vaginal (R² = 0.06; P < 0.01) microbiota. Although microbial richness in the rumen, nasopharynx, vagina, and uterus was not affected (P > 0.05) by HSC feeding, microbial diversity (Shannon diversity) was increased in the rumen (d42-98) but reduced in the uterus of HSC heifers (P < 0.05). The relative abundance of five ruminal genera was enriched, while five vaginal genera were reduced in HSC heifers (P < 0.05). Overall, the results of our longitudinal study suggest that feeding hemp by-products can alter the bovine gut, respiratory and reproductive microbiota.