Location: Nutrition, Growth and PhysiologyTitle: Transcriptome profiles of the skeletal muscle of mature cows during feed restriction and realimentation
|CUNNINGHAM-HOLLINGER, H - University Of Wyoming|
|CAMMACK, K - South Dakota State University|
|Hales Paxton, Kristin|
Submitted to: BMC Research Notes
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/23/2021
Publication Date: N/A
Interpretive Summary: Grazing beef cow production herds can experience lower abundance and/or lower quality forage followed by periods of higher nutrient availability during the year. Realimentation is an increase in nutrients and is often used to compensate for periods of weight loss. Cows during realimentation vary in weight gains during this process and the purpose of this study was to determine the biological processes involved in cows that showed higher body weight gain during realimentation. Mature cows were fed a nutrient restricted diet followed by a period of ad libitum feed and muscle tissue was evaluated for differences in gene expression between cows with greater and lesser body weight gains. Results from the study identified biological pathways that underlie weight gain during times of abundance of feed after a restricted diet. The pathways critical to readjustment to an abundance of feed included oxidative stress and lipid metabolism pathways. However, there were pathways with altered expression unique to both higher and lower gaining animals. Higher gaining cows also employed additional energy pathways and lower gaining animals showed increased cell signaling pathways. These data provide a basis for continued work to identify key genes and associated biological functions in the muscle tissue associated with divergence in weight gain in beef cows. The ability to identify animals that will respond with greater compensatory gain upon refeeding will help producers improve production efficiencies and ensure animal health and well-being based on nutrient availability.
Technical Abstract: Objective: Realimentation can compensate for weight loss from poor-quality feedstuffs or drought. Mature cows fluctuate in body weight throughout the year due to nutrient availability. The objective of this study was to determine whether cows that differ in weight gain during realimentation also differ in the abundance of transcripts for enzymes associated with energy utilization in skeletal muscle. Mature cows were subjected to feed restriction followed by ad libitum feed. Skeletal muscle transcriptome expression differences during the two feeding periods were determined from cows with greater (n=6) and less (n=6) weight gain during the ad libitum feeding period. Results: A total of 567 differentially expressed genes (408 up- and 159 down-regulated) were identified for the comparison of restriction and ad libitum periods (PBonferroni<0.05). These genes were over-represented in lysosome, aminoacyl-tRNA biosynthesis, and glutathione metabolism pathways. Validation of the expression of five of the genes was performed and four were confirmed. These data suggest that realimentation weight gain for all cows is partially controlled by protein turnover, but oxidative stress and cellular signaling pathways are also involved in the muscle tissue. This dataset provides insight into molecular mechanisms utilized by mature cows during realimentation after a period of low abundance feed.