Project description:We functionally analyzed the rumen epithelial transcriptomes from low- and high- feed efficient beef steers to identify differences that might contribute to variation in feed efficiency.
Project description:The potential for dietary supplementation with n-3 polyunsaturated fatty acids (n-3 PUFA) to improve reproductive efficiency in cattle has received much interest. The mechanisms by which n-3 PUFA may affect physiological and biochemical processes in key reproductive tissues are likely to be mediated by significant alterations in gene expression. We used microarrays to assess endometrial gene expression on day 17 of the estrous cycle in n-3 PUFA compared with control fed heifers. Beef heifers were supplemented with a rumen protected source of either a saturated fatty acid (CON; palmitic acid) or high n-3 PUFA (n-3 PUFA; 275 g) diet per animal per day for 45 days and global gene expression was determined in uterine endometrial tissue using an Affymetrix® oligonucleotide bovine array.
Project description:The objective of our study was to assess the effect of rumen-protected niacin supplementation on the overall transcriptomics profile of liver tissue on growing Angus × Simmental steers and heifers. Consequently, the vasodilatory, detoxifying, and immune suppressor effects of niacin were evaluated in hepatocytes. After a 30-day supplementation period with rumen-protected niacin on normal weaned beef calves, we observed a significant list of benefits at the liver transcriptome level. Several metabolic pathways revealed positive effects of administration of rumen-protected niacin; for example, a decrease in lipolysis, apoptosis, inflammatory responses, atherosclerosis, oxidative stress, fibrosis, and vasodilation-related pathways. Therefore, results from this study could potentially promote supplementation of rumen-protected niacin on beef cattle backgrounding operations or new arrivals to a feedlot, especially during the acclimation period when the health status of growing beef cattle is usually compromised.
Project description:The selection of cattle with high feed efficiency is of paramount importance with regard to reducing feed costs in the beef industry. Developing predictive biological markers specifically for improved feed efficiency is an attractive alternative to direct measurement on large numbers of animals.Evidence is provided that, effects of RFI on gene expression in muscle of beef cattle are not consistent across breed type or dietary phase. These novel observations challenge the practicality of selecting and breeding for low RFI animals across different diets and stages of development. Perhaps, future research should be directed at utilising different diets to harness the full genetic potential of animal based on breed or stage of maturity. Further to this, evidence is provided from our own work and that of others that less efficient HF steers consuming zero grazed grass are under increased stress as demonstrated by an upregulation of immune function in these animals.
