|Butler, W -|
Submitted to: Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: June 28, 2010
Publication Date: July 9, 2010
Citation: Waterman, R.C., Butler, W.R. 2010. Metabolic signals of the beef cow in negative energy balance. Fourth Grazing Livestock Nutrition Conference Proceedings. Estes Park CO convention center, July 9–10, 2010. Interpretive Summary: Extensive beef cattle enterprises endure difficulties trying to maintain beef cow production that is both sustainable and profitable. Furthermore, beef cow production on arid and semiarid rangelands is directly influenced by environmental conditions (i.e., forage quantity and quality available for consumption). To achieve optimal levels of production, harvested and purchased feedstuffs are often fed to range cows to supplement periods of nutritional stress. The cost of delivering these feedstuffs to range cows is one of the largest input costs a producer will encounter. However, the range beef cow still must perform by being reproductively and biologically efficient within these changing environments. Under these demanding circumstances, beef cows experience similar metabolic dysfunctions as observed in high producing dairy cows following parturition; however seasonal changes in forage quality play a larger role in inducing metabolic dysfunction throughout the production cycle of beef cows than that occurring around parturition. The purpose of this proceeding will be to expand the topic of negative energy balance that occurs around parturition and/or early lactation to include the entire production cycle of the beef cow.
Technical Abstract: In extensive western livestock production systems, timing and amount of precipitation are crucial in spring through early summer for establishment of cool-season grasses. Furthermore, as summer progresses, temperatures increase while precipitation decreases, followed by decreases in forage quality that continue through fall and winter, thus negatively impacting livestock production. Studies have demonstrated that varying concentrations of glucogenic precursors fed to postpartum range cows consuming supplements containing can influence nutrient partitioning. Supplements higher in glucogenic precursors minimize maternal catabolism, as well as, allow partitioning of dietary nutrients toward maternal tissue. As a result, rates of glucose sequestration into maternal tissues can be modified. If nutritional stresses that render maternal tissues less responsive to actions of insulin can be identified, then metabolically targeted strategic supplementation regimes may minimize these effects. Seasonal alterations in glucose metabolism (i.e., oxidative metabolism) as influenced by tissue responsiveness to insulin in beef cows grazing rangelands in the Northern Great Plains occur in relation to forage quality. Altered glucose metabolism may ultimately affect physiological performance and reproductive function in range beef cow.