1a.Objectives (from AD-416):
Elucidate adaptive mechanisms that promote energy efficiency in the range beef cow. Various measurements exposing physiological/metabolic changes will be evaluated based on their genetic origins.
1b.Approach (from AD-416):
Cows and their daughter have been developed and managed based upon a factorial approach to prenatal and post natal nutritional management. Production, physiological and metabolic measurements will be used to assess cow longevity (based on reproductive rate) and economic efficiency. Microarray analysis will be implemented to establish the association between genetic background and important traits related to stress adaption.
Final report for the SCA between New Mexico State University and the USDA-ARS Ft. Keogh Research Station entitled “Range cow adaptive mechanisms to stressors: Genetic metabolic and behavioral” progressed as planned. This research has been focused on elucidating the adaptive mechanisms that promote energy efficiency in grazing beef cows and metabolic indicators for improving and predicting reproductive efficiency. Work was conducted to develop a chute-side test to identify beef heifers and cows that either have a low likelihood of achieving pregnancy or increased probability of a delayed pregnancy in a fixed breeding season due to metabolic dysfunctions. This metabolic dysfunction is the result from poor adaptation to negative energy balance after calving. These studies indicate that certain blood metabolites are related to or may have a detrimental effect on the interval of resumption of estrus in young beef cows and thereby prolong time of conception. Both New Mexico State University and Ft. Keogh worked closely on the completion of this research. Abbott Laboratories, the manufacturer of the handheld meter used in this research, has shown an interest in the findings of this effort and is reviewing the potential of future support to bring this technology for use in practical production settings. One doctoral student was supported by this SCA. This work produced one dissertation and three published accepted peer-reviewed manuscripts (see parent project).