- Animal Products: dairy
- Animal Production: preventive practices
- Education and Training: extension, mentoring, on-farm/ranch research, workshop
Periparturient dairy cows lose weight due to reduced energy intake and increased energy expenditure. Overfeeding cows during late gestation results in excessive weight gain and adiposity (i.e. overconditioning) leading to the development of an “overnutrition syndrome”, similar to overweight monogastrics. Compared to lean cows, overconditioned cows exhibit greater insulin resistance and lipolysis resulting in elevated blood nonesterified fatty acid (NEFA) levels that predispose them to postpartum metabolic disease (PMD); compromising milk production, fertility, and health. Approaches to monitor pre-onset insulin resistance and hyperlipidemia represent a new means to prevent PMD, reduce economic losses, and ensure sustainability of the northeast dairy industry. The goal is to identify blood metabolites in overconditioned dry cows that could predict pre-onset PMD. Mass spectrometry has been employed to identify blood metabolites predicting preonset insulin resistance and hyperlipidemia in overweight monogastrics. Two such predictors are ceramides and fatty acylcarnitines, lipid mediators and biomarkers for the disease. Mass spectrometry will be utilized to identify whether these lipid mediators predict for pre-onset PMD. Using sixty transition cows in a commercial herd, blood will be collected at -30, -15, -7, and +4 d relative to calving, and body condition scores (BCS) will be recorded. Ceramide and fatty acylcarnitine levels during the far-off period will be correlated with body condition at calving, and insulin sensitivity and NEFA mobilization postpartum. Identifying at risk far-off dry cows, using biomarker discovery, is an innovative approach to prevent the onset of PMD. This project will be completed by following a detailed outreach plan.
Project objectives from proposal:
Objective 1: Identify prepartum blood biomarkers in overconditioned transition cows associated with reduced insulin sensitivity and elevated NEFA mobilization after calving. Employing cutting-edge mass spectrometry based technologies, plasma collected from prepartum cows during the far-off period will be screened for unique metabolite signatures that can mark dairy cows at risk of developing greater reductions in insulin action and a greater magnitude of NEFA mobilization. Focus will be placed on ceramides and fatty acylcarnitines, adiposederived lipid mediators associated with the development of insulin resistance and excessive lipolysis in overweight monogastrics. Monitoring biomarker levels prior to the onset of PMD might give dairy producers the ability to modify nutrition and management plans to maintain superior cow health through the transition from
gestation to lactation.
Objective 2: Inform and educate the dairy industry about approach, results, implications, and future direction. Approach specifics and results will be presented at the 2014 ADSA/ASAS joint annual meeting and a dairy cattle nutrition workshop for review and feedback by dairy researchers, producers, and industry representatives. In addition, a manuscript will be submitted to the Journal of Dairy Science for peer review. To address more dairy producers, an article communicating methodology, results, implications, and future direction will be submitted to DAIReXNET, the interactive cooperative extension on-line education platform.