75 (2)s 95-105

Title: 
Typical metabolic changes in high producing dairy cows early postpartum and their consequences on oocyte and embryo quality
Author(s): 
J.L.M.R. LEROY, T. VANHOLDER, G. OPSOMER, A. VAN SOOM, P.E.J. BOLS, A. DE KRUIF
Abstract: 

The negative energy balance (NEB) is characterized by typical biochemical changes such as high non-esterified fatty acid (NEFA), high β-hydroxybutyrate (BHB) and low glucose concentrations. The concentrations of these metabolites were extensively analyzed in the follicular fluid of high yielding dairy cows during NEB and were imitated in in vitro maturation models to investigate their effects on oocyte quality. The studies reviewed in this paper showed that the typical metabolic changes that occur during NEB are well reflected in the follicular fluid (FF) of the dominant follicle. However, the oocyte seems to be relatively isolated from excessively high NEFA or excessively low glucose concentrations in the blood. Nevertheless, the in vitro maturation models revealed that such metabolic changes in the FF associated with a NEB (high NEFA and low glucose concentrations) are indeed toxic for the oocyte, resulting in hampered oocyte maturation, increased apoptosis and necrosis in the cumulus cells, and jeopardized developmental competence of the resulting embryos. Only in moderately hypoglycemic maturation conditions did BHB have an additive toxic effect. These in vitro maturation models, based on in vivo observations and reviewed in this paper, suggest that a period of NEB may hamper the fertility of high yielding dairy cows through increased NEFA and decreased glucose concentrations in the FF, directly affecting oocyte quality. Finally, it was also demonstrated in our lab that the embryo quality of lactating high producing dairy cows is inferior compared to that of non-lactating dairy heifers or beef cows.

Full text: 
pp 95-105
Review(s)