2026-06-09T09:01:29+02:00 https://library.wur.nl/oai

oai:library.wur.nl:wurpubs/386990 2026-03-31

urn:nbn:nl:ui:32-386990 2026-03-31 urn:nbn:nl:ui:32-386990/mods Influence of management and genetic merit for milk yield on the oxidative status of plasma in heifers Wullepit N. aut Raes B. aut Beerda B. 156039745 0000-0002-6776-1969 0000000363144995 aut Veerkamp R.F. 314602232 0000-0002-5240-6534 0000000396451684 aut Fremaut D. aut de Smet S. aut text info:eu-repo/semantics/article 2009 10.1016/j.livsci.2008.11.013 2-s2.0-67349266212 000267012300024 en This study was part of a larger study that addressed whether milk production levels affect health risks in dairy cows as influenced by genetic merit for milk yield and management factors. Plasma samples were collected from 80 Holstein Friesian heifers at 2 weeks pre-partum and at 4 and 8 weeks post-partum in a 2 × 2 × 2 factorial arrangement design with the factors breeding value for milk production (high or low), milking frequency (2 or 3 times a day) and feed energy density (high or low). The following parameters indicative of the oxidative status were measured in plasma: ferric reducing ability of plasma (FRAP), a-tocopherol level, glutathione peroxidase activity (GSH-Px), superoxide dismutase activity (SOD), thiobarbituric acid reactive substances (TBARS) concentration and paraoxonase activity (PON). There was a significant effect of time for FRAP, a-tocopherol, GSH-Px and SOD, indicating changes in the plasma oxidative status around parturition. A high merit for milk yield, three-times-daily milking and especially feeding the high energy feed all stimulated milk production level. However, the influence on oxidative status parameters was minimal. Only the FRAP value was significantly lower in the high compared to the low energy group. Cows seem to undergo some oxidative stress around parturition, which can make them more susceptible to disorders. However, there were no clear indications that breeding value, milk frequency or feed energy level jeopardizes heifers in a way oxidative stress became critical WIAS Research Adaptation Physiology alpha-tocopherol antioxidant status beta-carotene early lactation energy-balance health metabolic status stress transition dairy-cows vitamin-e WIAS Onderzoek Adaptatiefysiologie Livestock Science 123 2-3 276 282 18711413 urn:nbn:nl:ui:32-386990/obj 2026-03-31 http://purl.org/eprint/accessRights/RestrictedAccess