Feed intake, performance and redox status in Holstein and Girolando F1 heifers presenting high body condition score during the transition period

Abstract This preliminary study aimed to compare feed intake, milk production and composition as well metabolites in blood, and redox status in Holstein and Girolando F1 (½ Holstein × ½ Gyr) heifers presenting high body condition score (BCS) during the transition period (-d15 to d21 related to calving). A completely randomized experimental design was used, testing the effect of two different genotypes with measures repeated in time (days within periods) and 12 replicates. Data about feed intake (DMI), body weight, BCS, blood metabolites, biomarkers related to redox status as well as milk production and its composition were analyzed. During the transition period, Girolando F1 heifers had higher BCS than Holstein heifers, but lower DMI. During the prepartum, Girolando F1 heifers presented higher glucose than Holstein heifers, and on day6 before calving, Girolando F1 heifers had higher creatinine, but lower NEFA than Holstein heifers. During the postpartum, Girolando F1 animals presented higher oxidation of dichlorofluorescein in the plasma compared with Holstein. Girolando F1 animals produced less milk compared with Holstein between d4 and d21. When fed the same diets on pre- and postpartum periods, Girolando F1 had higher BCS, consumed less feed and produced less milk compared with Holstein. It is worth to notice that despite differences between Holstein and Girolando F1 heifers on glucose, creatinine and NEFA during the prepartum, and on the concentration of oxidized dichlorofluorescein in plasma during the postpartum, this study shows that Girolando F1 and Holsteins heifers with high BCS during the transition period present similar physiological and metabolic issues.