Abstract
This study was conducted to investigate the effects of 10 weeks supplementation of Quebracho tannins (QT; 0 [control], 100 [QT(100)] or 200 g/[cow·d] [QT(200)]) to 30 multiparous postpartum buffalo cows (10 cows per group) on milk yield and composition, blood metabolites and reproductive performance. Supplementation of QT(100) had no significant effect on milk yield, whereas QT(200) decreased (P < 0.05) this trait. Compared with the control group, both QT levels decreased (P < 0.05) fat-corrected milk (FCM) yield, but no significant effects were found on percentages of milk fat and protein. Contrariwise, yields of milk fat, lactose and milk protein were decreased (P < 0.05) when QT(200) was supplemented. The solids nonfat (SNF) percentage and yield were decreased (P < 0.05) with QT(100) supplementation. Moreover, QT tended to numerically reduce total number of ovarian follicles, number of small follicles, peripheral progesterone concentration and conception rate. Supplementation of QT(200) numerically increased number of large follicles, mean diameter of large follicle, number and diameters of corpora lutea. The inclusion of QT(200) shortened days open (DO) and decreased number of services per conception. Contrariwise, QT did not show significant effects on serum total protein, albumin, globulin, glucose, cholesterol and triglycerides concentrations. Supplementation of QT(100) caused an increase (P < 0.05) of serum urea compared with that in control and QT200 groups. Generally, QT decreased (P < 0.05) serum creatinine concentration. Therefore, the supplementation of a commercial QT to early lactating Egyptian buffalo cows displayed negative consequences on their productive and reproductive performances.