Effect of supplementation of β-carotene on nutrient intake, digestibility, milk yield and composition lactating crossbred cows

Abstract

This study investigated the effect of supplementation of β-carotene on nutrient intake, digestibility, milk yield and composition lactating crossbred cows. Twenty four crossbred (Holstein × Sahiwal) cows with a close date of calving were divided into two homogeneous groups based on parity (4.62 ± 0.46) and milk production level within the current lactation (8.57 ± 0.08 kg/day of mature equivalent milk). During the lactation period, the cows of the BETA-group were fed a diet supplemented with 500 mg/cow/d of β-carotene. Compared to CONT-group (control), BETA-group (β-carotene supplementation diet) failed to increase body weight, dry matter intake and digestibility of crude protein, crude fiber and nitrogen free-extract except ether extract and intake of total digestible nutrients which increased (p < 0.01) in BETA-group. Overall daily milk yield, total milk yield, 3.5% fat-corrected milk, energy-corrected milk, fat yield, protein yield, lactose yield, solid not fat yield and total solids yield did not differ between two groups. No differences were observed in milk composition as fat % (3.36 ± 0.03), protein % (3.08 ± 0.04), lactose % (4.25 ± 0.03), solid not fat % (7.48 ± 0.03) and total solids % (10.80 ± 0.05) between CONT and BETA-groups. Furthermore the somatic cell count was also not different the groups. The results of the present study demonstrated that supplementation of β-carotene has no significant benefits on productive parameters of lactating crossbred cows.