Effects of different concentrate supplementation levels on growth performance, blood markers, and economic return of yaks grazing in the warm season

We investigated the effects of different levels of concentrate supplementation on the growth performance, blood markers, and economic return of yaks grazing in the warm season on the Qinghai-Tibet Plateau, aiming to provide a theoretical basis to guide the supplementary feeding of yaks. Forty-eight male yaks with good body condition and similar weight (123.96 ± 7.43 kg) were randomly divided into four groups (n = 12). The control group only grazed, while the three supplement groups received 0.5, 1.5, and 2.5 kg·d⁻¹ of concentrate. The pre-test period was 10 days, and the formal experiment lasted 60 days. The supplementary feeding had a significant effect on the yaks’ average daily gain (ADG) (P < 0.05). The group receiving 2.5 kg·d ⁻¹ of supplement had the highest ADG (286.42% higher than the control group). Compared to the control group, the 1.5 and 2.5 kg·d⁻¹ supplement groups had significantly higher glucose, total protein, and aspartate aminotransferase (P < 0.05) levels; however, urea nitrogen levels were significantly reduced in the 2.5 kg·d ⁻¹ supplement group (P < 0.05). 3) The supplement groups produced a greater economic return than did the control group, with that of the 2.5 kg·d ⁻¹ supplement group being the best. In conclusion, supplementary feeding increased the daily weight gain and economic return of yaks grazing in the warm season, with 2.5 kg of concentrate appearing to be the most appropriate amount to use in supplementary feeding.