Effect of a Highly Fortified Vitamin-Mineral Supplement in High- and Low-Concentrate Rations for Dairy Cows

Open Access
Publisher Website
Google Scholar
Abstract
Sixteen Holstein cows were used in a 112-day feeding trial to study the effect of feeding a vitamin-mineral supplement with 15:85 and 60:40 hay concentrate rations on milk yield and composition, and digestibility of the rations. The cows fed the supplemented low-concentrate (l.c.) ration maintained their level of fat-corrected milk (FCM) production significantly (P<.05) better than those receiving the non-supplemented l.c. ration; however, supplementation showed no advantage with the high-concentrate (h.c.) ration. Neither hay-concentrate ratio nor supplementation, per se, affected persistency of FCM production. The observed total-digestible-nutrient (TDN) coefficients of the h.c. rations were approximately the same as those of the l.c. rations. The average TDN intake from the h.c. rations was 16.7% less than that from the l.c. rations. The h.c. ration depressed milk fat percentage initially but not after the first 4 weeks of the trial.