The effects of forage type and level of concentrate supplementation on food intake, diet digestibility and milk production of crossbred cows (Bos taurus X Bos indicus)

An experiment was carried out to evaluate the effects of forage type and level of concentrate supplementation on forage intake, diet digestibility and milk production. Twenty-four crossbred cows (Bos taurus X Bos indicus), in early lactation, were allocated to the following six dietary treatments: native grass hay (H) or oat-vetch hay (OV), offered ad libitum, and supplemented with either 0, 2.5, or 5 kg per cow per day of wheat-middling-based concentrate. Daily dry-matter intake was higher with cows on H diets compared with those on OV diets. However, OV diets were more digestible resulting in higher daily intake of digestible DM. The daily milk yield was higher for cows on OV diets compared with H diets. Milk fat concentration was higher, but milk protein concentration was lower with H diets. The rates of rumen degradation of DM and nitrogen of OV were higher than that of H for all incubation periods; similarly the values of the rate constant of DM and nitrogen were greater for OV than for H. Daily DM intake increased when the amount of concentrate increases. The apparent DM digestibilities of the diets were higher when the diets were supplemented with concentrates. Milk yield increased when the level of concentrate given increased