MAIZE SILAGE IN THE DRY SEASON FOR GRAZING DAIRY COWS IN SMALL-SCALE PRODUCTION SYSTEMS IN MEXICO'S HIGHLANDS

The aim was to determine the productive and economic response to feeding maize silage (MS) at 3, 6 and 9 kg DM/cow/d, to continuous grazing cows with a high stocking rate and low herbage allowance during the dry season. Six Holstein cows were used in a repeated 3 x 3 latin square design. Cows received 2.5 kg/d of DM of commercial concentrate. Treatments consisted of 3, 6 and 9 kg of DM/cow/d of MS. There were no differences on response variables (P > 0.05), milk yields (19.0 kg/cow/d), fat and protein content (33.5 and 32.8 g/kg(-1), respectively), live weight (473.6 kg), body condition score (1.75), and total DMI (13.86 kg/cow/d). Total feeding cost/kg of milk was $0.06, $0.07 and $0.08 (USD), for treatments 3, 6 and 9 kg/DM of MS, respectively. Increasing MS to either 6 or 9 kg/cow/d did not increase milk yields compare to 3 kg/cow/d, but it does reduce profits.