Oat and ryegrass silage for small-scale dairy systems in the highlands of central Mexico.

Abstract

This study investigated the effects of the inclusion of oat-ryegrass silage (ORGS) in combination with maize silage (MSLG) in four treatments: T1 = 100% ORGS, T2 = 67% ORGS/33% MSLG, T3 = 67% ORGS/33% MSLG, and T4 = 100% MSLG to milking cows on continuous grazing with 4.7kg DM of commercial dairy concentrate 18% CP. Daily milk yield and composition, live weight, body condition score, and chemical composition of feeds were recorded during the last 4days of the experimental periods. Feeding costs were calculated by partial budgets. Eight Holstein lactating cows were used in a replicated 4 × 4 Latin square, with 14-day periods. There were no statistical differences (P > 0.05) for milk yield (mean 15.5 ± 5.0kg/day/cow) or composition (mean milk fat 34.6 ± 4.4g/kg, protein 32.4 ± 3.1g/kg, lactose 46.9 ± 1.6g/kg), milk urea nitrogen (11.3 ± 2.1mg/dl), live weight (434 ± 38kg), or body condition score (2.4 ± 0.15). The silage cost of ORGS was 2.5 times higher than MSLG, so the feeding cost in T1 was 26% higher per kilogram of milk than for T4, with T2 and T3 as intermediates. ORGS can be a substitute to maize silage in the proportions studied, although feeding costs were higher.