BLACK OAT (Avena strigosa) SILAGE FOR SMALL-SCALE DAIRY SYSTEMS IN THE HIGHLANDS OF CENTRAL MEXICO

Abstract

Black oat (Avena strigosa cv. Saia) silage (BOS) as an alternative forage for the dry season in small-scale dairy systems was evaluated against maize silage (MSL) at 6.0 kg DM/cow/day. Treatments were evaluated through on farm participatory livestock research: T1=100 BOS, T2=66:34 BOS:MSL, T3=34:66 BOS:MSL, and T4=100 MSL fed to milking dairy cows that also received 4.5 kg DM/cow/day of a commercial compound dairy concentrate and 2.2 kg DM/cow/day of cut-and-carry pasture. Eight Holstein cows were allotted to a replicated 4X4 Latin Square design, with 14 day experimental periods. Daily milk yields and milk composition were measured during the last four days, and live weight and body condition score recorded on the last day of each period. Feeding costs were determined by partial budget analysis. There were no differences in milk yield (15.9±0.26 kg/cow/day), or milk composition with mean values for milkfat of 38.8±0.86 g/kg, milk protein 32.2±0.38 g/kg, and lactose 46.3±0.22 g/kg. There were also no differences in milk urea nitrogen (MUN) with a mean of 11.8±0.83 mg/dl, live weight 385.6±1.67 kg, or body condition score with a mean of 2.6±0.01. Feeding costs per kg milk were 33% higher in T1 and T2 than T4, with intermediate feeding costs in T3 (T1=0.88, T2= 0.85, T3= 0.74, T4= 0.66 R$/kg). Profit margins and income/feeding costs were all positive. Black oat silage may be an alternative forage in small-scale dairy systems in the dry season when maize silage cannot be cultivated or fails due to climate concerns.