Impact of intensive maize silage supplementation on milksolids production, mastitis and profit

Abstract

Over four dairy seasons (2000/2001 to 2003/2004) the input of maize silage was evaluated at the Waimate West Demonstration Farm. Two systems were evaluated with Jersey cows: Control (3.8 cows/ha, no maize silage) and High stocked (HS) Maize (5 cows/ha, up to 1.5 t dry matter (DM)/cow/yr as maize silage). Both farmlets received 190 (±5) kg nitrogen (N)/ha/yr in split applications throughout the season, and calving commenced on 9 July for both herds. Only small differences between treatments in annual milksolids (MS) yield/cow were recorded. The Control herd averaged 310 kg MS/cow in 260 days compared with 316 kg MS/cow in 277 days for the HS Maize herd. The HS Maize herd produced 34% more MS/ha than the Control herd, viz. 1566 and 1172 kg/ha/yr respectively. Milksolids response to the additional DM and higher stocking rate (SR) on the HS Maize system averaged 80 g MS/kg extra DM consumed. The annual economic farm surplus (EFS) averaged over 4 years for the Control herd was $2784/ha and the HS Maize herd was $2551/ha, however greater between year variation in EFS was noted for the HS Maize system. Incorporation of maize silage into a pasture-based dairy system does increase production/ha, however the profitability of the system will be more vulnerable to MS payout and maize silage price than the traditional pasture-based system. Keywords: dairy, economic farm surplus, maize silage, pasture production