Abstract

In 1998 a three-year dairy farm monitoring programme was established on twelve dairy farms in the southern North Island of New Zealand where production policy had changed from a focus on high production per hectare through high stocking rates to a strategy based on high production per hectare through enhanced production per cow. Results of the third year for nine of these farms revealed a range of apparent feed intake (50,669 - 70,135 MJ ME/cow/year), milksolids production (372 - 432 kg MS/cow/year) and feed conversion efficiency (6.0 - 7.4 g MS/MJ ME intake). There was a significant positive correlation (R2= 0.57, P<0.05) between annual apparent ME intake per cow and annual milksolids production per cow, with a regression coefficient equivalent to 2.5 g MS produced per MJ ME intake, but a significant negative correlation (R2 = 0.80, P<0.01) between ME intake and feed conversion efficiency. The apparent ME intakes measured were 21% and 8% higher than theoretical requirements for the farms with higher and lower (compared to each other) milksolids yield values, respectively. This suggests that the high-performance farms may have wasted more feed. Implications for management of feed resources to optimise efficiency in high-production systems are discussed.

PV, Salles, PNP Matthews, CW Holmes, J Hodgson, and NM Shadbolt

Proceedings of the New Zealand Society of Animal Production, Volume 63, Queenstown, 96-100, 2003