Productivity, Profitability and Nitrogen Utilisation Efficiency of Two Pasture-Based Milk Production Systems Differing in the Milking Frequency and Feeding Level

The aim of this study was to model the productivity, profitability and nitrogen (N) utilisation efficiency (NUE) two spring-calving pasture-based milk production systems differing in milking frequency intensification levels New Zealand. For purpose, physical performance data from a low-intensity system where cows were milked once per day (OAD-LI) high-intensity twice (TAD-HI) employed. OAD-LI once-daily with stocking rate (SR) 2.1 cows/ha fed diets low supplementation (304 kg pasture silage/cow) applications 134 N fertiliser/ha TAD-HI twice-daily SR 2.8 higher (429 silage 1695 concentrate/cow) 87 fertiliser/ha. Moorepark Dairy System Model used evaluate production, economic balance on an annual basis. Despite feed costs as more utilised, hectare 16% because yield cow (milking frequency) when compared OAD-LI. At level, NUE (30% vs. 27%) reflecting better balanced diet for energy crude protein yields result frequency. farm scale (38% 26%) due losses associated imported being excluded captured milk. These results suggest that frequency, use application fertiliser management tools grazing dairy affect balance. Further studies are required find optimal rates combination supplementary maximize OAD TAD but minimize losses.