Evaluating pasture-based dairy cow wintering systems across soil and climatic conditions in southern New Zealand: implications for nutrition, welfare and environmental risk

Abstract

Autumn-saved pasture offers a potentially attractive alternative for wintering livestock in the South Island, although variability in feed accumulation and uncertainty over suitability on poorly drained or structurally vulnerable soils constrain adoption. We evaluated pasture-based wintering using six case-study farms across Canterbury, Otago and Southland selected to represent a range of soil, landscape and rainfall conditions. Kale and fodder beet paddocks within a wintering system were also assessed on two farms. System performance was evaluated using proxy indicators including assessments of ground cover (drone-derived), soil condition, cow cleanliness, body condition score and diet adequacy. Overall, body condition score (BCS) outcomes from the pasture wintering case studies indicated adequate nutrition
despite variation in estimated ME supply. Where soils were suitable, pasture systems delivered improved cow cleanliness and reduced environmental risk compared with forage crops that were monitored on two of the farms. Successful outcomes were associated with permeable, structurally resilient soils and lower grazing pressures (≥15 m² cow-¹ day-¹) than typically applied to winter forage cropping systems.