The current experiment will assess the biological efficiency of six grass-based systems of milk production in terms of overall animal productivity and pasture growth, utilisation and quality. The experiment examines three alternative autumn spring feed budgets x 2 grazing intensities, resulting in 6 treatment groups of 20 cows per group. Animals will be randomly assigned to one of three alternative autumn spring pasture-based systems differing in overall peak feed supply (Low -1,000 kg DM/ha), Medium- 1,200 kg DM/ha and High – 1,400 kg DM/ha) established based on alternate autumn rotation lengths. To each feed supply system, 2 grazing intensities (lax – 4.5 cm post grazing residual and severe -3.5cm grazing residual) will be applied for the duration of the autumn and spring.
- To quantify the impact of alternate pasture-based production systems differing in autumn & spring feed budget strategies in terms of grazing season length, supplementary feed requirements and animal performance within high stocking rate grazing systems.
- To establish the immediate and carryover sward effects of alternative autumn spring grazing strategies and the interaction between grass supply management and grazing intensity within spring calving grazing systems