Future dairy systems: Improved efficiency and environmental sustainability: A dissertation submitted in partial fulfillment of the requirement for the Degree of B.Agr.Sci (Hons) at Lincoln University

Abstract

Historically production increases have been a result of increased stocking rate and nitrogen fertiliser use. However, the current dairy system has an effect on water quality and does not take maximum advantage of the genetic potential of dairy livestock. The future dairy system in Canterbury must become more efficient and environmentally sustainable. Two possible future systems - a High Stocking rate Efficient (HSE) system and a Low Stocking rate Efficient (LSE) system were compared at the farmlet scale. The HSE treatment improved efficiency of production on a per hectare basis. The HSE treatment had 34% higher milk production, 8% higher pasture production, and 0.07 MJ M/kg DM higher pasture quality per hectare than the LSE treatment. Conversely, the LSE treatment improved efficiency of milk production per cow. The LSE treatment had 3.6% higher milk production per cow. Environmental impact was 2.6 times greater in the HSE treatment than the LSE treatment due to a higher nitrate loading level. This was directly related to nitrogen fertiliser application rate and stocking rate. Local and regional regulations will have a marked effect on the direction of the Canterbury dairy industry in the near future. Increasingly stringent environmental regulations will result in the development of dairy systems similar to the LSE treatment. On the other hand, a situation where milk production becomes most important, the dairy industry will become similar to the HSE treatment.