Assessment of cleantech options to mitigate the environmental impact of South African dairy farming

Milk production in South Africa has increased substantially over the past ten years and is associated with various environmental impacts. These can be reduced by different means, four of which were analysed in this study: choice of breed, the use of methane emission reducing feed additives, solar power as well as variable frequency drive usage in fodder irrigation. The results showed that Holstein cows had a lower impact than Ayrshire cows per litre of milk, but that differences between farms were greater than between breeds alone. The feed additive 3-nitrooxypropanol (3NOP) led to an 18% reduction in the climate change impact category, and did not have negative effects in other categories. Using solar power for irrigation decreased the environmental impact by a larger degree than integrating a variable frequency drive to reduce the electricity demand of the water pump. All four are adequate means of reducing the environmental impact of milk