Summary of final report:
This report presents the results of the case study “Climate friendly organic milk production” carried out in Italy as part of the “On-farm participatory research” in the SOLID project (Task 1.4 of WP1). The report describes the execution and findings of the trial and the LCA study performed at the Hombre organic farm.
The main goal was to evaluate the environmental performance of two different diets administered to a dairy herd (one consisting of almost all feed ingredients produced on the farm and the other composed of both feedstuff produced on the farm and purchased raw materials) to reduce environmental impact.
The feeding trial was carried out with 136 dairy cows (Italian Friesians) between January and March 2014. An attributional and cradle-to-farm-gate LCA approach was used to estimate the carbon footprint of the diets. Furthermore, the diets were assessed for their economic sustainability.
The results of this study indicate that the cows fed with a home-grown ingredient diet had a lower milk yield compared to those fed with a standard diet. The qualitative characteristics of milk were not affected by the diets. The impact of the experimental diet) on global warming, calculated in terms of kg of CO2-eq, is higher than the control diet (1.16 kg CO2-eq compare with 1.05 kg CO2-eq).This is mainly due to a reduction of milk production in the experimental system.
The protein content of feeds crucially affects the milk yield of cows. The ingredients of the experimental diet were limited to currently home-grown feeds, their protein content was mainly derived from alfalfa hay, while the protein content in the control diet was derived from soybean meal. Therefore, it has been suggested to integrate other home-grown crops. For example, faba-beans or peas are both suitable crops for improving home-grown protein supply to low input dairy systems and could be viable alternatives to soy with lower impact on the milk yield.
With regards to the economic evaluation, the overall impact on income of the experimental diet – at current milk prices – is negative, but the financial loss from the lower milk yield can be partially recovered through the lower cost of the home-grown ration.