Assessment of food-feed competition for producing milk in cow dairy farms

CONTEXT: The demand for animal products is increasing worldwide, despite concerns about their negative impact on the environment, animal welfare, and human health. It is crucial to understand the role of animal husbandry and assess its contribution to the food supply chain. OBJECTIVE: This study aimed to analyse the efficiency of dairy farms in producing food by evaluating the competition between animal and human in terms of feed - food soil utilization and net nutrients. METHODS: The study used three approaches: Land Use Ratio (LUR), Human-edible feed conversion net ratio (heFCRn) for energy and protein and Global warming potential (GWP) evaluation. A group of 10 dairy cattle farms in Northern Italy was selected, based on herd size and farm management practices, in order to provide a representative sample of the intensive dairy systems in this region. RESULTS AND CONCLUSION: The three indices (heFCRn energy, heFCRn protein, LUR) were correlated with each other and with Global Warming Potential (GWP) per kg of Fat Protein Corrected Milk (FPCM). The heFCRn protein index was found to be particularly related to GWP (R2 = 0.88). The LUR, applied at the farm level, identified high variability (1.07 ± 0.8) among individual farms with herd size (R2 = 0.82), milk production (R2 = 0.86), land availability (R2 = 0.77) and by-products use (R2 = 0.49) inversely correlating with LUR. The study suggests increasing milk production and using by-products in animal rations as important strategies for reducing food-feed competition in terms of energy and protein supply. Further studies are needed to evaluate amino acid profiles in plant-based and animal-based products. SIGNIFICANCE: The novelty of this study is to consider, at the same time, different indices associated to sustainability of the farm process along with GWP of milk production, and the application of the LUR at the farm level. The high variability of the results among farms suggests that, from a scientific point of view, is not possible draw simply conclusions about food-feed competition but this evaluation could give important indication to identify possible strategies, which can be implemented in practice.