Estrategias de intensificación en sistemas de producción de leche y sus impactos ambientales

Doctoral thesis abstract

Resumo

Intensification of milk production systems, or the process of increasing total milk productivity (kg) per cow or per unit of land area, can be achieved through various strategies, such as increasing animal load, consumption of concentrates and forage. However, it is debated whether intensification is associated with greater economic and / or environmental efficiency. In Uruguay, increased milk production from pasture-based systems has implied greater use of concentrates and inputs, leading to greater environmental impact. In general, these impacts are expressed per unit of product, which does not reflect the local impact per unit of land. The objective of the work was to analyze the intensification strategies of the milk production systems in Uruguay and explore the productive, economic and environmental impacts that are generated from a series of indicators such as Greenhouse Gases (GHG), consumption of fossil energy, ecotoxicity and eutrophication potential. Although the increase in the use of concentrates in the diets was associated with higher milk productivity and an increase in the gross economic product and total input costs, these were consistently negatively associated with energy efficiency expressed in MJ.l-1 . The dairy systems with higher production had lower GHG but higher ecotoxicity per kg of milk than the systems with lower milk production. The results suggest that increasing milk productivity did not reduce environmental impacts per kg and increased impacts per ha. To determine the environmental impacts that are generated from the intensification of dairy production systems, it is more relevant to analyze the feeding strategy (greater proportion of pastures or concentrate) and the amount of agrochemicals, than the variables associated with productivity.