Evaluación productiva de sistemas pastoriles de producción de leche en estrategias de bajo costo y alta productividad para la estación de invierno

The reality faced by Uruguayan dairy producers is challenging given the global context, marked by fluctuations in milk prices and production inputs. This scenario presents both challenges and unique opportunities for each system, underscoring the need to explore new frontiers in managing livestock and feeding strategies to enhance the competitiveness and sustainability of this sector. For this reason, the current experiment, framed within a project of the Red Tecnológica de la Cadena Láctea (RTCL), aimed to evaluate two contrasting productions assessed at the farm system level (farmlet). One was a low-cost (LC) strategy aimed at greater operational simplicity with low production costs, with a stocking rate of 1.8 milking cows per hectare of platform, and the other, called high productivity (HP), aimed to achieve high milk production per hectare with a stocking rate of 3.0 milking cows per hectare of platform. Fieldwork covered the months between June and August 2023 and was carried out at the Centro Regional Sur, in Canelones, Uruguay. The variables examined for both systems included forage production and harvest per hectare, forage stock, availability at pre- and post-grazing times, confinement times, grazing opportunities, feeding structure, and individual and per hectare milk production. Pasture measurements were taken weekly using the C-Dax and RPM tools, with results analyzed utilizing a Completely Randomized Block Design. Confinement times, feeding, and milk production variables were analyzed using a Completely Random Design. The results indicated that during the winter season, no significant differences were observed between treatments regarding forage production and harvest per hectare or forage stock, which can be explained by grazing and supplementation management.  However, distinctions emerged in feeding structure, confinement times, and grazing opportunities, with the AP system exhibiting a greater reliance on diet supplements, lengthier confinement periods, and fewer grazing opportunities. This aligns directly with the higher productivity per hectare achieved by this system. Furthermore, differences were also found in individual milk productivity, where the BC system presented higher production, which was unexpected given the design of each system. Despite these differences, both systems achieved high forage production and harvest, with high milk productivity per hectare, making them promising strategies for Uruguayan dairy production, not only from a production standpoint but also by incorporating management and feeding strategies that require less operational demand and pressure on human resources.