Abstract

The aim of this study was to analyze feeding practices in Costa Rica’s dairy farms and their influence on greenhouse gas emissions (GHG). Methane (CH4), nitrous oxide (N2O), and income over feed cost (IOFC) were evaluated. This study was carried out at 104 dairy farms, which were distributed within a range of altitude from 1000 to 2400 meters above sea level. Using cluster analysis based on type of feed, grazing period, areas of forage and pastures; four feeding strategies were identified, which included different proportions of feed categories in daily rations. Emissions expressed as carbon dioxide equivalent per kilo of fat and protein corrected milk (CO2eq/FPCM) were higher for forage feeding strategies and lower for farms found in higher altitudes. Concentrate feed accounted for the higher cost in all feeding strategies, and represented more than 50% in the intensive concentrate based production system, whereas the costs of fertilizers were higher in pasture based feeding strategies. Income from milk sales was higher for the concentrate based feeding strategy. However, IOFC was the same for all feeding strategies in spite of the large differences in daily milk production. Feeding strategies influenced GHG emissions and feeding costs. Feeding strategies associated with lower GHG emissions within the farm were more dependent from external inputs.

Keywords: tropical dairy farms, income over feed cost, feeding cost, GHG emissions, methane, nitrous oxide.