Balance forrajero, de energía y nitrógeno en pastizales arborizados con Algarrobo (Prosopis juliflora (S.W.) DC.) bajo pastoreo de vacas lecheras

The purpose of this study was to evaluate the effect of Algarroba (Prosopis juliflora (S.W.) DC.) trees on nitrogenenergy forage contents, on Ecuadorian dairy farms grasslands. The study was made at ESPAM bovine facility, 15meters above sea level, in Manabí, 00º49’23’’, south latitude, and 80º11’01” west longitude, with 962.4 mm annual precipitatio n, between September 2011 and December 2014. The stocking rate was 1.09 LU/ha. There were 1-4 algarroba trees/ha by 2011, and 8-35 trees/ha, in 2014. Evaluations of forage nitrogen and energy were based on the effects of arborization. As a result, 52 t of DM were estimated in 2014, in comparison to the 21 t of 2011. Nitrogen was higher with increased arborization between 2011 (60.9 kg/ha), with greater nutrient intake from external sources, and 2014 (39.3 kg/ha), with less input of supplements and mineral fertilizers, and greater N2 contribution by arborization. Energy was higher in 2014, with an increase in algarroba population/ha. The increase of trees/ha favored forage yields, with improved N2 and energy efficiency, which was linked to the benefits acquired by the grassland, the contribution of livestock to the ecosystem, and the reduction in feeds and fertilizers