Comportamiento de la respuesta animal según producción y calidad del pastizal y estimación de la emisión de metano entérico de vacas lecheras en pastoreo

Abstract

The objective of the work was to evaluate the animal response and enteric methane emission in relation to production, structure and quality of the pasture in the experimental farm of Irquis, from the University of Cuenca, Victoria del Portete parish, Cuenca canton, in Azuay at 2663 mas at 713890 E and 9659302 N, in cold temperate climate and temperature between 8 and 14 ° C, relative humidity of 80% and rainfall of 639 mm. The research was carried out with dairy cows, in 16 weeks, between December 2018 and April 2019. The parameters evaluated were: botanical composition, pastures yield, height and structure of the pasture and chemical composition. Three types of grassland were used: Kikuyo (K), Ryegrass (R) and the Kikuyo-Ryegrass-Clover association (M). Milk production between pastures by records and methane emission was compared with equations. Yields in kgMS / ha were obtained in Ryegrass: 5300; in Kikuyo of 3590 and in the association of 3610 without differences between pastures and utilization, it was 64.56% in Ryegrass; 57.14% in Kikuyo and 61.58% in the association. Significant differences (P 0.05) were found in favor of Kikuyo, which surpassed Ryegrass due to milk production, and this indicator was similar between Kikuyo and the mixture, and this did not differ from Ryegrass either. Methane emission, without differences between pastures, yielded values of 39.41 l of methane / kg of milk in Ryegrass; 38.54 l of CH4/kg of milk in Kikuyo and 37.77 l / kg of milk in association. Despite the no differences between pastures due to yields, differences were found in the milk produced and not reported in methane, due to the differential effect of the components of structural and chemical quality.