Impacto ambiental de la inclusión de saponinas en dietas fibrosas sobre la función ruminal y mitigación de emisiones de dióxido de carbono y metano entérico en bovinos

Abstract

The objective of the present investigation was to evaluate in vitro the effect of the inclusion of saponins and GISAG in fibrous diets on ruminal function, mitigation of GHG emissions, as well as ammoniacal nitrogen production; 6 bulls with ruminal cannulas were used, fed with a base diet of 50% maralfalfa grass (Pennisetum purpureum) plus 50% corn bale (Zea mays), the treatments were: T control only base diet, T2 base diet plus 3 % of saponins, T3 base diet of 3% GISAG (Saccharomyces cerevisiae) and T4 base diet plus 3% saponins and 3% GISAG, a completely randomized design of 4 treatments and 6 repetitions was handled, the variables were analyzed through an analysis of variance in the SAS PROC GLM program and for the comparison of means, the 5% Tukey test was performed, the animals were housed in individual pens and water at will, with respect to the variable in vitro digestibility of MS showed no differences between treatments (P = 0.7684) while the population of protozoa in the rumen evaluated at different hours of fermentation, showed no differences (P> 0.05), except for Entodiniomorphic protozoa at hour 24 (P = 0.0001), the decrease in vitro of this population of protozoa observed at 24 hours in T2, with respect to gas production, was less (P = 0.0111) in the T2 treatment with 37.2 mL of gas / 0.5g DM fermentable, the methane production did not show differences between the evaluated treatments (P = 0.3592), however, the CO2 production was lower (P = 0.0196 ) in T2, the volatile fatty acids did not observe differences between the treatments; however, in ammoniacal nitrogen it was higher (P> 0.05) in treatments T2, T3 and T4, with T2 being the one with the best behavior in GHG mitigation and nitrogen utilization for the productive benefit of the animal.