SILAGENS DE MILHO PRODUZIDAS E FERTILIZADAS COM BIOFERTILIZANTE SUÍNO INFLUENCIA A CINÉTICA DE PRODUÇÃO DE GASES RUMINAIS?

Abstract

The objective of this study was to evaluate the ruminal degradability of corn silages produced with corn fertilized with swine biofertilizer in combination and / or substitution to mineral fertilization using the in vitro gas production kinetics technique. The study was carried out in completely randomized design in factorial scheme 22, in which the factors are: the type of fertilization in the moment of planting (chemical and porcine biofertilizer) and the type of coverage (chemical and porcine biofertilizer), with four replications. The corn plants were harvest, chop, ensile in experimental silos and stored for 21 days, when they are open. Then samples were collected and dried in forced ventilation stove. After the drying and milling of samples, an aliquot of 0.5 g was incubated in buffered ruminal fluid for 48 hours, with internal pressure bottles measured every 15 minutes. Subsequently, they were adjusted to non-linear functions (Brody, Bertalanffy, France, Gompertz, Modified Logistics and Bicompartmental Logistics). There were used the Akaike (AIC) and Bayesian (BIC) information criterion for selecting the function with the best quality of adjustment of silages gas production data. After the selection, a model identity test was carried out with the aim of selecting the model that has a greater variation of data (simple model: without treatment effects; reduced models: only considers the effects of the type of fertilization, at planting or coverage moment; and complete model: consider a combination of two levels (planting and coverage moment). After defining the appropriate model, it was carried out the individually adjustment, followed by a BootStrap resampling and the data obtained was compared with a BootStrap test (P <0.01). A non-linear function Bertalanffy appears to have a better adjustment quality for the kinetics of ruminal gas production, with lower AIC and BIC values. The complete model shows significant differences compared with the reduced models (planting and coverage) and simple (P <0.01). The silage fertilized with porcine biofertilizer in planting and covering (BIOBIO) presented the best parameters of gas production kinetics.