DEGRADABILITY AND RUMINAL FERMENTATION KINETICS OF FOUR MAIZE HYBRID SILAGES EVALUATED UTILIZING THE SEMI-AUTOMATED In vitro GAS PRODUCTION TECHNIQUE

Dry matter digestibility and fermentation kinetics of four maize hybrid silages with different vitreouness on grain (SHS 4040, QPM 129, AG 1051 and BRS 3060) were evaluated utilizing the semi-automated in vitro gas production technique. The chosen statistical design was the randomized blocks, with bovine inoculum as blocks, the hybrids as plots and time of incubation as subplots. The means were compared by SNK test (p < 0.05). When comparing hybrids in different fermentation periods, the BRS 3060 was statistically superior to the AG 1051 for cumulative gas production after 24 hours of incubation. The dry matter degradability (DMD) values after 96 hours of incubation were: 57.7% for SHS 4040, 61.9% for QPM 129, 59.7% for AG 1051 and 65.9% for BRS 3060. The SHS 4040 and AG 1051 presented the lower DMD. The maximum gas production potentials ranged from 213 mL/g of dry matter for AG 1051 up to 233 mL/g of dry matter for BRS 3060. The hybrid BRS 3060 stood out against other materials due to its highest accumulated gas production and highest dry matter digestibility. The AG 1051 stood out against other silages due to its highest gas production rates and lowest colonization time, influenced by dent texture of the grains