Cinética da fermentação e taxas de degradação de gramíneas do gênero cynodon

Abstract

The in vitro gas production technique is recognized as one of the best to describe the food fermentation kinetics. The gas production is directly proportional to microbial fermentation of food. This work aimed evaluating the fermentation kinetics and degradation rates of grasses of the Cynodon genus estimated by the in vitro technique of semiautomatic gas production. The experiment was conducted at UNIMONTES, Janaúba-MG. The fodder plants were Coastcross, Tifton 85 and Tifton 68. Pressure readings were taken at times: 0, 2, 4, 6, 8, 10, 12, 15, 19, 24, 30, 36, 48, 72 and 96 h. The dry matter degradability (DMD) was obtained for the percentage of dry matter (DM) remaining after 0, 6, 12, 24, 48 and 96 hours of fermentation. It was established a relationship between pressure and volume and the regression equation was: Y = 0,1816 + 5,0998X. The total gas prodution of Tifton 85 grassy was higher than the other grasses. Grasses obtained their maximum gas production at 72 hs. The highest rates of fermentation occurred at initial time of fermentation and it was decreasing with advancing time. Significant effect was found for grasses in the fractions: soluble, insoluble potentially degradable, insoluble, potential and effective degradability. Tifton 85 and Tifton 68 grasses showed higher values for these variables in relation to Coastcross grassy. The research demonstrated the procedure to obtain the equation from volume and pressure, which allowed the installation of in vitro technique of semiautomatic gas production in the Laboratory of Food Science of UNIMONTES. It was observed a higher gas production during in vitro incubation of dry matter for grass Tifton 85.