EFFECT OF AGE AND CUTTING HEIGHT OF HYBRIDS OF Urochloa sp. ABOUT In vitro GAS PRODUCTION

Abstract

Background. The production of ruminants in the tropics is based on the grazing of grasses, which present variations in their nutrient content depending on the intensity and frequency of cutting. Objective. To determine the effect of cutting intensity and regrowth age of the morphological composition of three hybrids of the genus Urochloa sp on gas production and in vitro gas production kinetics. Methodology. The samples were formed by the interaction of three morphological-hybrids (Cobra, Cayman and Mulato II-leaf and stem), two cutting intensities (10 and 15 cm) and 5 regrowth ages (7, 21, 35, 49 and 63 d). Partial and accumulated gas production, maximum volume (V), gas production rate (S) and Lag time (λ) were determined for the samples. The statistical design was a 6 x 2 x 5 factorial arrangement within a completely randomized design. Results. The leaves and stems of Cobra and Cayman showed the highest partial and cumulative in vitro gas production (p<0.05). The evaluated variables were not affected by the cutting intensity and the behavior in the in vitro tests was greater at 21 and 35 days of regrowth of the pastures. Implications. The cut intensity variable did not modify the mean values of the variables evaluated in this research work, while age negatively affects it. Conclusions. The leaves and stems of Cobra and Cayman grasses showed the highest partial and cumulative in vitro gas production.

Keywords

• urochloa
• híbrido
• producción gas
• forrajes