EFFECT OF THE LEVEL OF FEEDING ON IN VITRO METHANE GAS PRODUCTION

Abstract

Objective: To evaluate the effect of four levels of simulated in vitro feeding on the production of in vitro methane. 

Design/methodology/approach: The simulated levels of feeding in vitro were: 5.7 kg DM, 11.9 kg DM, 19.5 kg DM and 21.8 kg DS since these levels of feeding can be found in vivo in different livestock farms in the world. The technique of in vitro gas production was used to incubate samples of native grass dominated by Penisetum clandestinum (80%) and weeds (20%) in four levels; DM0.57, DM1.19, DM1.95, DM2.18 at 12, 24, 48 and 72 h.

Results: Significant differences (p<0.05) were found between the different levels of DM at 12 hours, with DM0.57 and DM1.19 being different from DM1.95, DM2.18. At 24 h DM0.57 presented the lowest concentration and was significantly different (P<0.05) of the other levels of DM. At 48 and 72 h, DM1.19 was significantly different (P<0.05) than the rest of the levels studied since it presented the lowest concentration of CH₄, while DM0.57 at 72 h presented the highest concentration of CH₄.

Study limitations/implications: The results of this study were obtained from an in vitro study, therefore, they are not directly applicable to enteric emissions in vivo; however, they represent an approximation to how much metabolizable energy can be lost in the form of methane.

Findings/conclusions: A linear effect was observed from the four levels of feeding simulated in vitro over the accumulated production of methane at 12 h post-incubation. The levels DM0.57 and DM1.19 presented the lowest methane production at 24 and 48 h, respectively.