Graduate Research and Discovery Symposium (GRADS)


T.C. Jenkins

Document Type



Animal and Veterinary Science

Publication Date

Spring 2013


The objective was to design a system that could detect gas concentrations continuously in ruminal continuous cultures to better assess changes in methane (CH4) occurring before and after feeding. The custom-built system used CH4 and CO2 infrared sensors, and an O2 infrared sensor. Thirty g of Tifton 85 bermudagrass harvested at 35 d of maturity was fed daily in two equal amounts at 0800 and 1600 h for three 7 d periods. For statistical analysis, hourly recordings were used between 0800 and 1600 h on days 5, 6 and 7. Data were analyzed by the Fit Model Procedure in JMP (SAS Institute) with time, day, and their interaction as main effects and period as random effect. Methane production increased (P<0.01) between 0800 and 1600 h (12.1, 12.6, 17.0, 21.9, 23.6, 26.4, 26.9, 27.1 and 28.1 mmol) when averaged across d 5-7. A decrease (P<0.01) in methane production on d 7 (26.1, 23.7, 15.4 mmol/d for d 5-7) is thought to result from repeated opening of the culture vessel to obtain samples. The novel gas analysis system developed for continuous cultures in this study successfully measured changes in CH4 concentration before and after feeding that were comparable to previously reported values.