Methane Production of Different Forages in In vitro Ruminal Fermentation

Abstract

An in vitro rumen batch culture study was completed to compare effects of common grasses, leguminous shrubs and non-leguminous shrubs used for livestock grazing in Australia and Ghana on CH4 production and fermentation characteristics. Grass species included Andropodon gayanus, Brachiaria ruziziensis and Pennisetum purpureum. Leguminous shrub species included Cajanus cajan, Cratylia argentea, Gliricidia sepium, Leucaena leucocephala and Stylosanthes guianensis and non-leguminous shrub species included Annona senegalensis, Moringa oleifera, Securinega virosa and Vitellaria paradoxa. Leaves were harvested, dried at 55°C and ground through a 1 mm screen. Serum bottles containing 500 mg of forage, modified McDougall’s buffer and rumen fluid were incubated under anaerobic conditions at 39°C for 24 h. Samples of each forage type were removed after 0, 2, 6, 12 and 24 h of incubation for determination of cumulative gas production. Methane production, ammonia concentration and proportions of VFA were measured at 24 h. Concentration of aNDF (g/kg DM) ranged from 671 to 713 (grasses), 377 to 590 (leguminous shrubs) and 288 to 517 (non-leguminous shrubs). After 24 h of in vitro incubation, cumulative gas, CH4 production, ammonia concentration, proportion of propionate in VFA and IVDMD differed (p<0.05) within each forage type. B. ruziziensis and G. sepium produced the highest cumulative gas, IVDMD, total VFA, proportion of propionate in VFA and the lowest A:P ratios within their forage types. Consequently, these two species produced moderate CH4 emissions without compromising digestion. Grazing of these two species may be a strategy to reduce CH4 emissions however further assessment in in vivo trials and at different stages of maturity is recommended.

<b><i>In vitro</i> degradation and gas production of glycerin generated in the biodiesel production chain

“…The feed ingredients were dried at 55ºC for 24h and then ground to pass a 1 mm screen and incubate in vitro (Meale et al, 2012). The entire incubation procedure was repeated twice (i.e., two incubation runs x three replicates per treatment, resulting in a total of six replicate vials per treatment).…”

The biochemical and microbiological characteristics of rumen fluid from cattle co-grazed with and without camels as compared to that from the foregut of camels

“…The relatively high IVDMD, despite the high NDF and ADF contents of Mitchell grass, implies that co-grazing camels with cattle supported a more effective microbial population in camels. Similar values of the highest cumulative gas production, IVDMD, and total VFA production were shown when in vitro rumen batch culture was completed for Brachiaria ruziziensis grass and leguminous shrub species of Gliricidia sepium that are commonly used for livestock grazing in parts of Australia and Ghana (Meale et al 2012). Meanwhile, as the subject matter by Meale et al (2012) was the evaluation of feed, it does not agree well with this present co-grazing experiment as the focus was to investigate the characteristics of FF inoculants in fermentation of feed samples.…”

“…Similar values of the highest cumulative gas production, IVDMD, and total VFA production were shown when in vitro rumen batch culture was completed for Brachiaria ruziziensis grass and leguminous shrub species of Gliricidia sepium that are commonly used for livestock grazing in parts of Australia and Ghana (Meale et al 2012). Meanwhile, as the subject matter by Meale et al (2012) was the evaluation of feed, it does not agree well with this present co-grazing experiment as the focus was to investigate the characteristics of FF inoculants in fermentation of feed samples. Thus, the VFA analysis performed in this present study revealed the capability of microbes in the FF rather than evaluation among pasture that was used as substrate in the in vitro fermentation study.…”

<b>Effect of replacement of sugarcane by oilseed press cakes in greenhouse gases and volatile fatty acids production <i>in vitro

“…The feed ingredients were dried at 55ºC for 24 hours and then ground to paste through a 1 mm screen. Each in vitro incubation was conducted according to the methods reported by Meale, Chaves, Baah, and Mcallister (2012). The entire incubation procedure was repeated twice (i.e., two incubation runs x three replicates per treatment, resulting in a total of six replicate vials per treatment).…”