In vitro fermentation, digestibility and methane production of tropical perennial grass species

Abstract

Abstract. This study characterised 16 tropical perennial grass species in terms of in vitro methane output and related their digestibility and rumen fermentation with methane output. The grass samples were collected, dried in a forced oven, and ground and analysed for nutrient composition. In vitro gas production and organic matter digestibility (IVOMD) were determined using rumen fluid collected, strained and anaerobically prepared. A semi-automated system was used to measure gas production through in vitro incubation at 398C. Anthephora argentea and Stipagrostis ciliate produced the highest concentration of methane in terms of g kg -1 digestible dry matter (DDM) and g kg -1 digestible organic matter (IVOMD). Cenchrus ciliaris, Setaria verticillata and Panicum coloratum produced the lowest (P < 0.05) methane when expressed in terms of g kg -1 DDM and g kg -1 IVOMD. Ash, ether extract, non-fibrous carbohydrate, neutral and acid detergent insoluble nitrogen, and crude protein were negatively correlated with methane production. Methane production positively correlated with neutral and acid detergent fibre, cellulose and hemicellulose. It is important to focus on screening and selecting perennial grass with higher nitrogen content and low methane production to mitigate methane production under tropical conditions.

Methanogenic potential of forages consumed throughout the year by cattle in a Sahelian pastoral area

“…Our results also showed a strong relationship between CH 4 production per gram DM and NDF concentration. This result agrees with results of Gemeda and Hassen (2014) who studied 16 grass species in the arid region of Kalahari with comparable climatic conditions, but not with those observed by Baccouche et al (2014) who performed in vitro incubations of 83 forages, of which 35 were grasses and legumes, harvested in the Ferlo region as in the present study, or those by Macheboeuf et al (2014) who studied 156 temperate plants, of which only one was grass and 13 were legumes. Our results are especially surprising because CH 4 production from forages depend both on their NDF concentration and on their digestibility, which are the two main drivers of hydrogen production from carbohydrate fermentation (Archimède et al 2011).…”

Differences in the nutrient concentrations, in vitro methanogenic potential and other fermentative traits of tropical grasses and legumes for beef production systems in northern Australia

“…We identified differences in nutritive values, fermentability and methanogenic potential amongst selected forages, with some plants producing twice as much CH 4 as others. The nutritive profiles and fermentability in other tropical plants has been reported previously, but this is the first attempt to conduct a systematic and controlled study and examine temporal variations in these parameters.…”

“…Several potential CH 4 abatement strategies for ruminants grazing tropical forages have been considered, including variability in plant nutritive value and fermentability features, especially amount of CH 4 produced when digested by rumen microbes (‘methanogenic potential’) . However, such attributes, in particular methanogenic potential, of legumes and grasses in northern Australia are unknown.…”

Effect of supplementing or treating <i>Eragrostis curvula</i> hay with urea or nitrate on its digestibility and <i>in vitro</i> fermentation

“…The availability of rumen ammonia is often a primary deficit when protein-deficient feedstuffs such as grass hays are fed to ruminants, limiting microbial biomass production, digestibility, and feed intake (Hao Trinh et al, 2009). Enteric methane emissions are dependent on the amount of feed consumed by the animal and the composition of the diet, with lower emission values from concentrate than from roughage-based diets (Mirzaei-Aghsaghali & Meheri-Sis, 2011;Gemeda & Hassen, 2014a). Methane per unit of organic matter degraded could be up to two times higher in tropical forages than in legumes (Widiawati et al, 2007;Gemeda & Hassen, 2014a).…”

“…Enteric methane emissions are dependent on the amount of feed consumed by the animal and the composition of the diet, with lower emission values from concentrate than from roughage-based diets (Mirzaei-Aghsaghali & Meheri-Sis, 2011;Gemeda & Hassen, 2014a). Methane per unit of organic matter degraded could be up to two times higher in tropical forages than in legumes (Widiawati et al, 2007;Gemeda & Hassen, 2014a). In the past, many studies have been conducted globally on improving the feeding value of roughages (Wanapat et al, 2009;Shreck, 2013;Gemeda et al, 2014b).…”