Methane emissions and estimates of ruminal fermentation parameters in beef cattle fed different dietary concentrate levels

Abstract

Using sorghum silage, the effect of roughage/concentrate ratios was evaluated on nutrient intake, digestibility, ruminal parameters and methane production by beef cattle. Three treatments (0, 30 and 60% of concentrate in DM of the diet) were distributed in three Latin squares, with nine animals and three periods. Dry matter intake increased as the grain concentration in diet increased; pH showed opposite behavior. Methane emissions were lower for animals fed the diet exclusively with sorghum silage as compared with those fed 30% of concentrate, but was similar to that of animals receiving 60% of concentrate. Losses of ingested gross energy as methane were reduced by 33% when grain concentration was increased in the diet. Concentrations of propionic and butyric acids were greater in diets with grain concentrate; acetic acid concentration was not affected. Concentrate in diet increases available energy for the metabolism, measured by lower losses of ingested gross energy as ruminal methane.

Effects of feed restriction and forage:concentrate ratio on digestibility, methane emission, and energy utilization by goats

“…) is consistent with previous studies (Lovett et al, 2003;Sauvant and Giger-Reverdin, 2007;Pedreira et al, 2013). As a matter of fact, the increment in concentrate levels from 25% to 50% replaces structural carbohydrates (cellulose, hemicellulose) from forages with non-structural carbohydrates (starch and sugars) present in most highenergy concentrates, inducing an increase in feed intake, rates of ruminal fermentation and feed turnover, with a consequent raise in CH 4 production (Martin et al, 2010).…”

“…As a matter of fact, the increment in concentrate levels from 25% to 50% replaces structural carbohydrates (cellulose, hemicellulose) from forages with non-structural carbohydrates (starch and sugars) present in most highenergy concentrates, inducing an increase in feed intake, rates of ruminal fermentation and feed turnover, with a consequent raise in CH 4 production (Martin et al, 2010). Above 50% concentrate, modifications of rumen physicochemical conditions and microbial populations lead to a shift in volatile fatty acid (VFA) production from acetate towards propionate (Pedreira et al, 2013;Ribeiro et al, 2015). This results in low acetate:propionate ratio concomitant with a reduced ruminal pH and protozoal number, which have been suggested to inhibit growth and/or activity of methanogens (Hegarty, 1999;Aguerre et al, 2011) and of cellulolytic bacteria (Brossard et al, 2004).…”

Development of methane conversion factor models for Zebu beef cattle fed low‐quality crop residues and by‐products in tropical regions

“…Beyond the scope of our study, as the available data are limited, such an improvement still needs cattle fed on tropical pastures as well a tier 3 model that includes a dynamic and mechanistic model of fermentation biochemistry in the enteric to calculate enteric methane emission inventories, instead of a tier 2 one (Bannink et al., ). The Y m tabulation for the cattle fed blooming grasses, legumes, and high‐quality crop residues should be related to the IPCC's data because there is evidence in Brazil and Australia that the Y m response to this diet is rather similar given the overall range of uncertainty (Kennedy & Charmley, ; Pedreira et al., ; Tomkins et al., ). Additionally, a main reason for this difference is the degree to which Y m depends on feed quality (Jaurena et al., ; Kurihara et al., ; Lassey, ).…”

Methane emission factors for enteric fermentation in beef cattle using IPCC Tier-2 method in Indonesia

“…Other reason is the imported beef cattle uses good quality feed (high concentrate fed) which produces low methane per unit dry matter of feed digested (Migwi et al 2011a;Migwi et al 2011b;Pedreira et al 2013;Beauchemin & McGinn 2005).…”