Enteric Methane Emission from Cattle Grazing Systems with Cover Crops and Legume-Grass Pasture.

This study aims to quantify enteric methane (CH) emission and dry matter intake (DMI) in beef steers under two rotational grazing systems: (i) a mixture of cover crops (vetch + ryegrass + forage radish) (CC) and (ii) alfalfa and fescue pasture (AFP). Eighteen Hereford steers were divided into two groups (nine steers per group), assigned to either the CC or AFP. Methane emissions were measured using the SF tracer technique.

Improving the accuracy of beef cattle methane inventories in Latin America and Caribbean countries.

On-farm methane (CH) emissions need to be estimated accurately so that the mitigation effect of recommended practices can be accounted for. In the present study prediction equations for enteric CH have been developed in lieu of expensive animal measurement approaches. Our objectives were to: (1) compile a dataset from individual beef cattle data for the Latin America and Caribbean (LAC) region; (2) determine main predictors of CH emission variables; (3) develop and cross-validate prediction models according to dietary forage content (DFC); and (4) compare the predictive ability of these newly-developed models with extant equations reported in literature, including those currently used for CH inventories in LAC countries.

Llama and sheep ruminal fluid digestive capacity by in vitro gas production technique.

Background: The in vitro gas production technique has been used to evaluate forage fermentation kinetics. However, individual and animal species variation can change fermentation patterns due to differences in ruminal environment and microbiota. The aim was to verify whether rumen inoculum (RI) of llama had superior intrinsic digestion capacity and reduced methane (CH ) production compared to sheep RI using fescue and paspalum hay as substrates.

Dynamics of the ruminal microbial ecosystem, and inhibition of methanogenesis and propiogenesis in response to nitrate feeding to Holstein calves.

It is known that nitrate inhibits ruminal methanogenesis, mainly through competition with hydrogenotrophic methanogens for available hydrogen (H) and also through toxic effects on the methanogens. However, there is limited knowledge about its effects on the others members of ruminal microbiota and their metabolites. In this study, we investigated the effects of dietary nitrate inclusion on enteric methane (CH) emission, temporal changes in ruminal microbiota, and fermentation in Holstein calves.

Ruminal effects of excessive dietary sulphur in feedlot cattle.

Sulphur (S) dietary excess can limit productive performance and increase polioencephalomalacia (PEM) incidence in feedlot cattle (FC). Sulphur excess ingested is transformed to hydrogen sulphide (H S) by sulfo-reducing ruminal bacteria (SRB), being high ruminal H S concentration responsible for aforementioned damages. As the ruminal mechanisms involved in H S concentrations increase have not been elucidated, this study aimed to evaluate the ruminal environment, and the association between ruminal H S and dissimilatory SRB (DSRB) concentration in FC experimentally subjected to S dietary excess.

Changes in hematological, biochemical, and blood gases parameters in response to progressive inclusion of nitrate in the diet of Holstein calves.

Background And Aim: Nitrate (NO ) reduces enteric methane emissions and could be a source of non-protein nitrogen in ruminant feeds. Nonetheless, it has a potential toxic effect that could compromise animal health and production. The purpose of this study was to determine the effects of progressive inclusion of NO in the diet on the hematological, biochemical, and blood gases parameters, in turn, the effects on feed intake and live weight gain (LWG) in Holstein calves.

The first complete genomic structure of Butyrivibrio fibrisolvens and its chromid.

Butyrivibrio fibrisolvens forms part of the gastrointestinal microbiome of ruminants and other mammals, including humans. Indeed, it is one of the most common bacteria found in the rumen and plays an important role in ruminal fermentation of polysaccharides, yet, to date, there is no closed reference genome published for this species in any ruminant animal. We successfully assembled the nearly complete genome sequence of B.

LAMP technology: Rapid identification of Brucella and Mycobacterium avium subsp. paratuberculosis.

In this study, we developed new sets of primers to detect Brucella spp. and M. avium subsp.

Detection of fiber-digesting bacteria in the forestomach contents of llamas (Lama glama) by PCR.

The high fibrolytic activity and large biomass of strictly-anaerobic bacteria that inhabit the rumen makes them primarily responsible for the degradation of the forage consumed by ruminants. Llamas feed mainly on low quality fibrous roughages that are digested by an active and diverse microflora. The products of this fermentation are volatile fatty acids and microbial biomass, which will be used by the animals.