The role of dried distillers grains plus solubles (DDGS) and associative effects of different levels of grape seed meal (GSM) fortified in DDGS, used as both protein and energy sources in the diet, on ruminal fermentation and microbiota were investigated using rumen-simulation technique. All diets consisted of hay and concentrate mixture with a ratio of 48:52 [dry matter (DM) basis], but were different in the concentrate composition. The control diet contained soybean meal (13.5% of diet DM) and barley grain (37%), whereas DDGS treatments, unfortified DDGS (19.5% of diet DM), or DDGS fortified with GSM, either at 1, 5, 10, or 20% were used entirely in place of soybean meal and part of barley grain at a 19.5 to 25% inclusion level. All diets had similar DM, organic matter, and crude protein contents, but consisted of increasing neutral detergent fiber and decreasing nonfiber carbohydrates levels with DDGS-GSM inclusion. Compared with the soy-based control diet, the unfortified DDGS treatment elevated ammonia concentration (19.1%) of rumen fluid associated with greater crude protein degradation (~19.5%). Methane formation decreased with increasing GSM fortification levels (≥ 5%) in DDGS by which the methane concentration significantly decreased by 18.9 to 23.4 and 12.8 to 17.6% compared with control and unfortified DDGS, respectively. Compared with control, unfortified DDGS decreased butyrate proportion, and GSM fortification in the diet further decreased this variable. The proportions of genus Prevotella and Clostridium cluster XIVa were enhanced by the presence of DDGS without any associative effect of GSM fortification. The abundance of methanogenic archaea was similar, but their composition differed among treatments; whereas Methanosphaera spp. remained unchanged, proportion of Methanobrevibacter spp. decreased in DDGS-based diets, being the lowest with 20% GSM inclusion. The abundance of Ruminococcus flavefaciens, anaerobic fungi, and protozoa were decreased by the GSM inclusion. As revealed by principal component analysis, these variables were the microorganisms associated with the methane formation. Grape seed meal fortification level in the diet decreased DM and organic matter degradation, but this effect was more related to a depression of nonfiber carbohydrates degradation. It can be concluded that DDGS fortified with GSM can favorably modulate ruminal fermentation.

Plant bioactive compounds are currently viewed as possible feed additives in terms of methane mitigation and improvement of ruminal fermentation. A range of analyses, including the botanical characterisation, chemical composition and in vitro efficiency, have to be conducted before testing the compounds in vivo. Therefore, the aims of this study were (1) to identify the main bioactive components of black seed (Nigella sativa) oil (BO) and of the root powder of Ferula elaeochytris (FE), and (2) to investigate their effects on ruminal fermentation in vitro, when supplemented in different dosages to a diet (1 : 1, forage : concentrate), using the rumen simulation technique (Rusitec). Main compounds of BO were thymoquinone and p-cymene and a-pinene in FE. Supplementation of the diet with BO and FE did not affect concentration of volatile fatty acids but ammonia concentrations decreased with both supplements (P < 0.001). No effects of supplements on protozoal counts were detected but in vitro disappearance of DM and organic matter tended to increase with 50 mg/L FE (P < 0.1), compared with the control.

Potential Environmental Benefits of Residual Feed Intake as Strategy to Mitigate Methane Emissions in Sheep

The actual mineral concentration in forage is an important factor for livestock production regardless of the source of variation. Therefore, the aims of this research work were: i) to estimate the mineral soil availability and the forage actual mineral composition status in three grasslands (Ranches), and ii) to identify relationships between soil mineral contents and forage actual mineral concentrations. Soil of Ranch 2 showed better conditions for plant growth than Ranches 1 and 3 soils. In fact, it had higher P, Ca and Mg mean concentrations than the minimum contents used as reference suggesting deficiencies. However, Na and K soil contents were lower than the reference contents in all three Ranches. Macro-minerals P, Ca and Na were at insufficient levels in forage from all three Ranches. Significant correlations (r Pearson) suggest a positive effect of soil P content on forage P and Mg concentrations, and indicate soil P content could affect forage Ca concentration and Ca:P ratio. Other important correlations suggest soil Ca negative effects on forage Ca concentration and Ca:P ratio. Soil available Na was at insufficiency level.

El objetivo de este trabajo fue evaluar el perfil in vitro de nutrientes de bagazo de Agave salmiana (AS) y Agave weberi cela (AWC) como alternativa para la nutrición de los rumiantes. ElbagazoserecogióenJalpa,Zacatecasduranteelaño2010.A partir de las muestras recogidas, se evaluó: materia seca (MS), cenizas, fibra cruda (FC), extracto etéreo (EE), proteína cruda (PC), carbono orgánico total (TOC), detergente neutro de f ibra (DNF), y azúcares reductores totales (ART). Macro y micro- minerales se determinaron por espectroscopia de absorción atómica.Además, se utilizó una técnica de producción de gas in vitro para evaluar la cinética de fermentación, y después de 48 hdeincubacióndelasmuestrasseutilizaronparacuantificarla producción de AGV. La proteína cruda (%) (2.25 vs 2.73), EE (%) (0.274 vs 0.272), CF (%) (22.15 vs 16,58) y cenizas (%) (2.14 vs 1.81) no fueron diferentes estadísticamente (p> 0.05) entre AS y tratamiento AWC. Los valores de DNF (% MS) fueron estadísticamente diferentes (p< 0.05) entre elAS (45.45) y los tratamientosAWC (52.95). No se observaron diferencias enAGVentrebagazodeagaveydefrijol.Losvaloresdecalcio (%) promedio de 3.46 y 1.95 paraAS yAWC, respectivamente. Se concluye que, el bagazo de agave representa una alternativa viable para la alimentación de rumiantes, especialmente en la estación seca.