Forage Intake of \u3ci\u3eNellore\u3c/i\u3e Steers Grazing a \u3ci\u3eCajanus Cajan\u3c/i\u3eLegume-Grass Intercropped Pasture

This study evaluated forage, supplement, and total (forage + supplement) dry matter intake (DMI, expressed as kg/day and as percentage of average live weight, %ALW) of Nellore steers in different production systems, including a Cajanus cajan (Pigeon pea) legume-grass intercropped pasture by using external (titanium dioxide, TiO2) and internal (indigestible neutral detergent fiber, iNDF) markers. The experiment was carried out at Embrapa Southeast Livestock, São Carlos, SP, Brazil, in the rainy (January) and dry (July) seasons of 2021. Eighteen animals Nellore steers were randomly distributed into three treatments with three replications (1.5 ha paddocks each): 1) degraded pasture of Urochloa decumbens cv. Basilisk (DEG); 2) Intercropped legume-grass pasture composed by U. decumbens cv. Basilisk, U. brizantha cv. Marandu and Cajanus cajan cv. BRS Mandarin limed and fertilized with P, K, S, micronutrients (INT) and 3) mixture pasture of U. decumbens cv. Basilisk and U. brizantha cv. Marandu limed and fertilized with P, K, S, micronutrients and 200 kg N-urea ha-1 year-1 (REC). The statistical model considered treatment and season as fixed effects, and the treatment×season interaction was tested. Data were submitted to analysis of variance (PROC MIXED) and means were compared by the Fisher test at 5%. Significant treatment×season interaction was found (P \u3c 0.05). During the rainy season lower values of forage and total DMI were found for the INT treatment when compared to REC. However, during the dry season, the treatment with Pigeon pea inclusion (INT) presented higher values of forage and total DMI. The DEG and REC system steers reduced their DMI from the rainy season to the dry season, even receiving a mineral energetic-protein supplement with urea, while the INT steers maintained DMI between seasons without receiving the energetic-protein supplement. These results highlight the potential of including Pigeon pea in pasture-based systems, especially during the dry season when tropical grasses present low nutritional quality and forage availability

Nitrate: its role on ruminal fermentation of beef cattle under intensified grazing system.

Rumen fermentation it is one of the contributors to the greenhouse gases emission (GHG) that causes global warming, and due to that reason livestock production is scrutinized and questioned all around the world on how GHG emissions from this subsector can be mitigated. A range of techniques have been studied by animal scientist, at nutritional level, to mitigate methane emission. Nitrate is of them, and it has a double important role on rumen fermentation, acting as a source of non-protein nitrogen, and as an electron sink path that allows the redirection of hydrogen to nitrate reduction, instead of being used in the methanogenesis process, and thus reducing methane emission. The partial results here presented shows that nitrate does not affect forage, supplement, and total dry mater intake, and neither short chain fatty acids production, however, methane emission (g.kg.day-1) and CO2eq emissions per kg. head-1d-1were reduced when nitrate was added in the diet. Thus, nitrate has the ability in changing rumen fermentation, which besides acting as source of non-protein nitrogen, also mitigate anthropic GHG emissions from enteric fermentation

Efeito do consumo de taninos condensados na emissão de CH4 entérico por novilhos Nelore em pastagem consorciada.

Atualmente, o Brasil possui o maior rebanho comercial de bovinos do mundo sendo mantidos, em grande parte, sobre pastagens tropicais, necessitando reduzir as emissões de CH4 entérico

Relação acetato: propionato no líquido ruminal de novilhos Nelore em diferentes sistemas de produção a pasto.

Visando sustentabilidade, pesquisas têm buscado alimentos e estratégias que modulem a fermentação ruminal, melhorando o aproveitamento dos nutrientes e diminuindo a produção de gases do efeito estufa (GEE) nos sistemas de produção animal

Intensidade de emissão de CH4 por novilhos da raça Nelore em pastagem consorciada com Cajanus Cajan.

O metano (CH4) entérico é o principal gás de efeito estufa (GEE) emitido pelo setor agropecuário no Brasil

Short-term use of monensin and tannins as feed additives on digestibility and methanogenesis in cattle.

The objective was to assess the effects short-term use of monensin and Acacia mearnsii tannins as feed additives on nutrient intake, digestibility, and CH4 production in cattle. Six rumen-cannulated Holstein cows were distributed in two 3×3 Latin square experimental design, and each experimental period lasted 21 days. The basal diet was composed of corn silage and concentrate in a 50:50 dry matter (DM) basis proportion. Treatments were control, monensin (18 mg kg?1 of DM), and tannin-rich extract from Acacia mearnsii (total tannins equivalent to 6 g kg?1 of DM). Nutrient intake and apparent digestibility coefficients were not affected by the addition of monensin or tannins to diets. However, tannins showed a tendency to reduce crude protein digestibility. Monensin decreased CH4 emission by 25.6% (g kg?1 of body weight) compared with the control treatment. Monensin is more effective than Acacia mearnsii tannins in reducing CH4 emissions in the short term, considering a diet of the same roughage:concentrate proportion for cattle

Uso de leguminosas na dieta de ruminantes: adaptação às mudanças climáticas e mitigação da emissão de gases de efeito estufa.

Frente aos evidentes sinais de mudanças climáticas, o uso de leguminosas forrageiras na dieta de ruminantes torna-se de grande relevância para a otimização da produção animal, o uso racional dos recursos naturais e a manutenção do meio ambiente. Ao longo deste capítulo serão abordadas as características de cultura e de desempenho animal referente, principalmente, ao consórcio de gramíneas com as leguminosas macrotiloma ou feijão guandu. Observou-se que ambas as leguminosas, quando consorciadas, demonstraram serem eficientes em reduzir a emissão de metano quando levado em consideração o desempenho animal (dados preliminares), sendo, portanto, uma boa estratégia para mitigação das emissões de gases de efeito estufa

Cajanus cajan consumption on performance and mitigation of enteric methane emissions from Nellore Steers.

Solutions to more productive grazing systems capable of mitigating enteric methane (CH4) emissions are needed. This study aimed to evaluate the performance and the enteric CH4 emission of Nellore steers in three different continuous grazing systems, including Cajanus cajan consortium