Associative effects between Chlorella vulgaris microalgae and Moringa oleifera leaf silage used at different levels decreased in vitro ruminal greenhouse gas production and altered ruminal fermentation.

Moringa oleifera leaf silage and Chlorella vulgaris microalgae mixture used at different levels replacing concentrate feed mixture in the diets of ruminant were evaluated using an in vitro gas production technique. C. vulgaris was included in rations at 1, 2, and 3% concentrations. The concentrate feed mixture was replaced by M. oleifera silage up to 100%. Productions of total gas, methane (CH4), and carbon dioxide (CO2) and ruminal fermentation were measured. Interactions between M. oleifera and C. vulgaris levels were observed for the rate of total gas production, lag time of CH4 production, pH, and concentrations of ammonia-N (NH3-N), total volatile fatty acid (VFA), and propionate. The lower level of C. vulgaris increased total gas production and decreased CH4 and CO2 production as well as improved nutrient degradability compared to the other levels of C. vulgaris which showed less improvement in these parameters. The replacement levels of concentrate at 10 to 40% with M. oleifera linearly increased the asymptotic total gas production and degradabilities of dry matter and acid detergent fiber (P<0.05), while the replacement levels of 80 to 100% lowered the asymptotic (P<0.01) for the ration containing 1% C. vulgaris. Rations containing M. oleifera linearly increased the lag time of total gas production (P<0.05), neutral detergent fiber degradability, and ruminal bacteria count and decreased the asymptotic CH4 and CO2 production and ruminal protozoal count (P<0.05). For the rations containing 2 and 3% C. vulgaris, M. oleifera linearly (P<0.01) decreased the asymptotic total gas, CH4 and CO2 production, and ruminal protozoal count. The lag time of CH4 production was not affected at 1% C. vulgaris, but reduced linearly at 2% and 3% C. vulgaris. Ruminal pH was not affected by M. oleifera, but was increased by C. vulgaris at 3% level. Overall, M. oleifera in the ration containing C. vulgaris at all levels increased ruminal NH3-N concentration; however, C. vulgaris at 2% level and M. oleifera at levels up to 40% lowered NH3-N concentration. M. oleifera rations with 1% and 2% C. vulgaris increased the concentrations of total VFA and propionate, whereas these variables were not affected at 3% C. vulgaris level. In conclusion, replacement of concentrate mixture with M. oleifera at 30% level and C. vulgaris at 1% in the diet due to associative effects may improve ruminal fermentation and feed degradability while decreasing CH4 production.

Efeito do ambiente ruminal sobre a degradabilidade de colmos da cana-de-açúcar / Effect of the rumen environment on sugarcane stems degradability

Avaliou-se o efeito do ambiente ruminal sobre a degradação da FDN de 12 cultivares de cana. As dietas continham: 87,1% de cana (Cana) ou 42,0% de cana e 58,0% de concentrado com milho (Milho) ou polpa cítrica (Polpa). Seis vacas com cânula ruminal formaram quadrados latinos 3x3. Por 11 dias de cada período experimental, o consumo de matéria seca foi fixado em 1,2% do peso vivo. No dia 12, baixo pH ruminal foi induzido no Milho e na Polpa por infusão intrarruminal de milho ou polpa cítrica. Simultaneamente, ureia foi adicionada ao rúmen em todos os tratamentos. Sacos de náilon contendo os cultivares foram incubados por 24h nos dias 11 e 12. O pH ruminal no dia 11 foi 7,01 e NH3 foi 3,4, 4,4 e 6,2mg/dL para Cana, Milho e Polpa, respectivamente. O pH no dia 12 foi 6,98 para Cana, 6,49 para Milho e 6,04 para Polpa, e NH3 foi 13,0mg/dL. Para Cana, a degradabilidade ruminal da FDN foi 21% no dia 11 e 28% no dia 12; para Milho e Polpa esta foi ao redor de 21% em ambos os dias. O ordenamento dos cultivares por degradabilidade ruminal da FDN foi similar nos ambientes ruminais distintos.(AU)

The effect of the rumen environment on NDF degradability of 12 sugarcane cultivars was evaluated. Diets contained: 87.1% of sugarcane (Cane) or 42.0% of sugarcane and 58.0% of concentrates with corn (Corn) or citrus pulp (Citrus). Six rumen cannulated cows formed 3x3 Latin Squares. For 11 days of each experimental period, the intake of dry matter was fixed at 1.2% of body weight. On day 12, low ruminal pH was induced on Corn and Citrus by pulse dosing corn or citrus pulp into the rumen. Simultaneously, urea was added to the rumen in all treatments. Nylon bags containing the cultivars were incubated for 24 h on the 11th and 12th days. Rumen pH on day 11 was 7.01 and NH3 was 3.4, 4.4 and 6.2 mg/dl for Cane, Corn and Citrus, respectively. Ruminal pH on day 12 was 6.98 for Cane, 6.49 for Corn and 6.04 for Citrus and NH3 was 13.0 mg/dl. For Cane, ruminal NDF degradability was 21% on day 11 and 28% on day 12, for Corn and Citrus it was around 21% in both days. The ranking of cultivars based on ruminal NDF degradability was similar in distinct rumen environments.(AU)