Efeitos de dietas contendo Leucaena leucocephala e Saccharomyces cerevisiae sobre a fermentação ruminal e a emissão de gás metano em bovinos

Abstract

Efeitos de dietas contendoRESUMO -Este trabalho foi realizado com o objetivo de avaliar os efeitos do uso de leucena e levedura em dietas para bovinos sobre o metabolismo ruminal, incluindo o pH e as produções de ácido graxos voláteis (AGV), amônia e gás metano.Quatro bovinos machos com 800 kg e fistulados no rúmen foram mantidos em quadrado latino 4 × 4, em arranjo fatorial 2 × 2, composto de dois níveis de leucena (20 e 50% MS) e feno de capim coast-cross na presença ou ausência de levedura.Não houve influência das dietas nos valores médios de pH (média 6,82) e nas concentrações de amônia no rúmen, que variaram de 18 a 21 mg/100 mL. Houve interação entre níveis de leucena e levedura na concentração total de AGV. As dietas não diferiram quanto à concentração de ácido acético, mas os animais alimentados com a dieta com 50% de leucena e contendo levedura apresentaram maiores concentrações médias de ácido propiônico (média 19,14 mM). A emissão de metano reduziu em12,3% em relação à mesma dieta sem levedura e em 17,2% quando os animais foram alimentados com 20% de leucena com levedura. Verificou-se efeito associativo de leucena, quando fornecida em alto nível na dieta (50% MS), e levedura na redução da emissão de metano e na melhoria no padrão de fermentação no rúmen, o que pode reduzir as perdas de energia e melhorar eficiência energética do animal. Palavras-chave: ácidos graxos voláteis, gases ruminais, levedura, metabolismo ruminal Effects of leucaena and yeast on rumen fermentation and methane emissions in cattleABSTRACT -This research was to evaluate the effect of Leucaena (Leucaena leucocephala) and yeast (Saccharomyces cerevisiae) in diets for bovines on ruminal metabolism, including pH, volatile fatty acids, and ammonia and methane production.Four crossbred male cattle (800 kg LW) rumen cannulated were distributed to a 4 × 4 Latin Square design, in 2 × 2 factorial arrangement, composed by two levels of Leucaena (20% and 50% DM) and coast-cross grass hay, with or without yeast. No differences were observed in rumen pH (mean 6.82) and ammonia concentrations that varied from 18.71 to 21.28 mg/100 mL of ruminal fluid. There was interaction between Leucaena levels and yeast in the total concentrations of VFA. No differences were observed in the concentrations of acetic acid, but the animals fed 50% of Leucaena with yeast showed higher propionic acid concentration (19.14 mM). Methane emissions were reduced by 12.3% in relation to the same diet without yeast and in 17.2% when the animals were fed 20% of Leucaena with yeast. There was a noticeable associative effect of Leucaena when fed in high level (50% DM) and yeast in the reduction of methane emission and better rumen fermentation with possible reduction of energy loss and better energy efficiency for the animals.

Relationship between residual feed intake and enteric methane emission in Nellore cattle

“…The methane emission data (g/d) are similar to those reported by Possenti et al (2008), who observed emission of 147.5 g CH 4 /d in cattle fed coast-cross hay with 200 g/kg of leucaena, and lower than those estimated by Johnson and Johnson (1995) for beef cattle (164 to 194 g CH 4 /d). The values expressed as kg/year (51-53 kg CH 4 /kg year) agree with the estimates reported by Cederberg et al (2009) for young cattle in Brazil (47-56 kg CH 4 /year), and by the IPCC (2006), which estimated an average emission of 49 kg CH 4 /year for young cattle (230 kg BW) in Latin America.…”

Methane Emission of Cattle Fed Urochloa brizantha Hay Harvested at Different Stages

“…For hay harvested at 45 days of forage growth, the methane emission was higher (P < 0.05) compared to the other treatments; whereas the hay harvested at 15 days showed the lowest emission. Similar results were found by Possenti et al (2008), who in trials with two levels of leucaena hay in the diet (20 or 50% MS), observed emissions of 20.49 and 16.90 g kg -1 DMI, respectively. In the present trial, the same effect (P < 0.05) was also found for methane emissions expressed as g kg -1 of organic matter intake; this revealed a similar increase when animals received hay harvested at 45 days of forage growth.…”

Active yeast (Saccharomyces cerevisiae) supplementation improves digestibility of lamb diet¹

“…The values were much higher than the minimum value of 13mg/100mL which, according to [16], could affect availability of nitrogen for microorganisms and impair intake and fiber digestibility. These results are similar to those found by [19] who worked with addition of S. cerevisiae in diet of cattle fed with grass hay and increasing levels of leucena, and also observed increase in rumen ammonia concentrations 2 hours after feeding, with constant decline until eight hours after feeding, returning to values close to time zero.…”