Evaluation of enteric methane production in dairy cows fed Acacia mearnsii.

OBJECTIVES

We investigated the effect of different incorporations of Acacia mearnsii forage (AM) in maize silage or A. mearnsii tannin extract (AME) in pellets on dairy rumen CH4.

MATERIALS AND

METHODS

Using a completely randomized design per experiment, 24 crossbred Holstein-Friesian and Jersey dairy cows per experiment were divided into groups (n = 6 cows per experiment). Dairy cows were fed pellets with 0% (0PEL), 0.75% (0.75PEL), 1.5% (1.5PEL), or 3.0% (3PEL) of AME (Experiment 1). Furthermore, dairy cows were fed 0% (0AM), 5% (5AM), 15% (15AM), or 25% (25AM) of AM in maize silage (Experiment 2). Data sampling period (21 days) of ruminal CH4 and nitrogen (N2), carbon dioxide (CO2), and hydrogen (H2) gases (% vol) was conducted after the adaptation period (14 days) for each experiment.

RESULTS

Enteric CH4 was not affected by AME inclusion, but AM inclusions affected CH4, except for CH4 (% vol per cow per day). The inclusions of 25AM decreased CH4 per nutrient intake (kg/day), such as dry matter (DM), organic matter (OM), crude protein, acid detergent fiber (ADF), and neutral detergent fiber (NDF). In addition, there was a linear and quadratic AM inclusion effect on CH4 per intake of nutrients, including DM, NDF, ADF, and OM.

CONCLUSION

Enteric CH4 was not affected by AME but was decreased by AM in dairy cows.