Evaluation of tropical plants containing tannin on in vitro methanogenesis and fermentation parameters using rumen fluid.

BACKGROUND: Methane (CH(4)) produced during ruminal fermentation represents a loss of 10-11% of gross energy intake. The use of browse species containing tannin as feed supplement for ruminants tends to increase in order to reduce CH(4) production. The present study was conducted to evaluate some tropical plants containing tannin as feed supplement (200 g kg(-1)) on in vitro CH(4) production and fermentation parameters.
RESULTS: The crude protein (CP) content ranged from 87 to 390 g kg(-1) dry matter (DM) and was highest in Sesbania grandiflora (L.) Poiret. The neutral detergent fibre (NDF) concentration was highest in Pennisetum purpureum Schumach (725 g kg(-1) DM) and lowest in S. grandiflora (330 g kg(-1) DM). The ranking order of plants based on their total tannin content was Acacia mangium Willd. > Biophytum petersianum Klotzch > Jatropa curcas Linnaeus > Psidium guajava Linnaeus > Phaleria papuana > Persea americana Mill. > S. grandiflora. Methane gas production after 48 h of incubation was significantly (P < 0.05) lower with inclusion of A. mangium (PP + AM), B. petersianum (PP + BP), J. curcas (PP + JC) or P. guajava (PP + PG) as compared to control feed (PP). There was negative correlation between total tannin content and CH(4) production at 48 h of incubation (r = - 0.76). Concentration NH(3)-N was significantly (P < 0.01) higher with inclusion of S. glandiflora. Inclusion of P. guajava significantly (P < 0.05) suppressed protozoa population by 49.7% relative to control feed (PP).
CONCLUSION: It was concluded that A. mangium, B. petersianum, J. curcas and P. guajava have potential to be used as a feed supplement to reduce CH(4) production in ruminants.