Effects of extracts of spices on rumen methanogenesis, enzyme activities and fermentation of feeds in vitro.
BACKGROUND
An experiment was conducted to study the effects of boiling water, methanol and ethanol extracts (0, 0.25 and 0.50 mL) of seeds of Foeniculum vulgare (fennel), flower buds of Syzygium aromaticum (clove), bulbs of Allium sativum (garlic), bulbs of Allium cepa (onion) and roots of Zingiber officinalis (ginger) on rumen methanogenesis, fibrolytic enzyme activities and fermentation characteristics in vitro.


RESULTS
Ethanol and methanol extracts of fennel, clove and garlic at 0.50 mL and clove at 0.25 mL inhibited (P < 0.05) methane production. Carboxymethylcellulase activity was reduced (P < 0.05) by ethanol and methanol extracts (0.50 mL) of fennel and clove (0.25 and 0.50 mL). The extracts of clove reduced (0.25 and 0.50 mL) xylanase and acetylesterase activities, and the fennel extract (0.50 mL) reduced (P < 0.05) xylanase activity. However, the extracts of garlic (0.50 mL) increased (P < 0.05) acetylesterase activity. Concentrations of volatile fatty acids were reduced (P < 0.05) by the extracts of garlic and onion. The extracts of garlic caused a decrease (P < 0.05) in acetate:propionate ratio (A:P) at 0.50 mL, whereas A:P was increased (P < 0.05) by the inclusion of 0.50 mL extracts of clove. Methanol and ethanol extracts of clove decreased (P < 0.05) in vitro organic matter degradability. Extracts (0.50 mL) of clove decreased (P < 0.05) the numbers of total protozoa, small entodiniomorphs and holotrichs, whereas extracts of onion, ginger and garlic enhanced (P < 0.05) protozoal numbers (both entodiniomorphs and holotrichs).


CONCLUSIONS
Ethanol and methanol extracts of fennel and garlic have potential to inhibit rumen methanogenesis without adversely affecting rumen fermentation.
Patra
Amlan Kumar
AK
Centre of Advanced Studies in Animal Nutrition, Rumen Microbiology Lab, Indian Veterinary Research Institute, Izatnagar, Bareilly, UP 243122, India. patra amlan@yahoo.com
Kamra
Devki Nandan
DN
Agarwal
Neeta
N
D019342:Acetic Acid / Q000378:metabolism; D000821:Animal Feed; D000818:Animals; D002020:Buffaloes; D004798:Enzymes / Q000378:metabolism*; D056890:Eukaryota; D005232:Fatty Acids, Volatile / Q000378:metabolism*; D005285:Fermentation; D019684:Magnoliopsida / Q000201:enzymology*; D008697:Methane / Q000096:biosynthesis*; D010936:Plant Extracts / Q000494:pharmacology*; D018514:Plant Structures; D011422:Propionates / Q000378:metabolism; D012417:Rumen / Q000187:drug effects* / Q000378:metabolism / Q000469:parasitology; D017365:Spices
D004798:Enzymes; D005232:Fatty Acids, Volatile; D010936:Plant Extracts; D011422:Propionates; C029658:propionic acid; D008697:Methane; D019342:Acetic Acid