Effect of Plant Secondary Metabolites on Rumen Methanogens and Methane Emissions by Ruminants

  • Devki Nandan Kamra
  • Mahesh Pawar
  • Beddyuti Singh


Methanogenesis occurs in the rumen to take care of reducing power generated during fermentation of feed and accounts for a significant loss of energy offered to the ruminants as feed. Once carbon dioxide is reduced to methane, it cannot be oxidized to release energy under the anaerobic conditions prevailing in the rumen. To save this energy loss, several chemicals have been tested and some of them are very effective in selectively inhibiting methanogenesis, but these chemicals cannot be used in practical feeding of livestock due to their adverse effects on other rumen microbes, health of the animals and the quality of livestock products. Therefore, plants containing secondary metabolites might be superior feed additives to control methanogenesis without affecting other microbes of the rumen. In vitro screening experiments conducted in many laboratories have indicated that methanogenesis can be inhibited by inclusion of plants/plant extracts in the substrate. Some of the plants which showed in vitro methane inhibition are : Allium sativum, Azadirachta indica, Emblica officinalis, Eugenia jambolana, Ficus benghalensis, Foeniculum vulgare, Lotus pedunculatus, Mangifera indica, Ocimum sanctum, Populus deltoides, Psidium guajava, Quercus incana, Sapindus mukorossi, Sapindus rarak, Sesbania sesban, Syzygium aromaticum, Trachyspermum ammi, Terminalia chebula and Yucca schidigera, but some of them do have adverse effects on rumen fermentation and feed digestibility. Several of the above plants have been tested in vivo as feed additives in different ruminants either alone or in a combination and have shown significant decrease in in vivo methane emission and no adverse effect on feed utilization when used at the rate of 1–2% of dry matter intake. There is a need to screen larger number of plants containing secondary metabolites and to study the effect of feeding these compounds on the feed utilization and the quality of livestock products.


Plant secondary metabolites Essential oils Saponins Tannins Ruminal microbiota 



Acid detergent fibre


Average daily gain




Carbon dioxide


Condensed tannins




Digested dry matter


Denaturing gradient gel electrophoresis


Dry matter


Dry matter intake


Embden-Meyerhof pathway


Essential oils


Essential oil mixture


Hyper ammonia producing


Molecular weight


Nicotinamide adenine dinucleotide


Nicotinamide adenine dinucleotide phosphate


Neutral detergent fibre


Ammonia nitrogen




Organic matter


Polymerase chain reaction


Plant secondary metabolites


Recombinant deoxyribonucleic acid




Tea saponins


Volatile fatty acids


  1. Agarwal N, Kamra DN, Chaudhary LC (2006) Effect of Sapindus mukorossi extract on in vitro methanogenesis and fermentation characteristics in buffalo rumen liquor. J Appl Anim Res 30:1–4Google Scholar
  2. Agarwal N, Kamra DN, Chatterjee PN et al (2008) Changes in microbial profile, methanogenesis and fermentation of green forages with buffalo rumen liquor as influenced by 2-bromoethanesulphonic acid. Asian-Aust J Anim Sci 21:818–823Google Scholar
  3. Agarwal N, Chandra S, Kumar R et al (2009) Effect of peppermint (Mentha piperita) oil on in vitro methanogenesis and fermentation of feed with buffalo rumen liquor. Anim Feed Sci Technol 148:321–327CrossRefGoogle Scholar
  4. Ando S, Nishida T, Ishida M et al (2003) Effect of peppermint feeding on the digestibility, ruminal fermentation and protozoa. Livest Prod Sci 82:245–248CrossRefGoogle Scholar
  5. Bampidis VA, Christodoulou V, Florou-Paneri P et al (2005) Effect of dietary dried oregano leaves supplementation on performance and carcass characteristics of growing lambs. Anim Feed Sci Technol 121:285–295CrossRefGoogle Scholar
  6. Bate-Smith EC (1972) Tannins in herbaceous leguminosae. Phytochemistry 12:907CrossRefGoogle Scholar
  7. Beauchemin KA, McGinn SM (2006) Methane emissions from beef cattle: effects of fumaric acid, essential oil, and canola oil. J Anim Sci 84:1489–1496PubMedGoogle Scholar
  8. Beauchemin KA, McGinn SM, Martinez TF et al (2007) Use of condensed tannin extract from quebracho trees to reduce methane emissions from cattle. J Anim Sci 85:1990–1996PubMedCrossRefGoogle Scholar
  9. Benchaar C, Duynisveld JL, Charmley E (2006a) Effects of monensin and increasing dose levels of a mixture of essential oil compounds on intake, digestion and growth performance of beef cattle. Can J Anim Sci 86:91–96Google Scholar
  10. Benchaar C, Petit HV, Berthiaume R et al (2006b) Effects of addition of essential oils and monensin premix on digestion, ruminal fermentation, milk production, and milk composition in dairy cows. J Dairy Sci 89:4352–4364PubMedCrossRefGoogle Scholar
  11. Benchaar C, Chaves AV, Fraser GR et al (2007a) Effects of essential oils and their components on in vitro rumen microbial fermentation. Can J Anim Sci 87:413–419CrossRefGoogle Scholar
  12. Benchaar C, Petit HV, Berthiaume R et al (2007b) Effects of essential oils on digestion, ruminal fermentation, rumen microbial populations, milk production, and milk composition in dairy cows fed alfalfa silage or corn silage. J Dairy Sci 90:886–897PubMedCrossRefGoogle Scholar
  13. Bodas R, L’opez S, Fern’andez M et al (2008) In vitro screening of the potential of numerous plant species as antimethanogenic feed additives for ruminants. Anim Feed Sci Technol 145:245–258CrossRefGoogle Scholar
  14. Broudiscou LP, Papon Y, Broudiscou AF (2000) Effects of dry plant extracts on fermentation and methanogenesis in continuous culture of rumen microbes. Anim Feed Sci Technol 87:263–277CrossRefGoogle Scholar
  15. Busquet M, Calsamiglia S, Ferret A et al (2005a) Effects of cinnamaldehyde and garlic oil on rumen microbial fermentation in a dual flow continuous culture. J Dairy Sci 88:2508–2516PubMedCrossRefGoogle Scholar
  16. Busquet M, Calsamiglia S, Ferret A et al (2005b) Effect of garlic oil and four of its compounds on rumen microbial fermentation. J Dairy Sci 88:4393–4404PubMedCrossRefGoogle Scholar
  17. Busquet M, Calsamiglia S, Ferret A et al (2006) Plant extracts affect in vitro rumen microbial fermentation. J Dairy Sci 89:761–771PubMedCrossRefGoogle Scholar
  18. Calsamiglia S, Busquet M, Cardozo PW et al (2007) Essential oils as modifiers of rumen microbial fermentation. J Dairy Sci 90:2580–2595PubMedCrossRefGoogle Scholar
  19. Cardozo PW, Calsamiglia S, Ferret A et al (2004) Effects of natural plant extracts on protein degradation and fermentation profiles in continuous culture. J Anim Sci 82:3230–3236PubMedGoogle Scholar
  20. Cardozo PW, Calsamiglia S, Ferret A et al (2006) Effects of alfalfa extract, anise, capsicum and a mixture of cinnamaldehyde and eugenol on ruminal fermentation and protein degradation in beef heifers fed a high concentrate diet. J Anim Sci 84:2801–2808PubMedCrossRefGoogle Scholar
  21. Chaudhary LC, Verma V, Sharma A et al (2009) Effect of feeding a plant mixture containing secondary metabolites on in vivo methane emission and rumen fermentation. In: Proceedings of ANA World Conference, vol II, New Delhi, 14–16 Feb 2009, p 213Google Scholar
  22. Chaves AV, He ML, Yang WZ et al (2008a) Effects of essential oils on proteolytic, deaminative and methanogenic activities of mixed ruminal bacteria. Can J Anim Sci 89:97–104CrossRefGoogle Scholar
  23. Chaves AV, Stanford K, Dugan MER et al (2008b) Effects of cinnamaldehyde, garlic and juniper berry essential oils on rumen fermentation, blood metabolites, growth performance and carcass characteristics of growing lambs. Livest Sci 117:215–224CrossRefGoogle Scholar
  24. Chaves AV, Stanford K, Gibson LL et al (2008c) Effects of carvacrol and cinnamaldehyde on intake, rumen fermentation, growth performance and carcass characteristics of growing lambs. Anim Feed Sci Technol 145:396–408CrossRefGoogle Scholar
  25. Cox SD, Mann CM, Markam JL (2001) Interaction between components of the essential oil of Melaleuca alternifolia. J Appl Microbiol 91:492–497PubMedCrossRefGoogle Scholar
  26. Craig WJ (1999) Health-promoting properties of common herbs. Am J Clin Nutr 70:491–499Google Scholar
  27. Davidson PM, Naidu AS (2000) Phyto-phenols. In: Naidu AS (ed) Natural food antimicrobial systems. CRC Press, Boca Raton, pp 265–293Google Scholar
  28. Dorman JJD, Deans SG (2000) Antimicrobial agents from plants: antibacterial activity of plant volatile oils. J Appl Microbiol 88:308–316PubMedCrossRefGoogle Scholar
  29. El Lakany AM, AbdelKader MS, Hammoda HM et al (1997) A new flavone glycoside with antimicrobial activity from Carduus pycnocephalus. Pharmazie 52:78–79PubMedGoogle Scholar
  30. Esmaeili A, Rustaiyan A, Nadimi M (2005) Volatile constituents of Centaurea depressa MB and Carduuspycnocephalus L. two compositae herbs growing wild in Iran. J Essent Oil Res 17:539–541Google Scholar
  31. Evans JD, Martin SA (2000) Effects of thymol on ruminal microorganisms. Curr Microbiol 41:336–340PubMedCrossRefGoogle Scholar
  32. Finlay B, Esteban G, Clarke KJ et al (1994) Some rumen ciliates have endosymbiotic methanogens. FEMS Microbiol Lett 117:157–162PubMedCrossRefGoogle Scholar
  33. Flachowsky G (2009) Comments on in vitro studies with methane inhibitors. Anim Feed Sci Technol 151:337–339CrossRefGoogle Scholar
  34. Gershenzon J, Croteau R (1991) Terpenoids. In: Rosenthal GA, Berenbaum MR (eds) Herbivores: their interactions with secondary plant metabolites, vol 1. Academic, San Diego, pp 165–219Google Scholar
  35. Goel G, Makkar HPS, Becker K (2008) Effect of Sesbania sesban and Carduus pycnocephalus leaves and fenugreek seeds and their extracts on partitioning of nutrient from roughage and concentrate based feeds to methane. Anim Feed Sci Technol 147:72–89CrossRefGoogle Scholar
  36. Griffin SG, Wyllie SG, Markham JL et al (1999) The role of structure and molecular properties of terpenoids in determining their antimicrobial activity. Flavour Fragr J 14:322–332CrossRefGoogle Scholar
  37. Hart KJ, Yanez-Ruiz DR, Duval SM et al (2008) Plant extracts to manipulate rumen fermentation. Anim Feed Sci Technol 147:8–35CrossRefGoogle Scholar
  38. Haslam E (1982) Proanthocyanidins. In: Habrone JB, Mabrey TJ (eds) The flavonoids: advances in research. Chapman and Hall, London. J Nutr 51:493–504Google Scholar
  39. Hernandez F, Madrid J, Garcia V et al (2004) Influence of two plant extract on broiler performance, digestibility, and digestive organ size. Poult Sci 83:169–174PubMedGoogle Scholar
  40. Hess HD, Kreuzer M, Diaz TE et al (2003) Saponin rich tropical fruits affect fermentation and methanogenesis in faunation and defaunated rumen fluid. Anim Feed Sci Technol 109(1–4):79–94CrossRefGoogle Scholar
  41. Horvath PJ (1981) The nutritional and ecological significance of acer-tannins and related polyphenols. M.Sc. thesis, Cornell University, Ithaca, New York, USAGoogle Scholar
  42. Hristov AN, McAllister TA, Van Herk FH et al (1999) Effect of Yucca schidigera on ruminal fermentation and nutrient digestion in heifers. J Anim Sci 77:2554–2563CrossRefGoogle Scholar
  43. Hristov AN, Ivan M, Neill L et al (2003) Evaluation of several potential bioactive agents for reducing protozoal activity in vitro. Anim Feed Sci Technol 105:163–184CrossRefGoogle Scholar
  44. Huang XD, Liang JB, Tan HY et al (2011) Effects of Leucaena condensed tannins of differing molecular weights on in vitro CH4 production. Anim Feed Sci Technol 166–167:373–376CrossRefGoogle Scholar
  45. Ikonen A, Tahvanainen J, Roininen H (2002) Phenolic secondary compounds as determinants of the host plant preferences of the leaf beetle, Agelastica alni. Chemoecology 12:125–131CrossRefGoogle Scholar
  46. Iwashina T (2003) The flavonoids occurring in plants and their functions and activities to other organisms. Plant Cell Physiol 44:S6Google Scholar
  47. Johnson KA, Johnson DE (1995) Methane emission from cattle. J Anim Sci 73:2483–2492PubMedGoogle Scholar
  48. Kamra DN, Agarwal N, Chaudhary LC (2006) Inhibition of ruminal methanogenesis by tropical plants containing secondary compounds. Int Congr Ser 1293:156–163CrossRefGoogle Scholar
  49. Kamra DN, Patra AK, Chatterjee PN et al (2008) Effect of plant extract on methanogenesis and microbial profile of the rumen of buffalo: a brief overview. Aust J Exp Agric 48:175–178CrossRefGoogle Scholar
  50. Kamra DN, Perera ANF, Xie Z-Q et al (2009) The use of plant secondary metabolites as medicine and feed additives for eco-friendly livestock production. In: Scaife JR, Vercoe PE (eds) Harvesting knowledge – pharming opportunities. British Society of Animal Science, Edinburgh, pp 8–20Google Scholar
  51. Kumar R, Kamra DN, Agarwal N et al (2009) Effect of eucalyptus (Eucalyptus globulus) oil on in vitro methanogenesis and fermentation of feed with buffalo rumen liquor. Anim Nutr Feed Technol 9:237–243Google Scholar
  52. Kung L Jr, Williams P, Schmidt RJ et al (2008) A blend of essential plant oils used as an additive to alter silage fermentation or used as a feed additive for lactating dairy cows. J Dairy Sci 91:4793–4800PubMedCrossRefGoogle Scholar
  53. Lila ZA, Mohammed N, Kanda S et al (2003) Effect of α-cyclodextrin allyl isothiocyanate on ruminal microbial methane production in vitro. Anim Sci J 74:321–326CrossRefGoogle Scholar
  54. Macheboeuf D, Morgavi DP, Papon Y et al (2008) Dose-response effects of essential oils on in vitro fermentation activity of the rumen microbial population. Anim Feed Sci Technol 145:335–350CrossRefGoogle Scholar
  55. Makkar HPS (2003) Effects and fate of tannins in ruminant animals, adaptation to tannins, and strategies to overcome detrimental effects of feeding tannin-rich feeds. Small Rumin Res 49:241–256CrossRefGoogle Scholar
  56. Makkar HPS, Becker K (1997) Degradation of quillaja saponins by mixed culture of rumen microbes. Lett Appl Microbiol 25:243–245PubMedCrossRefGoogle Scholar
  57. Mao H-L, Wang J-K, Zhou Y-Y et al (2011) Effects of addition of tea saponins and soybean oil on methane production, fermentation and microbial population in the rumen of growing lambs. Livest Sci 129:56–62CrossRefGoogle Scholar
  58. Mathison GW, Soofi-Siawah R, Klita PT (1999) Degradability of alfalfa saponins in the digestive tract of sheep and their rate of accumulation in rumen fluid. Can J Anim Sci 79:315–319CrossRefGoogle Scholar
  59. McIntosh FM, Williams P, Losa R et al (2003) Effects of essential oils on ruminal metabolism and their protein metabolism. Appl Environ Microbiol 69:5011–5014PubMedCrossRefGoogle Scholar
  60. McLeod MN (1974) Plant tannins-their role in forage quality. Nutr Abstr Rev 44:803–815Google Scholar
  61. McSweeney CS, Palmer B, Bunch R et al (2001) Effect of tropical forage calliandra on microbial protein synthesis and ecology in the rumen. J Appl Microbiol 90:78–88PubMedCrossRefGoogle Scholar
  62. Mohammed R, Zhou M, Koenig KM et al (2011) Evaluation of rumen methanogen diversity in cattle fed diets containing dry corn distillers grains and condensed tannins using PCR-DGGE and qRT-PCR analyses. Anim Feed Sci Technol 166–167:122–131CrossRefGoogle Scholar
  63. Newbold CJ, Lassalas B, Jouany JP (1995) The importance of methanogens associated with ciliate protozoa in ruminal methane production in vitro. Lett Appl Microbiol 21:230–234PubMedCrossRefGoogle Scholar
  64. Newbold CJ, El-Hassan SM, Wang J et al (1997) Influence of foliage for African multipurpose trees on activity of rumen protozoa and bacteria. Br J Nutr 78:237–249PubMedCrossRefGoogle Scholar
  65. Newbold CJ, McIntosh FM, Williams P et al (2004) Effects of a specific blend of essential oil compounds on rumen fermentation. Anim Feed Sci Technol 114:105–112CrossRefGoogle Scholar
  66. Oh HK, Jones MB, Longhurst WM (1967) Effect of various essential oils isolated from Douglas fir needles upon sheep and deer rumen microbial activity. Appl Microbiol 15:777–784PubMedGoogle Scholar
  67. Oh HK, Jones MB, Longhurst WM (1968) Comparison of rumen microbial inhibition resulting from various essential oils isolated from relatively unpalatable plant species. Appl Microbiol 16:39–44PubMedGoogle Scholar
  68. Patra AK, Kamra DN, Agarwal N (2006a) Effect of plant extracts on in vitro methanogenesis enzyme activities and fermentation of feed in the rumen liquor of buffalo. Anim Feed Sci Technol 128:276–291CrossRefGoogle Scholar
  69. Patra AK, Kamra DN, Agarwal N (2006b) Effect of plants containing metabolites on in vitro methanogenesis, enzyme profile and fermentation of feed with rumen liquor of buffalo. Anim Nutr Feed Technol 6:203–213Google Scholar
  70. Patra AK, Kamra DN, Agarwal N (2008) Effect of leaf extracts on in vitro rumen fermentation and methanogenesis with rumen liquor of buffalo. Indian J Anim Sci 78:91–96Google Scholar
  71. Patra AK, Kamra DN, Agarwal N (2009) Effects of extracts of spices on rumen methanogenesis, enzyme activities and fermentation of feeds in vitro. J Sci Food Agric 90:511–520Google Scholar
  72. Patra AK, Kamra DN, Bhar R et al (2010) Effect of Terminalia chebula and Allium sativum on in vivo methane emission by sheep. J Anim Physiol Anim Nutr 95:187–191. doi:10.1111/j.1439-0396.2010.01039.x CrossRefGoogle Scholar
  73. Pawar M (2011) Assessment of essential oils as rumen modifiers and their effect on feed conversion efficiency in buffaloes. Ph.D. thesis, Indian Veterinary Research Institute, Deemed University, Izatnagar, IndiaGoogle Scholar
  74. Pellikaan WF, Stringano E, Leenaars J et al (2011) Evaluating effects of tannins on extent and rate of in vitro gas and CH4 production using an automated pressure evaluation system (APES). Anim Feed Sci Technol 166–167:377–390CrossRefGoogle Scholar
  75. Puchala R, Min BR, Goetsch AL et al (2005) The effect of a condensed tannin-containing forage on methane emission by goats. J Anim Sci 83:182–186PubMedGoogle Scholar
  76. Ramakrishna RR, Platel K, Srinivasan K (2003) In vitro influence of species and spice-active principles on digestive enzymes of rat pancreas and small intestine. Nahrung 47:408–412CrossRefGoogle Scholar
  77. Reuter HD, Koch JP, Lawson L (1996) Therapeutic effects and applications of garlic and its preparations. In: Koch HP, Lawson LD (eds) Garlic: the science and therapeutic application of Allium sativum L. and related species. Williams & Wilkins, Baltimore, pp 135–212Google Scholar
  78. Sallam SMA, Bueno ICS, Brigide P et al (2009) Efficacy of eucalyptus oil on in vitro ruminal fermentation and methane production. Options Mediterraneennes 85:267–272Google Scholar
  79. Sallam S, Bueno I, Nasser MEA et al (2010) Effect of eucalyptus (Eucalyptus citriodora) fresh or residue leaves on methane emission in vitro. Ital J Anim Sci 9(3):4081Google Scholar
  80. Sallam SMA, Abdelgaleil SAM, Bueno ICS et al (2011) Effect of some essential oils on in vitro methane emission. Arch Anim Nutr 65(3):203–214PubMedCrossRefGoogle Scholar
  81. Soltan MA (2009) Effect of essential oils supplementation on growth performance, nutrient digestibility, health condition of Holstein male calves during pre- and post-weaning periods. Pak J Nutr 8:642–652CrossRefGoogle Scholar
  82. Swain T (1979) Tannins and lignins. In: Rosenthal GA, Janzen DH (eds) Herbivores – their interaction with secondary plant metabolites. Academic, New York, pp 657–682Google Scholar
  83. Tan HY, Sieo CC, Abdullah N et al (2011) Effects of condensed tannins from Leucaena on methane production, rumen fermentation and populations of methanogens and protozoa in vitro. Anim Feed Sci Technol 169:185–193CrossRefGoogle Scholar
  84. Tatsouka N, Hara K, Mlkuni K et al (2008) Effects of the essential oil cyclodextrin complexes on ruminal methane production in vitro. Anim Sci J 79:68–75CrossRefGoogle Scholar
  85. Tavendale MH, Meagher LP, Pacheco D et al (2005) Methane production from in vitro rumen incubations with Lotus pedunculatus and Medicago sativa, and effects of extractable condensed tannin fractions on methanogenesis. Anim Feed Sci Technol 123–124:403–419CrossRefGoogle Scholar
  86. Thalib A, Widiawati Y, Hamid H et al (1996) The effects of saponins from Sapindus rarak fruit on rumen microbes and performance of sheep. Jurnal Ilmu Ternak dan Veteriner 2(1):17–21Google Scholar
  87. Ultee A, Kets EPW, Smid EJ (1999) Mechanisms of action of carvacrol on the food borne pathogen Bacillus cereus. Appl Environ Microbiol 65:4606–4610PubMedGoogle Scholar
  88. Verma V, Chaudhary LC, Agarwal N et al (2009) Effect of feed additives on methane emission and rumen microbial profile in buffalo. In: Proceedings of ANA World Conference, vol 2, New Delhi, 14–16 Feb 2009, p 212Google Scholar
  89. Wallace RJ (2004) Antimicrobial properties of plant secondary metabolites. Proc Nutr Soc 63:621–629PubMedCrossRefGoogle Scholar
  90. Wang Y, McAllister TA, Newbold CJ et al (1998) Effect of Yucca schidigera extract on fermentation and degradation of steroidal saponins in the rumen simulation technique (RUSITEC). Anim Feed Sci Technol 74:143–153CrossRefGoogle Scholar
  91. Wang Y, McAllister TA, Yanke LJ et al (2000) In vitro effects of steroidal saponins from Yucca schidigera extract on rumen microbial protein synthesis and ruminal fermentation. J Sci Food Agric 80:2114–2122CrossRefGoogle Scholar
  92. Wang CJ, Wang SP, Zhou H (2009) Influences of flavomycin, ropadiar and saponin on nutrient digestibility, rumen fermentation and methane emission from sheep. Anim Feed Sci Technol 148:157–166CrossRefGoogle Scholar
  93. White T (1957) Tannins – their occurrence and significance. J Sci Food Agric 8:377–385CrossRefGoogle Scholar
  94. Williams CM, Eun J-S, MacAdam JW et al (2011) Effects of forage legumes containing condensed tannins on methane and ammonia production in continuous cultures of mixed ruminal microorganisms. Anim Feed Sci Technol 166–167:364–372CrossRefGoogle Scholar
  95. Yang WZ, Benchaar C, Ametaj BN (2007) Effects of garlic and juniper berry essential oils on ruminal fermentation and on the site and extent of digestion in lactating cows. J Dairy Sci 90:5671–5681PubMedCrossRefGoogle Scholar
  96. Yang WZ, Ametaj BN, Benchaar C et al (2010) Cinnamaldehyde in feedlot cattle diets: intake, growth performance, carcass characteristics, and blood metabolites. J Anim Sci 88:1082–1092PubMedCrossRefGoogle Scholar
  97. Zadbuke SS (2009) Effect of plant secondary metabolites on microbial profile and methanogenesis in rumen and nutrient utilization in buffaloes. Ph.D. thesis, Indian Veterinary Research Institute, Deemed University, Izatnagar, IndiaGoogle Scholar
  98. Zhou Y-Y, Mao H-L, Jiang F et al (2010) Tea saponins inhibit ruminal methane emission through the inhibitory effect on protozoa in Hu sheep. In: Proceedings of Fourth Greenhouse Gases and Animal Agriculture Conference, Banff, Canada, pp 159–160Google Scholar
  99. Zhou YY, Mao HL, Jiang F et al (2011) Inhibition of rumen methanogenesis by tea saponins with reference to fermentation pattern and microbial communities in Hu sheep. Anim Feed Sci Technol 166–167:93–100CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media Dordrecht 2012

Authors and Affiliations

  • Devki Nandan Kamra
    • 1
  • Mahesh Pawar
    • 1
  • Beddyuti Singh
    • 1
  1. 1.Division of Animal NutritionIndian Veterinary Research InstituteIzatnagarIndia

Personalised recommendations