“…Results from previous studies suggested that feeding forages that contain bioactive CT to ruminants effectively inhibits CH 4 produced during enteric fermentation (Huang et al, 2011;Pellikaan et al, 2011;Puchala et al, 2012). A major question raised by these reports is: what causes CT from some plant sources to be bioactive (Cenci et al, 2007;Brunet et al, 2008;Terrill et al, 2009), whereas CT from others demonstrate almost no bioactivity (Pomroy and Adlington, 2006;Whitley et al, 2009) in the ruminant animal? Molecular weight could be an important factor in the bioactivity of CT, such that as molecular weight of CT increases, bioactivity also increases (Bate-Smith, 1973;Peleg et al, 1999).…”