title: Evaluation of Different Yeast Species for Improving In vitro Fermentation of Cereal Straws.
abstract: Information on the effects of different yeast species on ruminal fermentation is limited. This experiment was conducted in a 3×4 factorial arrangement to explore and compare the effects of addition of three different live yeast species (Candida utilis 1314, Saccharomyces cerevisiae 1355, and Candida tropicalis 1254) at four doses (0, 0.25×10(7), 0.50×10(7), and 0.75×10(7) colony-forming unit [cfu]) on in vitro gas production kinetics, fiber degradation, methane production and ruminal fermentation characteristics of maize stover, and rice straw by mixed rumen microorganisms in dairy cows. The maximum gas production (Vf), dry matter disappearance (IVDMD), neutral detergent fiber disappearance (IVNDFD), and methane production in C. utilis group were less (p<0.01) than other two live yeast supplemented groups. The inclusion of S. cerevisiae reduced (p<0.01) the concentrations of ammonia nitrogen (NH3-N), isobutyrate, and isovalerate compared to the other two yeast groups. C. tropicalis addition generally enhanced (p<0.05) IVDMD and IVNDFD. The NH3-N concentration and CH4 production were increased (p<0.05) by the addition of S. cerevisiae and C. tropicalis compared with the control. Supplementation of three yeast species decreased (p<0.05) or numerically decreased the ratio of acetate to propionate. The current results indicate that C. tropicalis is more preferred as yeast culture supplements, and its optimal dose should be 0.25×10(7) cfu/500 mg substrates in vitro.
authors.affiliation: University of the Chinese Academy of Sciences, Beijing 100049, China; Lethbridge Research Centre, Agriculture and Agri-Food Canada, Lethbridge T1J 4B1, Canada.
authors.forename: Zuo
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Lethbridge Research Centre, Agriculture and Agri-Food Canada, Lethbridge T1J 4B1, Canada.
authors.forename: Zhixiong
authors.initials: Z
authors.lastname: He
authors.affiliation: Lethbridge Research Centre, Agriculture and Agri-Food Canada, Lethbridge T1J 4B1, Canada.
authors.forename: Karen A
authors.initials: KA
authors.lastname: Beauchemin
authors.affiliation: University of the Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Shaoxun
authors.initials: S
authors.lastname: Tang
authors.affiliation: University of the Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Chuanshe
authors.initials: C
authors.lastname: Zhou
authors.affiliation: University of the Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Xuefeng
authors.initials: X
authors.lastname: Han
authors.affiliation: University of the Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Min
authors.initials: M
authors.lastname: Wang
authors.affiliation: University of the Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Jinhe
authors.initials: J
authors.lastname: Kang
authors.affiliation: Animal Production and Health Section, Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture, International Atomic Energy Agency, Vienna A-1400, Austria.
authors.forename: Nicholas E
authors.initials: NE
authors.lastname: Odongo
authors.affiliation: University of the Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Zhiliang
authors.initials: Z
authors.lastname: Tan
keywords: Fiber Degradation; In vitro Fermentation; Live Yeast; Methane; Volatile Fatty Acids