title: Effects of Candida norvegensis Live Cells on In vitro Oat Straw Rumen Fermentation.
abstract: This study evaluated the effect of Candida norvegensis (C. norvegensis) viable yeast culture on in vitro ruminal fermentation of oat straw. Ruminal fluid was mixed with buffer solution (1:2) and anaerobically incubated with or without yeast at 39°C for 0, 4, 8, 16, and 24 h. A fully randomized design was used. There was a decrease in lactic acid (quadratic, p = 0.01), pH, (quadratic, p = 0.02), and yeasts counts (linear, p<0.01) across fermentation times. However, in vitro dry matter disappearance (IVDMD) and ammonia-N increased across fermentation times (quadratic; p<0.01 and p<0.02, respectively). Addition of yeast cells caused a decrease in pH values compared over all fermentation times (p<0.01), and lactic acid decreased at 12 h (p = 0.05). Meanwhile, yeast counts increased (p = 0.01) at 12 h. C. norvegensis increased ammonia-N at 4, 8, 12, and 24 h (p<0.01), and IVDMD of oat straw increased at 8, 12, and 24 h (p<0.01) of fermentation. Yeast cells increased acetate (p<0.01), propionate (p<0.03), and butyrate (p<0.03) at 8 h, while valeriate and isovaleriate increased at 8, 12, and 24 h (p<0.01). The yeast did not affect cellulolytic bacteria (p = 0.05), but cellulolytic fungi increased at 4 and 8 h (p<0.01), whereas production of methane decreased (p<0.01) at 8 h. It is concluded that addition of C. norvegensis to in vitro oat straw fermentation increased ruminal fermentation parameters as well as microbial growth with reduction of methane production. Additionally, yeast inoculum also improved IVDMD.
authors.affiliation: Department of Veterinary Medicine, Multidisciplinary Division, Autonomous University of Juarez City, Nuevo Casas Grandes, Chih. 31803, México.
authors.forename: Oscar
authors.initials: O
authors.lastname: Ruiz
authors.affiliation: Department of Veterinary Medicine, Multidisciplinary Division, Autonomous University of Juarez City, Nuevo Casas Grandes, Chih. 31803, México.
authors.forename: Yamicela
authors.initials: Y
authors.lastname: Castillo
authors.affiliation: Department of Veterinary Medicine, Multidisciplinary Division, Autonomous University of Juarez City, Nuevo Casas Grandes, Chih. 31803, México.
authors.forename: Claudio
authors.initials: C
authors.lastname: Arzola
authors.affiliation: Department of Veterinary Medicine, Multidisciplinary Division, Autonomous University of Juarez City, Nuevo Casas Grandes, Chih. 31803, México.
authors.forename: Eduviges
authors.initials: E
authors.lastname: Burrola
authors.affiliation: College of Veterinary Medicine and Animal Science, Autonomous University of Tamaulipas, Cd. Victoria, Tamps. 87000, México.
authors.forename: Jaime
authors.initials: J
authors.lastname: Salinas
authors.affiliation: Department of Veterinary Medicine, Multidisciplinary Division, Autonomous University of Juarez City, Nuevo Casas Grandes, Chih. 31803, México.
authors.forename: Agustín
authors.initials: A
authors.lastname: Corral
authors.affiliation: Agricultural Research Service, Southern Plains Research Center, Food and Feed Safety Research Unit, United States Department of Agriculture, College Station, TX 77843, USA.
authors.forename: Michael E
authors.initials: ME
authors.lastname: Hume
authors.affiliation: College of Veterinary Medicine and Animal Science, Juarez University of Durango State, Durango, Dgo. 34000, Mexico.
authors.forename: Manuel
authors.initials: M
authors.lastname: Murillo
authors.affiliation: Department of Veterinary Medicine, Multidisciplinary Division, Autonomous University of Juarez City, Nuevo Casas Grandes, Chih. 31803, México.
authors.forename: Mateo
authors.initials: M
authors.lastname: Itza
keywords: Fermentation; Methane; Oat Straw; Rumen; Yeast