Czech J. Anim. Sci., 2016, 61(6):262-272 | DOI: 10.17221/52/2015-CJAS

Influence of the addition of exogenous xylanase with or without pre-incubation on the in vitro ruminal fermentation of three fibrous feedsOriginal Paper

M.M.Y. Elghandour¹, A.E. Kholif², J. Hernández³, M.D. Mariezcurrena⁴, S. López⁵, L.M. Camacho⁶, O. Márquez⁷, A.Z.M. Salem¹

¹ Faculty of Veterinary Medicine and Animal Science, Autonomous University of the State of Mexico, Toluca, Mexico

² Dairy Science Department, National Research Centre, Giza, Egypt

³ Faculty of Engineering and Science, Autonomous University of Tamaulipas, Victoria City, Mexico

⁴ Faculty of Agricultural Sciences, Autonomous University of the State of Mexico, Toluca, Mexico

⁵ Department of Animal Production, Mountain Livestock Institute, CSIC-University of Leon, Leon, Spain

⁶ Faculty of Veterinary and Animal Science, Autonomous University of Guerrero, Altamirano, Mexico

⁷ University Center of Amecameca, Autonomous University of the State of Mexico, Amecameca, Mexico

The effects of the exogenous fibrolytic enzyme (ENZ) commercial preparation Dyadic^® xylanase PLUS (Dyadic International, Inc., Jupiter, USA), containing endo-1,4-β-d-xylanase, on ruminal fermentation of maize stover, oat straw, and sugarcane bagasse were examined using the in vitro gas production (GP) technique. The ENZ commercial preparation was added at 0 (control), 60 (low), 120 (medium), and 240 (high) µg/g dry matter of substrate, and at two times of application (direct addition just before fermentation or with a 72-h pre-incubation before fermentation). Ruminal GP volumes were recorded at 2, 4, 6, 8, 10, 12, 14, 24, and 48 h of incubation, and substrate degradability and concentration of fermentation end-products (volatile fatty acids, ammonia, methane) in the cultures were determined at 48 h of incubation. Increased (P < 0.05) GP volume was observed in fibrous feeds treated with ENZ compared with untreated substrates. The pre-incubation vs the direct addition of ENZ resulted in greater GP volume (P < 0.05) with the three tested feeds. Enzyme addition decreased (P < 0.05) rumen pH compared to control when maize stover and sugarcane bagasse were incubated. Ammonia-N and total volatile fatty acids (VFA) were not affected (P > 0.05) by ENZ application in maize stover and oat straw. However, total and individual VFA concentrations, and CH₄ and CO₂ volumes were greater (P < 0.05) when sugarcane bagasse was incubated with 240 µg ENZ/g (P < 0.05). It can be concluded that the application of endo-1,4-β-d-xylanase enhances rumen fermentation of roughages, although the magnitude of the effects depends on the fibrous substrate fermented, the time of application, and the amount of enzyme added.

Keywords: roughage; gas production; fibre degradation; rumen; fibrolytic enzyme

Published: June 30, 2016  Show citation