title: In-vitrofermentation characteristics and methane reduction potential of mustard cake (Brassica junceaL.).
abstract: OBJECTIVE
  To assess the effect of mustard cake (Brassica junceaL.) levels in concentrate mixtures and in composite feed mixtures (CFMs) onin-vitrofermentation characteristics and methane production.
  
  
  METHODS
  Five concentrate mixtures were prepared with containing 30% oil cake, where linseed cake was replaced by mustard cake at the rate of 0%, 7.5%, 15.0%, 22.5%, and 30% in concentrate mixture. Mustard cake contained glucosinolate 72.58 µmol/g oil free dry matter (DM) and contents in diet were 0, 5.4, 10.9, 16.3, and 21.8 µmol/g of concentrate mixture, respectively. Concentrate mixture containing 15.0% mustard cake was found to produced minimum methane which was then used for the preparation of CFM containing 0%, 25%, 50%, and 75% levels with gram straw.
  
  
  RESULTS
  Increased levels of mustard cake in concentrate mixtures had a linear decrease (p<0.05) in the total gas production, and the 15% inclusion showed lowest methane concentration (quadratic, p<0.01). The degradability of DM and organic matter (OM) of concentrate mixtures did not change, however, pH and NH3-N concentrations of the fermentation medium showed linear (p<0.05) reductions with increased mustard cake levels. Increased levels of 15% mustard cake containing concentrate mixture in CFMs exhibited a trend (p=0.052) of increased gas production, whereas methane concentration in total gas, methane produced and degradability of DM and OM were also displayed a linear increase (p<0.05). However, the pH, NH3-N, and total volatile fatty acid levels decreased linearly (p<0.05) with increased levels of concentrate in CFMs.
  
  
  CONCLUSIONS
  Reduction in methane production was evidenced with the inclusion of mustard cake in concentrate mixture at 15% level, and the CFMs with 25% concentrate, which contained 15% mustard cake, exhibited an improved fermentation and reduced methane production.
authors.affiliation: Division of Nutrition, Feed Resource and Product Technology, Central Institute for Research on Goats, Mathura - 281 122, Uttar Pradesh, India; Division of Animal Nutrition, Indian Veterinary Research Institute, Bareilly - 243 122, Uttar Pradesh, India; Department of Instructional Livestock Farm Complex, College of Veterinary and Animal Sciences, Udgir, Latur - 413 517, Maharashtra, India.
authors.forename: S M
authors.initials: SM
authors.lastname: Durge
authors.affiliation: Division of Nutrition, Feed Resource and Product Technology, Central Institute for Research on Goats, Mathura - 281 122, Uttar Pradesh, India.
authors.forename: M K
authors.initials: MK
authors.lastname: Tripathi
authors.affiliation: Division of Animal Nutrition, Indian Veterinary Research Institute, Bareilly - 243 122, Uttar Pradesh, India.
authors.forename: N
authors.initials: N
authors.lastname: Dutta
keywords: Brassica; glucosinolate; methane; mustard cake; rumen fermentation