title: Effects of different vegetable oils on rumen fermentation and conjugated linoleic acid concentrationin vitro.
abstract: OBJECTIVE
  The objective of this study was to investigate the effect of different vegetable oils on rumen fermentation and concentrations of beneficialcis-9trans-11 C18:2 conjugated linoleic acid (CLA) andtrans-11 C18:1 fatty acid (FA) in the rumen fluid in anin vitrocondition.
  
  
  METHODS
  Six vegetable oils including sunflower, soybean, sesame, rice bran, groundnut, and mustard oils were used at three dose levels (0%, 3% and 4% of substrate dry matter [DM] basis) in three replicates for each treatment in a completely randomized design using 6 × 3 factorial arrangement. Rumen fluid for microbial culture was collected from four goats fed on a diet of concentrate mixture and berseem hay at a ratio of 60:40 on DM basis. Thein vitrofermentation was performed in 100 ml conical flakes containing 50 ml of culture media and 0.5 g of substrates containing 0%, 3% and 4% vegetable oils.
  
  
  RESULTS
  Oils supplementation did not affect (p>0.05)in vitroDM digestibility, and concentrations of total volatile FAs and ammonia-N. Sunflower oil and soybean oil decreased (p<0.05) protozoal numbers with increasing levels of oils. Other oils had less pronounced effect (p>0.05) on protozoal numbers. Bothtrans-11 C18:1 FA andcis-9,trans-11 CLA concentrations were increased (p<0.05) by sunflower and soybean oil supplementation at 4% level with the highest concentration observed for sunflower oil. The addition of other oils did not significantly (p>0.05) increase thetrans-11 C18:1 FA andcis-9,trans-11 CLA concentrations as compared to the control. The concentrations of stearic, oleic, linoleic, and linolenic acids were not altered (p>0.05) due to the addition of any vegetable oils.
  
  
  CONCLUSIONS
  Supplementation of sunflower and soybean oils enhanced beneficialtrans-11 C18:1 FA andcis-9,trans-11 CLA concentrations in rumen fluid, while sesame, rice bran, groundnut, and mustard oils were ineffective in this study.
authors.affiliation: Department of Animal Nutrition, West Bengal University of Animal and Fishery Sciences, Belgachia, Kolkata - 700 037, West Bengal, India.
authors.forename: Amitava
authors.initials: A
authors.lastname: Roy
authors.affiliation: Department of Animal Nutrition, West Bengal University of Animal and Fishery Sciences, Belgachia, Kolkata - 700 037, West Bengal, India.
authors.forename: Guru Prasad
authors.initials: GP
authors.lastname: Mandal
authors.affiliation: Department of Animal Nutrition, West Bengal University of Animal and Fishery Sciences, Belgachia, Kolkata - 700 037, West Bengal, India.
authors.forename: Amlan Kumar
authors.initials: AK
authors.lastname: Patra
keywords: conjugated linoleic acid; goat; rumen fluid; vaccenic acid; vegetable oil