Influence of inoculated maize silage and sunflower oil on the in vitro fermentation, ciliate population and fatty acid outputs in the rumen fluid collected from sheep

Abstract

The effect of maize silage (MS) supplemented with sunflower oil (SO) on the rumen fermentation parameters, growth of ciliate population and fatty acid outputs was investigated for 72 hours using a batch culture fermentation technique. The rumen fluid from ruminally fistulated sheep was mixed with McDougall's buffer (1:1) and added (35 ml) to fermentation bottles containing 1.5 g (0.38 g of DM) of MS with or without SO (30 g/kg of DM). Four types of MS were used: uninoculated (MS) or inoculated with Lactobacillus plantarum CCM 4000 (MS+LP), Lactobacillus fermentum LF2 (MS+LF) or Enterococcus faecium CCM 4231 (MS+EF) in simultaneous incubations at 39 ± 0.5°C for 72 h in vitro. Total gas production was decreased by SO (by 16-17%) in MS and all inoculated MS. Methane production was not significantly influenced by SO. The concentration of total volatile fatty acids, molar proportions of acetate, propionate and n-butyrate were influenced by SO (P < 0.05; P < 0.01; P < 0.001). SO had no significant effect on the total ciliate number and growth of the examined ciliate species Entodinium spp., Dasytricha ruminantium, Polyplastron multivesiculatum, Enoploplastron triloricatum and Diplodinium denticulatum. The number of Dasytricha ruminantium with MS+LP was higher (P < 0.01) as compared to MS. Outputs of trans vaccenic acid (TVA), linoleic acid, conjugated linoleic acid (CLA) and α-linolenic acid were influenced by SO (P < 0.05; P < 0.01; P < 0.001). However, the output of CLA was increased only in MS+LF (P < 0.001). It can be concluded that the supplementation of sunflower oil into maize silage is not effective as dietary antiprotozoal agents in a short-time interval, but it might positively affect the rumen bacterial population and activities. Sunflower oil with inoculated and uninoculated maize silage could be effective for an increase of TVA in the rumen fluid of sheep.

Keywords

• maize silage
• inoculation
• lipid metabolism
• ciliate protozoa
• in vitro