Effect of dietary olive oil and palm oil on rumen bacterial composition in dairy cows

Abstract

The rumen bacteria play a major role in lipid metabolism. Bacteria remove the double bonds of unsaturated fatty acids resulting in the production of saturated fatty acids, which are incorporated in milk. Crude olive oil (rich in unsaturated fatty acids) represents a potentially valuable feed source for dairy cows that might enhance the human-health beneficial composition of milk and dairy products. This project studied the effect of supplementing dairy cow diets with olive oil (OO) and palm oil (HVO) on rumen microbiota. For 63 days the animals were fed a control diet (basal diet) with no added lipid and two fat-supplemented diets (30 g kg−1 DM). Rumen sampling were performed at the onset of the experiment and every 21 days for 63 days using a rumen scoop. Total microbial DNA was extracted from ruminal samples for high-throughput sequencing of the 16S rRNA gene through Illumina MiSeq platform. Results revealed the dominance of phyla Firmicutes and Bacteroidetes. Firmicutes was the most prevalent phyla in diet control (75.2 %), OO (71.1 %) and HVO (75.2 %). At genus level Succiniclasticum and Prevotella were the dominant genera, belonging to Firmicutes and Bacteroidetes respectively. Succiniclasticum decrease significantly their relative abundance during OO supplementation (p)