Effect Of Intraruminal Infussion Of Saturated And Unsaturated Fatty Acids On Organic Matter Degradability, Total Volatile Fatty Acid And Methane Productions In West African Dwarf Sheep

Abstract

This study describes the effect of intraruminal infusion of different proportions of palmitic (saturated fatty acid) and linolenic (unsaturated fatty acid) on rumen degradability of organic matter fraction of Pennisetium purpureum, total volatile fatty acid and total methane productions in West African Dwarf sheep. Five combination proportions of palmitic and linolenic acids viz: 70  % palmitic acid + 30  % linolenic acid, 30  % palmitic acid + 70  % linolenic acid, 50  % palmitic acid + 50  % linolenic acid, 100  % palmitic acid + 0  % linolenic and 0  % palmitic acid + 100  % linolenic acid designated treatments A-E respectively served as the experimental treatments. These treatments were intraruminally infused into five (5) adult WAD sheep of average body weight of 13.49 ± 1.63 kg and the trial performed in a 5 x 5 latin square experimental design. A sixth group of four sheep, that did not receive any fatty acid infusion, served as the control group. The in-sacco technique for degradability studies was adopted in the determination of organic matter disappearance from the rumen at time intervals of 4, 8, 12, 24 and 48 hours in both the experimental and control groups. Appropriate mathematical model for estimation of total volatile fatty acid (VFA) and total methane production were used for determination of VFA and methane productions. The result of the study showed that organic matter degradability was significantly (p < 0.01) highest in treatment A (70  % palmitic acid + 30  % linolenic acid) at 24 hours (84.63 ± 8.6  %) and 48 hours (88.42 ± 4.8  %) compared to other treatments and the control. Higher proportion of linolenic acid (treatments B and E ) significantly (p<0.01) reduced potential  OM degradability at 48 hours with values at 41.08 ± 5.5  % and 23.92 ± 2.4  % respectively. Total VFA production was significantly (p <0.01) increased in treatment A at 24 hours (3.59 ± 0.07 m mol/l) and 48 hours (3.62 ±0.04 m mol/l) compared to other treatments and the control. At same time post incubation, total methane production was significantly (P<0.01) decreased in treatments B (0.39 ± 0.01 mol/hr) and E (0.34 ± 0.006 mol/hr) compared to treatments A (0.52 ± 0.01 mol/hr) which recorded a significant (P<0.01) increase. The study revealed that high proportion of unsaturated fatty acid suppressed rumen fermentation with resultant decrease in organic matter degradability, total VFA and methane productions. The reverse was however the case with high proportions of saturated fatty acids.