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 diferent 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 % linolenicacid, 50 % palmitic acid + 50 % linolenic acid, 100 % palmitic acid + 0 % linolenic and 0 % palmitic acid + 100 % linolenic acid designated treatments A-E respectivey served as the experimental treatments. These treatments were intraruminally infused into five (5) adult WAD sheep of average body weight of 1349 ± 163 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 dsappearance from the rumen at tme intervals of 4, 8, 12, 24 and 48 hours in both the experimental and control groups. Appropriate mathematical model for estimation o total volatile fatty acid (VFA) and total methane production were used for determination o VFA and methane productions. The result of the study showed that organic matter degradability was signifcantly (p < 001) highest in treatment A (70 % palmitic acid + 30 % linolenic acid) at 24 hours (8463± 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 degradabiy at 48 hours wth values at 41.08 ± 5.5 % and 23.92 ± 2.4 % respectvely. Tota VFA production was signiicanty (p <0.01) increased ntreatment 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 o saturated fatty acids.

Keywords: Fatty acids, Degradability, Volatile fatty acid, Methane, WAD sheep