Changes in in Vitro Methane Production and Fatty Acid Profiles in Response to Cakalang Fish Oil Supplementation
Abstract: This experiment was
conducted to determine the effect of cakalang fish oil addition in ruminant
feed on in vitro methane production and fatty acid profiles. This experiment
consisted of four treatments which were R0 : feed composing of forage and
concentrate at a ratio of 60% : 40% without cakalang fish oil (CFO) addition as
control feed; R1: R0 added with CFO at 2.5%; R2: R0 added with CFO at 5%, and
R3: R0 added with CFO at 7.5%. Fermentation with rumen fluid was done using the
Hohenheim Gas Test (HGT); feeds were incubated at 39 oC for 72 hours. At the
end of fermentation, samples were obtained and methane production and fatty
acid profiles were determined. The experiment was conducted in completely
randomised design with four replications. Data were analysed using analysis of
variance and differences among treatment means were analysed using Duncan
multiple range test. Results showed that CFO supplementation affected
(P<0.05) methane production, protozoa numbers and NH3 concentration; whereas
the other parameters, i.e. VFA concentration, pH, and microbial protein were
not affected. Some fatty acid profiles were influenced by treatments, such as
palmitic, stearic, oleic, linoleic, and linolenic (P<0.05), while others,
i.e. lauric and miristic were not affected. It is concluded that the best level
of CFO supplementation is 5% as this level reduces methane production and
increases unsaturated fatty acids without any negative effects on other
variables measured.
Keywords: cakalang fish oil;
fatty acids; in vitro fermentation; methane; gas test
Author: E. H. B. Sondakh, M.
R. Waani, J. A. D. Kalele
Journal Code: jppeternakangg170070