Substitution of Saturated with Unsaturated Lipid Extracts Affects the Fatty Acids Compositions and Hematology in African Catfish, <i>Clarias gariepinus</i>

Abstract

The high cost of fish oil and fishmeal has necessitated the search for alternative ingredients. Palm oil and sesame oil are plausible alternatives to fish oil. Palm oil is saturated while sesame oil is unsaturated. Five experimental diets were made with varying inclusion of crude sesame and palm oil extract. The inclusion percentages of crude sesame extract (CSE) and crude palm extract (CPE), CSE: CPE, were as follows; Feed 1, 25:5; Feed 2, 20:10; Feed 3, 15:15; Feed 4, 10:5; Feed 5, 5:25 and Feed 6(commercial feed). African catfish fingerlings were stocked in aquaria tanks in three replication. The fish were fed to satiation for 70 days with the feeds. After 70 days of feeding experiment, results showed that alanine amino transferase and aspartate amino transferase were both lowest for catfish fed feed F1, F2 and F3. The catfish had significantly higher digestibility for crude sesame extract (CSE) (93.34±0.22 %) than for crude palm extract, (CPE) 78.98 ± 0.11%. Consequently, treatment Feed F1 had the highest digestibility of 91.32 ± 0.07%, followed by feed F2, 82.25 ± 0.04%. The least digested feeds were Feed 4, (20% CPE) and feed 5, (25% CPE), 70.12 ± 0.06%and 70.23 ± 0.09% respectively. The fatty acids of CPE are dominated by saturated fatty acids (SFAs), which constitute about 49.9±0.08% of the total fatty acids. Among the SFAs hexadecanoic acid or palmitic acid, comprising 46.0 ±0.02% of the total fatty acid. Oleic acid, C18:1 accounts for 43.4 ±0.08%. The fatty acid of CSE is dominated by monounsaturated C18:1 linoleic acid. Oleic acid forms about 45.44±0.01% of the total lipid of sesame crude extract. Sesame extract also has 39.48±0.14 %, C18:2 polyunsaturated fatty acids linoleic acid. Catfish Fatty acids content resembles the fatty acid content of the feeds. The ∑SFA shows that catfish fed with feed F1 had the lowest somatic SFA of 48.58 %. The catfish fed feed 1 had more PUFA than the MUFA or SFA. Incorporation of sesame seed oil in the diets of C. gariepinus produces fish high in PUFA.