Chemical and quality evaluation of some alternative lipid sources for aqua feed production

A study was carried out on fish oil, two terrestrial animal fats (lard and chicken fat) and eight vegetable oils (palm kernel, sheabutter, soybean, palm, coconut, sunflower, groundnut and melon seed oils) to investigate their chemical and quality characteristics and the possibility of using them as alternative lipids in aquafeed. The results showed that the peroxide value of lard was significantly (P < 0.05) higher than values obtained in the other vegetable oils and animal fat sources; acid values of the oils ranged from 1.38 in coconut oil to 14.04 NaOH/g in palm kernel oil and were significantly different; the iodine value of sunflower oil, fish oil and soybean oil were comparable and higher, while a lower value that was not significantly different were observed in groundnut oil, coconut oil and melon seed oil. Thiobarbituric acid reactive substances of the oils were significantly different and showed low concentrations. The main fatty acids predominating in terms of relative abundance in the vegetable oils and animal fats examined are Lauric, palmitic, oleic and linoleic acids. Substantial levels of n-3 PUFA was observed in soybean oil and groundnut oil. The soybean oil and groundnut oil are exceptional high in the n-3 fatty acid content of the 18:3n-3 among the vegetable oils and would be a good lipid sources for tropical freshwater fishes.