Effects of feeds containing vegetable oils on the levels of omega-6 and omega-3 fatty acids present in farm-raised oreochromis niloticus (nile tilapia) Far Eastern University - Dr. Nicanor Reyes Medical Foundation / Section A.

Includes appendices and bibliographical references.

Abstract: Aquaculture, particularly Tilapia production, has become a growing industry that Filipinos are in to Oreochromis niloticus, commonly known as Nile Tilapia, is one of the considered aquaculturally important species of tilapia. This can be attributed to its adaptability to unfavorable environmental condition such as low oxygen and salinity, and its ability to utilize nutrients from different sources. However, fish feed technology is one of the under-developed sectors in aquaculture. This led to the development of several studies regarding the improvement of fish industry. In line with this tilapia, as one of the most abundant farm-raised freshwater fish, gained the attention of the researchers. Since tilapia cannot metabolize its own omega 6 & omega 3 fatty acids, its lipid content is derived mainly from its diet. It has been proven that lipid component of feeds, especially vegetable oil, increase the growth of the tilapia. In this study, the researchers sought to identify the effects of incorporating vegetable oil in feeds to the level of omega-6 and omega-3 fatty acids of tilapia. O. niloticus were collected from three top producers of Tilapia in the Philippines, namely Laguna, Nueva Ecija and Cavite. Components of the different feeds were noted from farm-raisers. It was identified that feeds from Laguna and Nueva Ecija contain vegetable oils (corn oil, soybean oil and coconut oil) while tilapia from Cavite has none. After the collection, the samples were filleted and skinned. Next, these were subjected to lipid extraction using Bligh and Dyer method. These were then brought to Industrial Technology Development Institute (ITDI), Department of Science and Technology (DOST) in Bicutan. The samples underwent conversion of lipids to Fatty Acid Methyl Esters (FAME), and Fatty Acid contents were quantified using Gas, chromatography. Nine fatty acids were identified in samples from Cavite and Nueva Eciya, while there were ten in Laguna. Based on the consolidated results, it was shown that tilapia given with feeds which contain vegetable oil has lower amounts of omega-3 fatty acid. The difference in the level of omega-6 fatty acids between the samples was insignificant. It was also found out that tilapia given with vegetable oil-containing feeds has a higher omega-6: omega-3 ratio (1:0.21), while tilapia were not given with vegetable oil-containing feeds has has a healthy ratio of 1: 1.15.

Thesis - Department of Biochemistry & Nutrition