Faculty of Agrobiotechnical Sciences Osijek and Agricultural Institute Osijek
Abstract
The research on effects of different oils on the profile of fatty acids in egg yolks was performed on 80 ISA Brown laying hens (40 in control and 40 in experimental group). Hens were 50 weeks old. The control group of hens was fed diets supplemented with sunflower oil (6%), and the experimental group was given a combination of rapeseed oil (4%) and fish oil (2%). Hens’ diets contained 16.8% of crude protein and 11.57 MJ ME. The research lasted for 28 days. Content of fatty acids in yolk lipids was determined on 10 samples taken from each group. Supplemented oils (sunflower, rapeseed and fish oil) in hens’ diets had significant effect on the profile of fatty acids in yolk lipids. Compared to the control group, yolk lipids of eggs produced by hens in the experimental group contained significantly higher (P<0.001) portion of favorable fatty acids (linolenic, C18:3n-3; eicosapentaenoic, C20:5n-3 and docosahexaenoic, C22:6n-3). Moreover, the experimental group of hens laid eggs that contained less unfavorable saturated fatty acids (P<0.001) and less linoleic (C18:2n-6) and arachidonic acid (C20:4n-6) in their lipids. Content of oleic acid (C18:1) and total monounsaturated fatty acids (MUFA) was significantly higher (P<0.001) in yolk lipids of the experimental group. The experimental group contained less unfavorable polyunsaturated fatty acids of the n-6 type (n-6 PUFA, P<0.001), more favorable fatty acids of the n-3 type (n-3 PUFA, P<0.001) and more favorable n-6 / n-3 PUFA ratio (P<0.001) in yolk lipids than the control group.Istraživanje utjecaja različitih ulja na profil masnih kiselina u žumanjcima jaja obavljeno je na 80 ISA Brown nesilica (40 u kontrolnoj i 40 u pokusnoj skupini) starih 50 tjedana. Kontrolna skupina nesilica dobivala je u hrani suncokretovo ulje (6%), a pokusna skupina kombinaciju repičinog (4%) i ribljeg (2%) ulja. Smjese za nesilice sadržavale su 16,8% sirovih bjelančevina i 11,57 MJ ME. Istraživanje je trajalo 28 dana. Sadržaj masnih kiselina u mastima žumanjka određen je na 10 uzoraka iz svake skupine. Korištena ulja (suncokretovo, repičino i riblje) u hrani za nesilice imala su značajan utjecaj na profil masnih kiselina u mastima žumanjaka jaja. U mastima žumanjaka kod pokusne skupine nesilica utvrđen je značajno veći (P<0,001) sadržaj poželjnih masnih kiselina (linolenske, C18:3n-3; eikozapentaenske, C20:5n-3 i dokozaheksaenske, C22:6n-3) u odnosu na kontrolnu skupinu. Osim toga, pokusna skupina nesilica imala je manji sadržaj (P<0,001) nepoželjnih zasićenih masnih kiselina te linolne (C18:2n-6) i arahidonske kiseline (C20:4n-6) u mastima žumanjaka. Sadržaj oleinske kiseline (C18:1) i ukupnih mononezasićenih masnih kiselina (MUFA) bio je značajno veći (P<0,001) u mastima žumanjaka pokusne skupine. Pokusna skupina nesilica imala je manji sadržaj nepoželjnih polinezasićenih masnih kiselina n-6 tipa (n-6 PUFA, P<0,001), veći sadržaj poželjnih masnih kiselina n-3 tipa (n-3 PUFA, P<0,001) i povoljniji omjer n-6 / n-3 PUFA (P<0,001) u mastima žumanjaka jaja odnosu na kontrolnu skupinu
