Effects of dietary oil sources on egg quality, fatty acid composition of eggs and blood lipids in laying quail
This study was performed to investigate the effects of different oils in the diets of laying quail on their performance, egg quality, serum lipids and fatty acid composition of egg yolk. One hundred and ninety two 12-wk old Japanese quail were allocated to eight groups with two replicates containing 12 quail each. They were fed for 10 weeks on diets containing 4% oil from different sources, viz. either sunflower, sesame, cottonseed, olive, hazelnut, maize, soyabean or fish oil. The dietary oils affected egg weight and its specific gravity, the egg yolk index and the Haugh unit but had no effect on live weight of the birds, eggshell thickness and albumen index. The highest egg weights were recorded in the groups fed olive and sunflower oil. Eggs from the soyabean oil group had the highest specific gravity. Serum triglyceride concentrations were lower in the birds receiving diets containing sunflower and hazelnut oil than in the other treatments. Serum total cholesterol levels were higher in the groups fed hazelnut and cottonseed oil than in those receiving the other oils. Serum low density lipoprotein (LDL) levels were lower in the groups fed soyabean and olive oil than the other oil sources. The results of this study demonstrated that olive oil improved egg weight and egg shell quality compared to the other oils tested; fish and soyabean oil increased the omega-3 fatty acid level of egg yolk, and soyabean oil had positive effects on serum lipid concentrations. Incorporation of these oils into the diets of Japanese quail may have practical value in manipulating egg yolk quality.
Keywords: Blood lipids, egg, fatty acid, oils, performance, Japanese quail
South African Journal of Animal Science Vol. 38 (2) 2008: pp. 91-100