Sunflower cake mixed with crude glycerine in the diet of Semi-heavy laying hensThe use of alternative feeds in the diet of laying hens can reduce costs and add nutritional value to the eggs; however, information on the combined effects of sunflower cake and crude glycerine remains limited. This study evaluated the individual and combined effects of including both ingredients on productive performance, egg quality and the oxidative stability of egg yolks from semi-heavylaying hens, based on the hypothesis that moderate levels do not compromise performance and may improve the antioxidant quality of the eggs. A total of 320 Hy-Line Brown laying hens were used in a completely randomised design, employing a 4 x 2 factorial scheme with five replications, each of eight hens. Four levels of sunflower cake and two levels of crude glycerine were evaluated. The data were submitted to analysis of variance, with the mean values compared using the SNK test (5%) and the levels of sunflower cake evaluated by regression analysis. The addition of 27% sunflower cake reduced egg mass and production, had an adverse effect on feed conversion, the specific gravity of the eggs and yolk colour, while increasing the levels of phenolic compounds and antioxidant capacity, and reducing lipid oxidation in the yolk. Glycerine had no effect on productive performance, but reduced specific gravity, increased the occurrence of shell blemishes and increased lipid oxidation in the yolk. Regardless of the use of glycerine, the addition of up to 18% sunflower cake is viable, increasing antioxidant capacity and reducing lipid oxidation in fresh eggs and eggs stored for up to 28 days.
Keywords:
Alternative feeds; Antioxidant activity; Anti-nutritional factors; Lipid oxidation.