Effects of Feeding Tallow and Plant Fat to Laying Hens on Performance, Egg Quality and Fatty Acid Composition of Egg Yolk

To determine the effects of sources of supplemental fat 200 Isa Brown layers were equally divided in 5 groups and assigned randomly to be fed ad libitum a standard commercial layer feed (BD), BD+ 4% tallow (T), BD+ mixture of 2% tallow and 2% flaxseed oil (MTFO), BD+ 4% sunflower oil (SO) and BD+ 4% flaxseed oil (FO) for 8 weeks. Dietary fat supplemantion affected the laying performance, but had no (P>0.05) effect on egg quality parameters. The supplemental tallow increased concentration of saturated fatty acids (palmitic: 29.10%, stearic:10.17%). The proportions of linoleic and arachidonic acids in egg yolks for layers fed the diet containing 4% sunflower oil were higher than other diets. The concentration of oleic acid (40.08%) was the highest in layers receiving 2% tallow + 2% flaxseed oil diet. In addition, dietary flaxseed oil increased the concentration of α-linolenic (4.15%) and DHA (2.54%) in yolk at the expense of other unsaturated fatty acids. It is concluded that dietary animal and plant fats can be used to modify composition of egg yolk.