The Effect of Dietary Soybean Oil on the Deposition of Xanthophyll in Broiler Skin

Many poultry processors face the difficulty of supplying uniformly pigmented birds to the market. The cost of adding pigment sources to the diet makes it necessary to obtain the maximum pigmentation and efficiency from the dietary source. Because much of this pigment is deposited in carcass lipid it was felt that if the amount of oil added to the diet varied, the total body lipid would also vary and the amount of pigment in and immediately underlying the skin would be altered and influence uniformity. Two trials were conducted to determine if varying dietary levels of oil would affect xanthophyll deposition in broiler skin. The birds in both trials were fed either 4, 7 or 10 percent oil in the diet which provided 2.17, 2.35 and 2.53 Cal. M.E./mg. of xanthophyll respectively. These rations were fed ad libitum from one day of age until they were sacrificed at 8 weeks of age for birds in trial 1 and 7 or 8 weeks of age for those in trial 2. Skin samples were taken from the breast and back of each bird, extracted with acetone and the xanthophyll content determined. The lipid from each sample was extracted with a chloroform-methanol mixture and weighed. The increase in dietary oil in the rations of this experiment did result in significant increases in xanthophyll deposition in the back skin for both 7 and 8 week old birds. More xanthophyll was deposited per gram of tissue as the percentage of dietary oil increased. The carcass weight and tissue lipid also increased as dietary oils were increased.