By-Products of the Refining of Soybean Oil as Pigment Sources for Poultry

LITTLE attention has been paid to fats as sources of xanthophylls for the pigmentation of chicks. Fritz (1962) stated that the role of added fat in this connection was controversial. Stable or stabilized fats tend to protect xanthophylls against oxidation and may improve their absorption. On the other hand, by raising the energy level of rations, fat supplements cause less feed to be eaten; thus, the birds will also consume less xanthophylls. On the whole, opinions are divided with respect to the effect of fat supplements (mainly tallow) on broiler pigmentation. Some authors (Fritz et al., 1957; Day and Williams, 1958; Elrod et al., 1958) have reported positive results, whereas others (Hammond and Harshaw, 1941; Ratcliff et al., 1959; Carver, 1959; Couch et al., 1963) denied the value of fat supplements in this respect or have obtained negative results. Papers dealing with the feeding of acidulated soapstocks to chicks have …