The Effect of Cottonseed Products and Selected Feed Additives on Egg Yolk Discoloration

THE successful incorporation of cottonseed products in a layer ration has, for some time, been a problem for nutritionists as well as for poultrymen. Evidently, the first report of the problem was by Roberts and Rice (1891). They fed rations containing cottonseed meal which produced mottled yolks. However, no effort was made to determine the real cause of the abnormality. Similar results were indicated by Lamon and Lee (1917), who found that the “greenish spots on the yolks” were more frequent during the warmer portion of the year. Upon testing cottonseed meal produced from glanded and glandless cottonseed, Heywang et al. (1965) found that meal from glanded cottonseed produced a high incidence of mottled yolks while that from the glandless seed produced only limited mottling and in some cases no mottling. Thompson et al. (1930) found no evidence to show that gossypol was the factor involved in the discoloration of . . .