Effects of Nicarbazin in Diet on Mottled Yolks: I. Incidence and Degree of Mottling, and Certain Yolk Proteins

Abstract

THE appearance of an abnormality in eggs, referred to as mottled yolks, has been recognized for many years, but little is known of its incidence in eggs from farm flocks. The mottled condition observed on egg yolks has been described as transparent, orange-yellow, oily appearing spots which appear on the surface of the yolks.Almquist (1933) observed mottled yolks in eggs from hens fed cottonseed meal in their diet. Yolks from newly-laid eggs appeared normal but the incidence and degree of mottling increased during storage. Since mottled yolks contained more water, more egg white protein and a higher protein-fat ratio than normal eggs, he concluded that mottled yolks were caused by diffusion of egg white protein into the yolk because the vitelline membrane was more permeable than that of normal eggs.Polin et al. (1956) reported the presence of mottled yolks in eggs from hens fed Nicarbazin3 (equimolecular complex of…