Further Comments on the Effect of Nicarbazin on the Egg

THE spectacular “bleaching” action of Nicarbazin on brown-shelled eggs (Ott et al., 1955; McLary, 1955) has undoubtedly led to consideration of the use of this drug for control of shell color where this factor is of marketing importance (Sherwood et al., 1956a). But reports of undesirable effects of Nicarbazin on production, egg weight, and yolk mottling (Baker et al., 1956; Ott et al., 1956; Polin et al., 1956; Polin and Porter, 1956; and Sherwood et al., 1956b) indicate that its use on laying flocks would be severely limited. On the other hand, these same papers carry the suggestion that the severity of the effect on the egg may vary considerably from one group of birds to another. The present report extends observations on the bleaching action to birds laying the sometimes hard-to-market “tinted” egg and shows that undesirable effects vary considerably among groups of birds. PROCEDURE Standard laying ration containing . . .