Field Studies on the Effect of Nicarbazin on Egg Quality

INTRODUCTION NICARBAZIN, a coccidiostat, was reported to cause several effects on egg quality. These are shell depigmentation (McClary, 1955; Ott et al., 1955, 1956a,b; Sherwood et al., 1956a), yolk mottling (Baker et al., 1956,1957; Polin and Porter, 1956; Polin et al., 1957; Weiss, 1957) and a decreased egg size (Sherwood et al., 1956b; Weiss, 1957; Baker et al., 1957). Shell depigmentation was reported to occur at a minimum effective level of 0.003 to 0.005 percent by Sherwood et al. (1956a) and Ott et al. (1957). Baker et al. (1957) reported the effect at 0.009 percent but not at the 0.003 percent level. Yolk mottling was reported in fresh eggs from Leghorns fed 0.0015 percent and a marked increase in the incidence at 0.003 percent in fresh eggs from both heavy and light breeds (Baker et al., 1957). This is contrary to the data reported by Polin (1957) who found that . . .