The Restriction of Ooporphyrin Deposition on Egg Shells by Drug Feeding

The development, through research, of new growth stimulants and drugs for disease and parasite preventives and treatments in poultry might be expected to result in some “accidental” discoveries of fundamental value in research. One such discovery has resulted from the use of a new coccidiostat recommended for chickens under 12 weeks of age. The drug which is known by the trade name Nicarbazin (Merck) has the formula 4,4′ dinitrocarbanilide, 2 hydroxy-4,6-dimethylpyrimidine. Some indication of peculiar results of feeding this drug to certain breeds of laying hens prompted the work herein reported. In a preliminary test on the effect of nicarbazin on egg shell color, three White Rock hens were selected and initial individual egg shell color established. They were then moved to a small pen and changed from the conventional breeder ration to a ration containing .0125 percent nicarbazin. The hens were trapnested daily for seven days and the eggs …