Grit Feeding Affects Growth and Feed Utilization of Chicks and Egg Production of Laying Hens

IT IS commonly acknowledged that it is desirable to include some type of hard grit in the diet of chickens for optimum feed utilization and health. Bird et al. (1937) found that chicks raised on a finely ground, gritless ration developed an abnormal thickening of the gizzard lining and that this condition was prevented by feeding grit or a coarsely ground feed. Heuser and Norris (1946b) noted that the addition of granite grit to a practical type starting mash did not materially influence chick weight, but there seemed to be some improvement in feed efficiency. Bell and Simpson (1949) reported that grit-fed broilers weighed more and consumed less feed during a 9-week experimental period than did control birds without grit. Maclntyre and Jenkins (1952) reported no differences in egg production, feed consumption or maintenance of body weight between hens fed grit and those not receiving grit. In their experiments, the…