Grit for Laying Hens

AMPLE experimental evidence is available to indicate a need for grit when poultry are fed whole grains (Heuser and Norris, 1946; Scott and Heuser, 1957; Balloun and Phillips, 1956; and Combs et al., 1954). The value of grit when all-mash rations are fed is somewhat controversial. However, several workers have reported data which indicate that grit is beneficial when all-mash rations are fed to starting, growing and adult birds. Bird et al. (1937) found that chicks fed a finely ground grit-free ration developed an abnormal thickening of the gizzard lining which could be prevented by feeding grit or a coarsely ground feed. Heuser and Norris (1946) noted that the addition of grit to a practical type starter did not materially influence chick weight, but there appeared to be some improvement in feed efficiency. Bell and Simpson (1949) reported an increase in growth rate and feed efficiency as a result of . . .