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Numerous practices in poultry husbandry are chiefly based on tradition and supposition. However, in consequence of the growing interest in poultry, many of the old traditional beliefs are being put to scientific test and those not supported by natural laws or scientific facts are being gradually abandoned. Since the fowl has no teeth with which to grind its feed, it is generally supposed that, to aid in reducing the feed to fineness in the gizzard, some hard, sharp material commonly termed “grit” must be supplied. This general belief, that grit is essential for chickens, appears to be about as firmly established as any that can be cited. In fact, in so far as the writers are aware, the literature reveals no instance of any one questioning the merits of the practice. Poultry writers of the past emphasized the importance of grit being sharp so as to cut or shred the . . .
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Bethke et al. (1926) studied this question.
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