NUMEROUS instances have been recorded in New Zealand in which domestic animals have failed to grow or to produce to their full capacity through the entire lack of or the reduction to a low level of some of the essential food factors required by the body. Deficiencies of iodine and phosphorus undoubtedly exist as such, while cobalt. and iron deficiencies are as yet interrelated. Calcium and magnesium deficiencies may or may not .exist, while -protein deficiency is also to be considered only as a

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... possibility. Vitamin deficiencies, particularly A and D, may exist in intensively fed stock such as pigs and poultry, but except in pigs are to-day relatively unimportant in New Zealand live-stock feeding