The two factors probably responsible for the inability to raise calves on a ration of whole milk alone are the development of rickets and anemia. Tetanic convulsions in calves probably arise in association with rickets. None of the calves in the experiments reported in this bulletin developed tetany as they were protected against rickets by feeding cod-liver oil and bone meal.
Blood pictures of the calves on a milk diet disclosed an anemic condition as measured by a reduced quantity of hemoglobin, a subnormal erythrocyte count and a lower specific gravity of the blood. The calves also became dyspneic, showed great weakness and lacked color around the tongue and muzzle. These conditions improved markedly upon feeding the roughages, alfalfa hay and straw. The blood also returned to normal.
Feeding of alfalfa hay and grain for a period before feeding a diet of whole milk allowed storage of iron in sufficient quantities to prolong the time of apparent good health. Blood pictures at the end of the trial were subnormal even tho the animal appeared vigorous.
When minimum amounts of milk were fed, supplemented with alfalfa flour, the calves retained the healthy appearance of hide and had no convulsions, which were displayed by calves in other experiments on a whole milk diet. The calves on the minimum milk-alfalfa flour diet were under-fed and many of them died of starvation.
Calves on milk diets grew faster in skeletal development than normal and when allowed optional amounts of milk were above normal in weight. Calves are capable of consuming adequate quantities of liquid whole milk to maintain normal or better than normal growth curves.
Cannon, C. Y.
"Supplements to a milk diet for dairy calves,"
Research Bulletin (Iowa Agriculture and Home Economics Experiment Station): Vol. 11
, Article 1.
Available at: https://lib.dr.iastate.edu/researchbulletin/vol11/iss136/1