Vitamin deficiencies in rations of natural feedstuffs
A swine ration consisting of yellow corn, tankage, casein, linseed oil meal, alfalfa meal, vitamin A and D concentrate and mineral supplements, has been fed to rats from the time of weaning through maturity, including reproduction and lactation. Results indicate that for growth of weanling rats the ration under consideration is deficient in some combination of thiamine, riboflavin, pyridoxine and pantothenic acid. Using paired feeding trials it was shown that no one of these four vitamins is effective alone. Whether or not a simpler combination is effective is undetermined. After studying reproduction records it was apparent that the ration supported normal reproduction through parturition. However, at 28 days of age, only 16.5 to 63.0 per cent of the young were weaned, and average weaning weights were subnormal. Addition of choline to the basal increased the weaning percentage somewhat, but some unrecognized factor, present in liver, soluble in water and alcohol, and adsorbed on fuller's earth at pH 1, was effective in increasing the weaning percentage to normal. A crude concentrate of folic acid was also effective. Apparently the ration under consideration is not only deficient in these known growth factors, but also in an unrecognized factor (or factors) similar to, if not identical with, folic acid, and which is of special importance in suckling young. Apparently the deficiency is one affecting milk quality rather than quantity.