Growth Studies with Calves and Rabbits Fed Timothy Hay Grown on Heavily Fertilized Soils ,

Abstract

Summary This experiment was conducted to identify nutritional deficiencies in timothy hay grown on a heavily fertilized soil. When this hay was fed to calves with a concentrate mixture of degermed corn meal, nonfat dry milk solids or urea, vitamins A and D, cobalt, calcium, phosphorus, and common salt, the ration was deficient in iron, copper, and iodine, resulting in poor growth, poor appetite, anemia, and enlarged thyroids. Feeding iron and copper, either individually or in combination, did not correct these symptoms. Iodine supplementation corrected the thyroid condition but did not stimulate growth. When similar hay was fed to rabbits in a ration supplemented with wheat gluten, hydrogenated vegetable oil, dextrose, sodium chloride, and vitamins A and D, it also resulted in poor growth, anemia, and increased thyroid weight. Feeding of a ration containing 5% alfalfa prevented all these symptoms, but an equivalent amount of alfalfa ash or iodine prevented only the enlarged thyroid. The timothy hay apparently was deficient in iodine and some organic factor(s) which may be found in alfalfa hay.