A deficiency seriously affects reproductive performance. Cows with a manganese deficiency do not show heat, have decreased conception rates, higher abortion rates and low birth weight calves. Calves are generally born weak and may be deformed with twisted legs and enlarged joints. Zinc Low zinc diets affect the testicular development of bulls and therefore can affect fertility in a herd. A zinc deficiency results in reduced sperm production and delays maturation of sperm.
Calves grow slowly and reach puberty at a later age than normal.
Zinc deficiency also results in reduced Vitamin A utilization and signs of a Vitamin A deficiency may be seen. In addition, high calcium and phosphorus levels decrease zinc absorption from the intestine. Iodine Cattle need iodine for the formation of two hormones that are produced by the thyroid gland. The thyroid gland is responsible for controlling the metabolic rate of the body. A lack of iodine indirectly influences growth rate, milk production and feed consumption.