Calcium and Phosphorus Requirements of Growing Yankasa Lambs in the Savanna Region of Nigeria

Abstract

Fifty-four Yankasa lambs of mixed sexes aged between 8-10 months were used in this experiment to determine the effect of varying levels of dietary calcium and phosphorus on the health, blood and bone characteristics. Three levels of dietary calcium (0.28 percent, 0.56 percent and 0.77 percent) and three levels of dietary phosphorus (0.31 percent, 0.40 percent and 0.60 percent) were tested in a 3 x 3 factorial arrangement. Blood samples were taken from the lambs at the beginning of the experiment and subsequently at two weekly intervals by jugular puncture. Measurements taken included the determination of calcium and phosphorus in the serum and humeri as well as the percentage ash, specific gravity and cortical indices of the humeri. Although serum calcium levels tended to be elevated at the high levels of calcium, differences among treatments were not statistically significant. Plasma calcium and phosphorus levels were normal in all groups throughout the experiment but significant differences were observed among groups for serum inorganic phosphorus. Significant differences existed among groups for specific gravity, percentage ash, calcium and phosphorus in dry fat-free bone with the high calcium high phosphorus diets (0.77 percent Ca, 0.60 percent P) giving consistently high values since indicators of nutritional status are markedly influenced by the age of the animal and the period of imposed deficiency. Growth performance is therefore a better index of the adequacy of dietary calcium and phosphorus in growing lambs above five months of age than serum calcium and phosphorus values. However, adequate mineralization of the bones requires the supplementation of the basal ration with calcium and phosphorus.