Effect of dietary calcium and zinc levels on weight gain and blood and tissue mineral concentrations of growing Columbia- and Suffolk-sired lambs.

One hundred and sixty Columbia- and Suffolk-cross intact male and female growing lambs (8 wk of age) were used in an 84-d feeding trial to determine the effect of two levels dietary Ca and Zn on weight gain, feed utilization and several blood and tissue traits. Two levels of Ca (.5 and .8%) and two levels of Zn (20 and 100 ppm) were fed in a 2 X 2 factorial arrangement of dietary treatments. There was no effect of diet on performance or on blood traits. Columbia lambs had heavier fleeces at slaughter than Suffolks (P less than .01) and males had heavier fleeces than females (P less than .01). Based on the similarity in performance among lambs fed the four diets differing in Ca and Zn level, it is concluded that a dietary Ca level of .5% and a Zn level of 19 to 26 ppm is adequate for normal weight gain, feed utilization, liver and humerus ash concentrations and blood plasma concentrations of Ca, P, Zn, total protein, albumin, alkaline phosphatase and blood hemoglobin and hematocrit. Further, it appears that an elevated level of dietary Ca does not precipitate a clinical Zn deficiency in the growing lamb, in contrast to the general observation in growing swine.