Semi-Purified Diets for Sheep

Abstract

Six experiments involving a total of 75 growing-fattening lambs were conducted to evaluate semi-purified diets in terms of growth, feed efficiency and general appearance. The semi-purified diets tested compared most favorably with Pudue “58” lamb pellets in promoting a good rate of growth of lambs. Average daily gains of the lambs fed semi-purified diets ranged from 0.40 to 0.54 lb. An average daily gain of 0.54 lb. was obtained with the Purdue “58” pellet. The addition of 3% (instead of 1%) corn oil to the semi-purified diet greatly reduced the dustiness of the feed and thus improved palatability and feed intake. Celluflour was shown to be highly unsuited as a source of roughage in semi-purified diets. On the other hand, finely ground corn cobs included in the diet at either 10 or 20% level would seem to have a highly beneficial role, where feasible, in semi-purified diets. The addition of B vitamins to the semi-purified diet significantly improved the growth rate of the lambs. Increasing the dietary level of zinc from 10 to 60 ppm appeared to improve the growth rate of the lambs. However, there was a highly significant interaction between 60 ppm zinc and added B vitamins. The interaction resulted in a slower rate of gain when both B vitamins and zinc were added to the diet than when the diet was supplemented with either B vitamins or zinc alone.