ABSTRACT:
Weaned bison bull calves (n=78; avg wt. 471 +/- 18 pounds) were randomly assigned to four different feedlot diets in a 4 treatment by 4 period Latin square study. The feeding periods were 80 days long and closely associated with spring, summer, fall and winter seasons. The four dietary treatments were identified based on major ingredients in the formulation and are described as (1) wheat screenings, (2) wheat middlings, (3) crambe meal and (4) a commercial bison ration. A significant season effect (P<0.10) was observed for gain with winter gains lower (P<0.01) than spring, summer and fall. Gains averaged 1.73 lbs. during the spring, 1.38 lbs. during the summer, 1.76 lbs. during the fall, and 0.38 lbs. during the winter. Average daily gains were 1.73 lbs. for wheat screenings, 1.63 lbs. for wheat middlings, 1.53 lbs. for crambe meal, and 1.61 lbs. for the commercial diet during the 242 days of spring, summer and fall seasons. Wheat screenings gains were higher (P=0.07) than crambe meal with wheat midds and the commercial diet intermediate. No differences were detected due to dietary treatment for dry matter intake, intake per unit weight, and dry matter per gain. Feed costs per pound of gain were $.54 for wheat screenings, $.73 for wheat middlings, $.73 for crambe meal, and $.89 for the commercial diet. Bison in this study gained less in the winter than other seasons, consumed a variety of feeds with limited differences in performance that resulted in highly variable feed cost per pound of gain.
