Growth performance and carcass characteristics of feedlot cattle fed different levels of macadamia oil cake.

Eighteen cattle (six Bonsmara males, seven Simmanteler x Beefmaster males and five Simmanteler x Beefmaster females) were assigned to three diets containing 0% (Control), 10% and 20% Macadamia oil cake to evaluate the effects of different levels of Macadamia oilcake (MOC) on feed intake, growth performance and carcass characteristics of feedlot cattle. Differences in average feed intake were not significant (P > 0.05). Average daily gains on the 0% and 20% MOC diets were not significantly different (P < 0.05) but were significantly higher than the average gain on 10% MOC (P < 0.05). The inclusion of 20% MOC increased feed conversion ratio significantly (P < 0.05) compared with the other two treatments. The control group had significantly heavier warm carcasses than the 10% and 20% MOC groups and the 20% MOC group had significantly heavier carcasses than the 10% MOC group. The inclusion of MOC did not significantly affect the dressing percentage and conformation scores of the animals (P > 0.05). There were no condemned livers, suggesting that either there were no toxic factors in the feed or, even if present, were probably inactive in the liver.