Abstract:
Young cattle were fed whole or cracked wheat with 20% lucerne hay, either ad lib or at a medium level, restricted to approximately 2.3% of fasted liveweight. Over 70 days, animals fed ad lib consumed 3.2 and 2.7% of their mean fasted liveweight on whole and cracked wheat respectively, and weight gains on the ad lib diet were higher than those on the medium feeding level. Cracked wheat gave 32% higher liveweight gains than whole wheat when feeding was restricted to 2.3% of fasted liveweight. However, animals offered whole wheat ad lib consumed 24% more feed, and attained the same rate of gain as those on cracked wheat. Feed conversion ratios were 7.0 and 8.8 for cracked and whole wheat, respectively. It would be economical to crack wheat only if the cost of double handling and processing 6.6 t of wheat was less than the cost of an extra 2.0 t of whole wheat. Animals fed lupins for 42 days did not consume as much as those fed wheat, but gains were only slightly lower. Lupins may be better suited to increasing the protein content of mixed rations. Only when animals were fed ad lib was there some slight advantage in adding urea to wheat rations. When whole wheat and whole oats were fed at the same restricted level, liveweight gains were higher on oats and feed conversion ratio was lower.