The use of corn and barley in diets for veal calves: Effects on performance, diet digestibility and carcass quality

Forty Holstein bull calves (73.6 +/- 6.3 kg) were used in a randomized comp lete block design to determine if varying the corn-to-barley ratio in the d iet affects growth, diet digestibility and carcass quality of grain-fed vea l calves. Five diets consisting of com:barley ratios of 100:0, 75:25, 50:50 , 25:75, 0:100 were offered along with a protein supplement (43.6% CP). Gra in-to-protein supplement ratios were 2:1, 3.5:1 and 5:1 for the starting, g rowing and finishing phases, resulting in diets of 23.5, 20.3, and 18.7% CP , respectively. Incidence of diarrhea increased with an increase in dietary barley (P < 0.05). Apparent digestibility of diets decreased as the propor tion of barley increased (P < 0.01). Throughout the experiment, DMI was the highest for diets containing 75% barley and the lowest for those containin g 100% corn (P < 0.01). Average daily gains behaved in a quadratic manner d uring the starting phase only (P < 0.01). This effect became linear during the growing and finishing phases, with ADG decreasing as dietary barley inc reased (P < 0.01). Average feed to gain ratio increased linearly with dieta ry barley content (P < 0.01). Hob carcass weights and yields decreased line arly with increasing proportions of barley (P < 0.01). Carcass color was no t affected by treatments. Carcass classification tended to decrease as diet ary barley increased. The results indicate that compared with barley, the u se of corn improves performance and diet digestibility of grain-fed veal.