The use of corn and barley in diets for veal calves: Effects on performance, diet digestibility and carcass quality. Can. J. Anim. Sci. 78: [351][352][353][354][355][356][357][358]. Forty Holstein bull calves (73.6 ± 6.3 kg) were used in a randomized complete block design to determine if varying the corn-to-barley ratio in the diet affects growth, diet digestibility and carcass quality of grain-fed veal calves. Five diets consisting of corn:barley ratios of 100:0, 75:25, 50:50, 25:75, 0:100 were offered along with a protein supplement (43.6% CP). Grain-to-protein supplement ratios were 2:1, 3.5:1 and 5:1 for the starting, growing 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 proportion of barley increased (P < 0.01). Throughout the experiment, DMI was the highest for diets containing 75% barley and the lowest for those containing 100% corn (P < 0.01). Average daily gains behaved in a quadratic manner during the starting phase only (P < 0.01). This effect became linear during the growing and finishing phases, with ADG decreasing as dietary barley increased (P < 0.01). Average feed to gain ratio increased linearly with dietary barley content (P < 0.01). Hot carcass weights and yields decreased linearly with increasing proportions of barley (P < 0.01). Carcass color was not affected by treatments. Carcass classification tended to decrease as dietary barley increased. The results indicate that compared with barley, the use of corn improves performance and diet digestibility of grain-fed veal.Key words: Veal calves, corn, barley, starch digestion, carcass quality Noon, C. D., Seoane, J. R. et Scott, S. L. 1998. L'utilisation du maïs et de l'orge dans les rations des veaux de grain: effets sur la croissance, la digestibilité des rations et la qualité des carcasses. Can. J. Anim. Sci. 78: 351-358. Quarante veaux mâles Holstein (73,6 ± 6,3 kg) ont été utilisés dans un dispositif en blocs aléatoires afin de déterminer si différents rapports maïs:orge dans la ration affectent la croissance, la digestibilité des rations et la qualité des carcasses. Les traitements consistaient de cinq rapports maïs:orge (100:0, 75:25, 50:50, 25:75, 0:100) offerts avec un supplément protéique (43,6% PB). Les rapports grain:supplé-ment étaient de 2:1, 3,5:1 et 5:1 pour les rations de démarrage, de croissance et de finition, ce qui donnait des rations contenant 23,5%, 20,3%, and 18,7% PB, respectivement. L'ajout de l'orge aux rations a augmenté l'incidence des diarrhées (P < 0,05). La digestibilité apparente des rations diminuait lorsque la proportion d'orge augmentait (P < 0,01). Pendant la durée de l'expérience, l'ingestion de la MS était la plus élevée pour les rations contenant 75% d'orge et la moins élevée pour celles contenant 100 % de maïs (P < 0,01). Le gain moyen quotidien (GMQ) montrait un effet quadratique durant la phase de démarrage (P < 0,01). Cet effet est devenu l...