High-starch, coarse-grain, low-fiber diets maximize growth of weaned dairy calves less than 4 months of age

Starch concentration, fiber concentration and type, and diet form were evaluated using Holstein steer calves from 2 to 4 mo of age in four 56-d trials. In trial 1, 96 calves were fed a high-starch diet that had the same composition in meal, pelleted, and whole-grain textured forms that was blended with 5% chopped grass hay at the time of feeding. In trial 2, the same meal and textured diets were retested with 96 calves. Calves fed the meal form diet consumed less DM and had lower ADG than the calves fed the textured form diet in each trial (P < 0.05). In trial 3, 96 calves were fed either a high-starch, whole-grain textured or low-starch, high-fiber (wheat middlings, soyhulls, distillers grains) pelleted diet that was blended with either 4 or 12% chopped alfalfa-grass hay. Calves fed the high-starch, low-hay diet had greater (P < 0.05) ADG, intake, feed efficiency, and change in BCS than calves fed the other treatments. In trial 4, 48 calves were fed a high-starch, whole-grain textured or 0, 20, 40, and 60% of a low-starch, pelleted diet blended with the high-starch, textured diet for progressive 14-d intervals. There were no differences in calf performance. Coarse high-starch textured diets supported more intake and ADG than meal form diets. Fiber from fibrous concentrates and roughages reduced calf performance and need to be introduced slowly in moderate amounts to calves under 4 mo of age.