Adaptation to Starch in Steers Fed by Nipple Pail

In a crossover design, four Holstein steers averaging eight months of age were fed liquid diets (20-25% solids) by nipple pail for two 8-wk periods.On a &T basis, diets contained 25.2% dried skimmilk, 7.2~ fish flour, 10% emulsified lard oil, and 57.6% corn starch or lactose.Between the fifth and seventh week of treatment, aqueous test meals containing 4.4 g carbohydrate per kg body weight of both lactose and starch were administered and blood sugar responses measured.Following the feeding periods, all calves were fed only the starch ration for 6 days while nutrient digestibilities were deternfined by total collection.Gains were significantly higher (P < .01) on lactose than starch (0.70 vs. 0.31 kg' day).Maxilnum increases in blood sugar following administration of the lactose averaged three times higher than for starch.Calves conditioned to lactose o'ave higher blood sugar responses (P < .10) to both the lactose and starch test meals than those conditioned to starch.Previous ration had no significant effect on digestibilities of starch or any other nutrient.Starch digestibilities for all steers averaged 60.19~.