The possiblity of saving imported soybean meal contained in calf starter rations by replacing it with urea or groundnut meal was examined in the Experiment 1 and 2.
　Experiment 1: Eight calves were divided into two groups D and E, to which calf stater rations R-D and R-E were supplied respectively, during the Periods I and II. Then the both groups were fed R-F. All calves were fed whole milk until 10 weeks of age, and were fed green Napier grass from the first to the end of the experiment. The R-D contained 20% of soybean, while the R-E contained only 5% of soybean meal and 1% of urea. The R-F contained 1% urea and increased amount of leaf meal and brewer's grain, but not soybean meal. The percentages of TDN and DCP for R-D, R-E and R-F were 75.5%, 19.5%, 75.6%, 19.3% and 70.4%, 16.3%, respectively.
　Groups D and E gained 39.4 kg and 39.0 kg of body weight with 0.438 kg and 0.434 kg of daily gain, respectively during the whole experimental period.
　Digestivilities, TDN and DCP contents of R-D and R-E did not show statistically significant differences but R-F was lower in digestibility, TDN and DCP contents than R-D and R-E.
　Groups D and E could not consume sufficient amount of TDN at the later stage of experiment. However, both groups could get sufficient amount of DCP compared with the TDN and DCP requirements for 0.3 kg of daily gain. The calf starter ration which contained 1% of urea in addition to 5% soybean meal and other protein feed materials gave the similar growth rate to the control diet containing 20% of soybean meal as a main protein source and the other protein feed materials.
　Experiment 2: The possibility of replacing soybean meal with groundnut meal or less amount of groundnut meal plus urea in calf starter ration was investigated.
　Twelve calves were divided into three groups G, H and I. They were fed calf starter rations R-G, R-H and R-I, respectively, in pre- and post-weaning period. The percentages of TDN and DCP for R-G, R-H and R-I were 75.5%, 19.5%, 76.8%, 19.1% and 75.2%, 18.3%, respectively.
　Average daily gains for Groups G, H and I in the whole experimental period were 0.458 kg, 0.453 kg and 0.381 kg, respectively. Group I shows a lower daily gain than other groups, but the difference was not significant.
　Digestibility and TDN, DCP and DE contents of R-H were slightly lower than those of R-G and R-I, but statistically significant differences were not recognized among the three diets.
　All the calves of three groups could not take sufficient amount of TDN at the first 7 weeks of age and later 13 to 14 weeks of age. They were also unable to consume sufficient amount of DCP till 4 weeks of age.
　Calves receiving diets with 20% of groundnut meal or 10% of groundnut meal plus 1% of urea as a substitute for soybean meal could attain almost the same growth rate as those fed control diet containing 20% of soybean meal. Due to the presence of Aflatoxin in groundnut meal, the amount of this ingredient in calf starter rations must always be within the safe level, for the avoidance of causing any ill effect to calves