This study was conducted at the Al-Bahaa Company farm, Elkhatatba, Menoufia governorate, and El-Rahep experimental station, Animal Production Department, Faculty of Agriculture, Menoufia University. The laboratory portion was conducted at the animal nutrition lab, Department of Animal Production, Faculty of Agriculture, Menoufia University (Shebin El-Kom), to investigate the effect of replacing yellow corn with citrus orange pulp at different levels in the diets of calves and sheep. The current study was carried out in two feeding trials; the first one was conducted to evaluate the effect of the replacement of yellow corn with orange pulp in three different levels, 15, 30 and 45%, on growth performance, blood biochemical, and immunity status of crossbreeding Barahama & Zibo calves (experiment 1). In order to clarify the results of the first experiment regarding the nutrient utilization as affected by dried orange pulp replacement level, it was thought that it would be better to re-design another digestion trial on sheep to determine the nutrient digestibility, nutritive values, nitrogen balance, and rumen fermentation (experiment 2). Four experimental rations (C, R15, R30, and R45) were prepared in TMR form with the same roughage: concentrate ratio of 30:70 % (70% CFM + 20% corn silage + 10% wheat straw) on a DM basis. Animals in two experiments received the same previous rations in four comparable groups.