To evaluate the effect of different levels of Dried Citrus Pulp (DCP) and urea on performance of fattening male calves, twenty Brown Swiss male calves (192.15±30 kg live weight and 196.3±24 days age) were housed in individual tie stalls and randomly allocated to four experimental diets as follows: without urea and DCP (control), 12% DCP+0% urea, 0% DCP+0.65% urea and 12% DCP+0.65% urea. The experimental diets consisted of 35% forage (corn silage) and 65% concentrate. The length of the trail was 100 days (15 days for adaptation and 85 days for experimental period). Data showed that experimental diets had significant effect on nutrients apparent digestibility (p<0.05). The dry matter and crude protein digestibility of diet four was higher than other diets. According to the results, the experimental diets had no significant effect on dry matter intake, average daily gain and feed to gain ratio (p>0.05). There was no significant difference in rumen pH but rumen N-NH3 was significantly differ between treatments (p<0.05). Calves were fed diet three significantly had the highest rumen N-NH3. Ruminating, eating and chewing of calves had no significant difference between treatments (p>0.05). Blood metabolites (glucose, triglyceride, urea nitrogen) were not significantly affected by experimental diets approximately 2 h after feeding. The experimental diets had no significant effect on carcass and liver weight (p>0.05). It seems that including of dried citrus pulp supplemented urea in the fattening male calves ration can improve dry matter intake, feed conversion ratio, average daily gain and increase nutrients apparent digestibility of Brown Swiss male calves

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