پردیس کشاورزی و منابع طبیعی دانشگاه تهران Iranian Journal of animal Science 2008-4773 45 3 2014 09 23 Effect of different levels of dietary processed broiler litter on the performance of Holstein male cows Effect of different levels of dietary processed broiler litter on the performance of Holstein male cows 197 208 53775 10.22059/ijas.2014.53775 FA Ahmad Mohammadi M. Sc. Student, Department of Animal Science, Faculty of Agriculture, Tarbiat Modares University, Tehran Yousef Rouzbehan Associate Professor, Department of Animal Science, Faculty of Agriculture, Tarbiat Modares University, Tehran 0000-0001-6818-4465 Hasan Fazaeli Associate Professor, Department of Aniaml Science, Animal Science Research Institute, Karaj 0000-0002-2380-7611 Journal Article 2013 01 01 In a completely randomized design, the effect of four iso-protein and iso-caloric diets containing different levels (0, 8, 16 and 24%) of processed broiler litter was studied on the fattening performance of 60 Holstein male calves (with initial weight of 309±9kg and about 8-9 month age) for a period of 200 days. At the end of the experiment, all animals were slaughtered and then the carcasses, edible and non-edible parts were weighted after carcass inspection. Results showed that the average dry matter intake of calves fed diets containing four levels of poultry litter, were respectively 10.17, 10.28, 9.97 and 10.26 kg/d, daily weight gain were 1339, 1305, 1362 and 1311 g/d, and feed conversion ratio were 7.7, 7.9, 7.4 and 7.6 that were not affected by the experimental diets (P>0.05). In addition, the carcass weight, carcass dressing percentage and organs were not different among the treatments (P>0.05). Based on the visual tests, the carcasses and organs, no differences were observed between the animals received different levels of broiler litter.  Economically, feeding cost was lower when the animals received diets containing 16 and 24% of broiler litter. Based on the results of this experiment, the processed broiler litter could be included in the diet of finishing calves, however it is recommended that the optimum level to be about 20% on the farm conditions. In a completely randomized design, the effect of four iso-protein and iso-caloric diets containing different levels (0, 8, 16 and 24%) of processed broiler litter was studied on the fattening performance of 60 Holstein male calves (with initial weight of 309±9kg and about 8-9 month age) for a period of 200 days. At the end of the experiment, all animals were slaughtered and then the carcasses, edible and non-edible parts were weighted after carcass inspection. Results showed that the average dry matter intake of calves fed diets containing four levels of poultry litter, were respectively 10.17, 10.28, 9.97 and 10.26 kg/d, daily weight gain were 1339, 1305, 1362 and 1311 g/d, and feed conversion ratio were 7.7, 7.9, 7.4 and 7.6 that were not affected by the experimental diets (P>0.05). In addition, the carcass weight, carcass dressing percentage and organs were not different among the treatments (P>0.05). Based on the visual tests, the carcasses and organs, no differences were observed between the animals received different levels of broiler litter.  Economically, feeding cost was lower when the animals received diets containing 16 and 24% of broiler litter. Based on the results of this experiment, the processed broiler litter could be included in the diet of finishing calves, however it is recommended that the optimum level to be about 20% on the farm conditions. https://ijas.ut.ac.ir/article_53775_58bb56b4f4b027066cdca0dd1b8d8d35.pdf