%0 Journal Article %T Effect of Zinc, Copper and Chlortetracycline Supplementation on Fat Thickness and Longissimus muscle in Young Holstein Bulls %J Iranian Journal of animal Science %I پردیس کشاورزی و منابع طبیعی دانشگاه تهران %Z 2008-4773 %A Fagari Nobijari, Hadi %A Amanlou, Hamid %A Dehghan Banadaki, Mehdi %A Hoseini Sabeghi, Seyed Hosein %A Ghazvinian, Khosro %D 2010 %\ 05/22/2010 %V 41 %N 1 %P - %! Effect of Zinc, Copper and Chlortetracycline Supplementation on Fat Thickness and Longissimus muscle in Young Holstein Bulls %K Blood metabolites %K Copper %K Fat thickness %K Longissimus muscle %K Young bulls %R %X Three hundred eighteen young Holstein bulls (initial BW = 375 ± 17.5 kg) were randomly allotted to one of six treatments in a completely randomized design for 56 d the treatments of which consisted of 1) the basal diet (control); 2) basal diet plus 30 mg of Cu/kg of DM as CuSO4; 3) basal diet plus 150 mg of Zn/kg of DM as ZnSO4; 4) basal diet plus chlortetracycline (200 mg/animal/d; CTC); 5) basal diet + Cu + CTC; and 6) basal diet + Zn + CTC within the same dose. Effects of treatments on blood metabolites and Back fat thickness, Rump fat thickness, Longissimus muscle area and Hip height were evaluated. Serum urea nitrogen (P < 0.001) and plasma total protein (P < 0.001) were different among treatments. Copper supplementation improved ultrasound index, however, zinc supplementation negatively affected (P < 0.001). As a result, the control of Cu and Zn levels, as replacers for CTC, in the diet of young bulls can increase Longissimus muscle area and can decrease fat thickness. %U https://ijas.ut.ac.ir/article_21019_178c143bf6b4e12f1a4a52ed0223e585.pdf