Combined effects of clenbuterol and various concentrations of protein on performance of broiler chickens.
1. The effects of the beta-adrenergic agonist, clenbuterol (1 mg/kg diet) on the growth and muscle composition in female broiler chickens (14 to 32 d of age) fed on diets containing various concentrations of protein (220, 240 or 260 g protein/kg) were examined. 2. Body weight gain over the 18 d period increased linearly with increasing protein intake. The rate of gain was significantly higher in clenbuterol-treated chickens than in control birds. 3. Dietary clenbuterol increased thigh muscle weight and protein concentration of breast and thigh muscle, regardless of dietary protein content. Protein/DNA ratio in thigh muscle was enhanced by clenbuterol feeding, and the magnitude of difference of the ratio was higher in chickens fed on the 240 and 260 g CP/kg diets than in those fed the 220 g CP/kg diet. 4. It was concluded that clenbuterol-treated chickens require increased dietary protein to maintain maximal growth, and that increased protein consumption is an important factor in improving growth in clenbuterol-fed broilers.
Hamano
Y
Y
Department of Animal Science, Kitasato University, Towada-shi, Japan. yhamano@ampm.apca.ac.jp
Kume
K
K
Yamazaki
S
S
Kobayashi
S
S
Terashima
Y
Y
D000273:Adipose Tissue / Q000033:anatomy & histology; D000318:Adrenergic beta-Agonists / Q000494:pharmacology*; D000704:Analysis of Variance; D000821:Animal Feed; D000818:Animals; D001823:Body Composition / Q000187:drug effects*; D002645:Chickens / Q000254:growth & development*; D002976:Clenbuterol / Q000494:pharmacology*; D002149:Energy Intake / Q000187:drug effects; D004734:Energy Metabolism / Q000187:drug effects; D005260:Female; D005527:Food, Fortified; D008460:Meat; D018482:Muscle, Skeletal / Q000033:anatomy & histology; D009929:Organ Size / Q000187:drug effects; D012044:Regression Analysis; D013997:Time Factors; D015430:Weight Gain / Q000187:drug effects*
D000318:Adrenergic beta-Agonists; D002976:Clenbuterol