Response time of broiler chickens to cimaterol: meat tenderness, muscle composition fiber size, and carcass characteristics.
The response time to cimaterol (CIM), a beta-adrenergic agonist, by broiler chickens for carcass characteristics, muscle composition, muscle fiber size, catheptic enzyme activity, and tenderness was determined. Two trials were conducted in which chickens were fed a control diet (CON) containing 0 ppm of CIM or a diet containing 1 ppm of CIM. Trial 1 consisted of 55, 31-d-old broiler chickens individually fed for up to 48 h. At 0, 6, 12, 18, 24, and 48 h, five CON and five CIM-fed chickens were killed. Trial 2 consisted of 160, 33-d-old broiler chickens group-fed for up to 14 d. At 2, 4, 6, 8, 10, 12, and 14 d, 10 CON and 10 CIM-fed chickens were killed. The breast muscle (BM) and leg muscle (LM) weight, cathepsin B and L activities, DNA, RNA, and protein concentration, and BM shear force value (SFV) were measured in both trials. Thigh muscle (TM) SFV were measured in Trial 2 only. Fiber size of BM was measured (five birds per treatment) at d 2, 6, 10, and 14. In Trial 1, BM weight and SFV were lower in CIM-fed birds at 6 h (P less than .05). In Trial 2 BM SFV were higher at d 8 (P = .06) and d 10 (P less than .05) in CIM-fed chickens. The SFV of CIM-fed chickens were higher at d 4, 8, 10, 12, and 14 (P less than .05).(ABSTRACT TRUNCATED AT 250 WORDS)
Gwartney
B L
BL
Department of Animal Science, University of Nebraska, Lincoln 68583-0908.
Jones
S J
SJ
Calkins
C R
CR
D000318:Adrenergic beta-Agonists / Q000494:pharmacology*; D000818:Animals; D002645:Chickens / Q000033:anatomy & histology / Q000254:growth & development*; D004247:DNA / Q000032:analysis; D004983:Ethanolamines / Q000494:pharmacology*; D008460:Meat / Q000592:standards*; D024510:Muscle Development; D009124:Muscle Proteins / Q000032:analysis; D009132:Muscles / Q000737:chemistry / Q000187:drug effects*; D012313:RNA / Q000032:analysis; D011897:Random Allocation
D000318:Adrenergic beta-Agonists; D004983:Ethanolamines; D009124:Muscle Proteins; D012313:RNA; D004247:DNA; C047411:cimaterol