title: The effects of a beta-agonist treatment, vitamin D3 supplementation and electrical stimulation on meat quality of feedlot steers.
abstract: In this study, 20 young steers received no beta-agonist (C), 100 animals all received zilpaterol hydrochloride (Z), with 1 group only receiving Z while the other 4 groups received zilpaterol and vitamin D3 at the following levels (IU/animal/day) and durations before slaughter: 7 million for 3 days (3D7M); 7 million for 6 days (6D7M); 7 million for 6 days with 7 days no supplementation (6D7M7N) and 1 million for 9 days (9D1M). Left carcass sides were electrically stimulated (ES) and the right side not stimulated (NES). Samples were aged for 3 or 14 days post mortem. Parameters included Warner-Bratzler shear force (WBSF), myofibril filament length, sarcomere length and calpastatin and calpain enzyme activity. Both ES and prolonged aging reduced WBSF (P<0.001). 6D7M, 6D7M7N and Z remained significantly tougher than C (P<0.001), while 3D7M and 9D1M improved WBSF under NES conditions. ES is more effective to alleviate beta-agonist induced toughness than high vitamin D3 supplements.
authors.affiliation: Agricultural Research Council, Private Bag X2, Irene, 0062, South Africa. pstrydom@arc.agric.za
authors.forename: P E
authors.initials: PE
authors.lastname: Strydom
authors.forename: M
authors.initials: M
authors.lastname: Hope-Jones
authors.forename: L
authors.initials: L
authors.lastname: Frylinck
authors.forename: E C
authors.initials: EC
authors.lastname: Webb
mesh_terms: D000821:Animal Feed; D000818:Animals; D002118:Calcium / Q000097:blood; D002135:Calcium-Binding Proteins / Q000378:metabolism; D002154:Calpain / Q000378:metabolism; D002417:Cattle; D002762:Cholecalciferol / Q000008:administration & dosage*; D019587:Dietary Supplements; D004558:Electric Stimulation; D008297:Male; D008460:Meat / Q000032:analysis*; D009210:Myofibrils / Q000378:metabolism; D010281:Parathyroid Hormone / Q000097:blood; D059748:Proteolysis / Q000187:drug effects; D012518:Sarcomeres / Q000378:metabolism; D014297:Trimethylsilyl Compounds / Q000008:administration & dosage*
chemical_list: D002135:Calcium-Binding Proteins; D010281:Parathyroid Hormone; D014297:Trimethylsilyl Compounds; C475840:Zilpaterol; D002762:Cholecalciferol; C033668:calpastatin; D002154:Calpain; D002118:Calcium