title: Biochemical and organoleptic characteristics of muscle from early and late maturing bulls in different production systems.
abstract: In grass-based beef production systems (PS), early maturing (EM) breed types may be preferable to late maturing (LM) breed types in achieving adequate carcass fat cover. Biochemical and organoleptic characteristics of muscle from suckler bulls were investigated in EM and LM (n=28/breed) assigned to one of two PS (ad libitum concentrates and grass silage to slaughter (C) or ad libitum silage plus 2 kg concentrate daily during winter followed by 99 days at pasture and then an indoor finishing period on C (GSPC)) in a 2 breed type×2 PS factorial arrangement of treatments. Bulls were managed to have a common target carcass weight of 380 kg. Intramuscular fat (IMF) content was higher (P<0.05) for EM than LM, and for C than GSPC bulls. Collagen solubility was higher (P<0.05) for C than GSPC bulls. Lactate dehydrogenase (LDH) and phosphofructokinase activities were higher (P<0.05) for LM than EM. Isocitrate dehydrogenase activity and the Type I myosin heavy chain (MyHC) proportion were higher (P<0.05) for EM than LM. The LDH activity and the Type IIX MyHC proportion were higher (P<0.05) for C than GSPC bulls. Sensory ratings for tenderness and juiciness were higher (P<0.01) for beef from EM than LM while sensory ratings for tenderness, flavour liking and overall liking were higher (P<0.001) for C than for GSPC bulls. Differences in sensory quality were largely eliminated when adjusted for IMF. Overall, carcass fat scores, IMF and sensory scores were higher in EM than LM and in C than GSPC bulls but most differences in sensory quality could be attributed to differences in IMF.
authors.affiliation: 1School of Agriculture and Food Science,University College Dublin,Dublin 4,Ireland.
authors.forename: G B
authors.initials: GB
authors.lastname: Mezgebo
authors.affiliation: 1School of Agriculture and Food Science,University College Dublin,Dublin 4,Ireland.
authors.forename: F J
authors.initials: FJ
authors.lastname: Monahan
authors.affiliation: 2Animal and Grassland Research and Innovation Centre,Teagasc,Grange,Dunsany,County Meath,Ireland.
authors.forename: M
authors.initials: M
authors.lastname: McGee
authors.affiliation: 2Animal and Grassland Research and Innovation Centre,Teagasc,Grange,Dunsany,County Meath,Ireland.
authors.forename: E G
authors.initials: EG
authors.lastname: O'Riordan
authors.affiliation: 3UMR1213 Herbivores,INRA, VetAgro Sup, Clermont Université,Université de Lyon,F-63122 Saint-Genès-Champanelle,France.
authors.forename: B
authors.initials: B
authors.lastname: Picard
authors.affiliation: 4School of Veterinary Science, Faculty of Health Sciences,University of Bristol,Langford,Bristol BS40 5DU,UK.
authors.forename: R I
authors.initials: RI
authors.lastname: Richardson
authors.affiliation: 2Animal and Grassland Research and Innovation Centre,Teagasc,Grange,Dunsany,County Meath,Ireland.
authors.forename: A P
authors.initials: AP
authors.lastname: Moloney
mesh_terms: D000273:Adipose Tissue / Q000378:metabolism; D000818:Animals; D002417:Cattle / Q000502:physiology*; D004032:Diet / Q000662:veterinary; D007521:Isocitrate Dehydrogenase / Q000378:metabolism; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008297:Male; D018482:Muscle, Skeletal / Q000201:enzymology / Q000502:physiology*; D018995:Myosin Heavy Chains / Q000378:metabolism; D025221:Phosphofructokinases / Q000378:metabolism; D006109:Poaceae; D000069466:Red Meat / Q000592:standards*; D012677:Sensation; D012820:Silage; D013649:Taste
chemical_list: D007770:L-Lactate Dehydrogenase; D007521:Isocitrate Dehydrogenase; D025221:Phosphofructokinases; D018995:Myosin Heavy Chains
keywords: beef; breed type; diet; intramuscular fat; sensory