title: Effect of a grazing period prior to finishing on a high concentrate diet on meat quality from bulls and steers.
abstract: Bulls and steers (n=60) were assigned to a pre-finishing grazing period and subsequently finished on concentrates or offered concentrates without grazing until slaughter (19months). Colour and pH of longissimus thoracis were measured (48h post-slaughter), and samples collected for proximate composition, collagen, sarcomere length, muscle fibre and enzymatic profile analysis. Steaks for texture, cook loss and sensory were aged (14days). Castration increased intramuscular fat content, cook loss and myosin isoforms IIa and I proportions, and decreased IIx proportion (P<0.05). Steer meat was positively correlated to overall tenderness, texture and acceptability (P<0.05). The presence of a pre-finishing grazing period decreased intramuscular fat and increased the proportion of IIa compared with animals on concentrates, while no differences were found in sensory. Muscle colour, collagen, sarcomere length and instrumental texture were not modified by diet or castration. In conclusion, beef sensory characteristics were unaffected by diet, whereas castration resulted in a small improvement; however all the treatments produced an acceptable product.
authors.affiliation: Teagasc, Food Research Centre, Ashtown, Dublin, 15, Ireland. Electronic address: Lara.Moran@teagasc.ie.
authors.forename: L
authors.initials: L
authors.lastname: Moran
authors.affiliation: University College Cork, School of Food and Nutritional Sciences, Cork, Ireland.
authors.forename: M G
authors.initials: MG
authors.lastname: O'Sullivan
authors.affiliation: University College Cork, School of Food and Nutritional Sciences, Cork, Ireland.
authors.forename: J P
authors.initials: JP
authors.lastname: Kerry
authors.affiliation: INRA & VetAgro Sup., Recherches sur les Herbivores, Theix, 63122 Saint-Genès-Champanelle, France.
authors.forename: B
authors.initials: B
authors.lastname: Picard
authors.affiliation: Teagasc, Animal & Grassland Research and Innovation Centre, Grange, Dunsany, Co.Meath, Ireland.
authors.forename: M
authors.initials: M
authors.lastname: McGee
authors.affiliation: Teagasc, Animal & Grassland Research and Innovation Centre, Grange, Dunsany, Co.Meath, Ireland.
authors.forename: E G
authors.initials: EG
authors.lastname: O'Riordan
authors.affiliation: Teagasc, Animal & Grassland Research and Innovation Centre, Grange, Dunsany, Co.Meath, Ireland.
authors.forename: A P
authors.initials: AP
authors.lastname: Moloney
mesh_terms: D000273:Adipose Tissue / Q000737:chemistry; D000821:Animal Feed / Q000032:analysis*; D000818:Animals; D001823:Body Composition; D002417:Cattle; D003116:Color; D003258:Consumer Behavior; D003296:Cooking; D004032:Diet / Q000662:veterinary*; D004041:Dietary Fats / Q000032:analysis; D004044:Dietary Proteins / Q000032:analysis; D063427:Food Quality; D060434:Herbivory; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D018485:Muscle Fibers, Skeletal / Q000737:chemistry; D009124:Muscle Proteins / Q000737:chemistry; D018482:Muscle, Skeletal / Q000737:chemistry; D009919:Orchiectomy; D000069466:Red Meat / Q000032:analysis*; D013649:Taste
chemical_list: D004041:Dietary Fats; D004044:Dietary Proteins; D009124:Muscle Proteins
keywords: Castration; Grazing period; Muscle fibre profile; Tenderness