Mezgebo G B, Moloney A P, O'Riordan E G, McGee M, Richardson R I, Monahan F J
1School of Agriculture and Food Science,University College Dublin,Dublin 4,Ireland.
2Teagasc,Animal and Grassland Research and Innovation Centre,Grange,Dunsany,County Meath C15PW93,Ireland.
Animal. 2017 Mar;11(3):538-546. doi: 10.1017/S1751731116001944. Epub 2016 Oct 3.
Bull beef production is traditionally based on high concentrate rations fed indoors. Inclusion of grazed grass, which is generally a cheaper feed, would decrease the cost of bull beef production, but may affect beef quality. Accordingly, the organoleptic quality and composition of beef from continental-sired suckler bulls (n=126) assigned to either ad libitum concentrates to slaughter (C), grass silage (GS) ad libitum for 120 days followed by C (GSC) or GS followed by 100 days at pasture and then C (GSPC) and slaughtered at target carcass weights (CW) of 360, 410 or 460 kg was examined. Tenderness, flavour liking and overall liking were lower (P<0.05) for GSPC than for C and GSC. Intramuscular fat content and soluble collagen proportion were lower (P<0.05) for GSPC than GSC which was lower (P<0.05) than C. Soluble collagen proportion was lower (P<0.05) for 460 kg than 410 kg CW, which was lower (P<0.05) than 360 kg CW. Inclusion of a grazing period decreased the ratings of tenderness, flavour liking and overall liking, but age of the bulls at slaughter had no clear influence on sensory characteristics.
传统上，育肥牛的生产基于在室内投喂高能量浓缩饲料。添加通常较为便宜的牧草，会降低育肥牛的生产成本，但可能会影响牛肉品质。因此，研究人员对126头大陆品种的肉用公牛进行了试验，这些公牛被分为三组，分别是：持续自由采食浓缩饲料直至出栏（C组）；先自由采食青贮牧草120天，然后再自由采食浓缩饲料直至出栏（GSC组）；先自由采食青贮牧草，接着在牧场放牧100天，之后再自由采食浓缩饲料直至出栏（GSPC组），并在目标胴体重分别为360千克、410千克或460千克时屠宰，随后对其牛肉的感官品质和成分进行了检测。结果显示，GSPC组牛肉的嫩度、风味喜好度和总体喜好度均低于C组和GSC组（P<0.05）。GSPC组牛肉的肌内脂肪含量和可溶性胶原蛋白比例低于GSC组（P<0.05），而GSC组又低于C组（P<0.05）。胴体重为460千克的牛肉的可溶性胶原蛋白比例低于410千克的（P<0.05），410千克的又低于360千克的（P<0.05）。添加放牧期会降低牛肉的嫩度、风味喜好度和总体喜好度评分，但公牛的屠宰年龄对感官特性没有明显影响。
