Larzul C, Lefaucheur L, Ecolan P, Gogué J, Talmant A, Sellier P, Le Roy P, Monin G
Station de Génétique Quantitative et Appliquée, INRA, Jouy-en-Josas, France.
J Anim Sci. 1997 Dec;75(12):3126-37. doi: 10.2527/1997.75123126x.
A total of 383 barrows and gilts from a French Large White experimental herd were slaughtered at 100 kg BW. Samples of longissimus muscle were taken to categorize myofibers according to their contractile (I, IIA, and IIB) and metabolic (oxidative and nonoxidative) properties. Myofiber percentages, cross-sectional areas (CSA), and relative areas were measured. Growth rate, carcass composition, muscle chemical composition, metabolic enzyme activities, and meat quality traits were also measured to estimate phenotypic and genetic correlations between these traits and myofiber characteristics. Genetic parameters were estimated using a REML procedure applied to an individual animal model. Heritabilities of fiber traits were moderate to high (h2 = .20 to .59). Highest heritabilities were found for type I fiber percentage (h2 = .46 +/- .11), type IIBw fiber percentage (h2 = .58 +/- .11), and type I fiber cross-sectional area (h2 = .59 +/- .10). For a given fiber type, the relative area was phenotypically and genetically more closely related to the percentage than to the CSA. Phenotypic correlations between fiber type composition and other traits were low. Genetically, growth rate, carcass leanness, and loin eye area were positively related to fiber CSA. Intramuscular fat content was not related to fiber type composition (r(g) = -.05 to .06), whereas it was positively related to fiber CSA (r(g) = .68). Type IIBw fiber percentage was related to pH at 30 min (r(g) = -.46), pH at 24 h (r(g) = -.62), glycolytic potential (r(g) = .31), and lightness of color (r(g) = .55) of longissimus muscle.
从法国大白猪实验猪群中选取383头公猪和母猪，在体重达100千克时进行屠宰。采集背最长肌样本，根据肌纤维的收缩特性（I型、IIA型和IIB型）和代谢特性（氧化型和非氧化型）进行分类。测量肌纤维百分比、横截面积（CSA）和相对面积。还测量了生长速度、胴体组成、肌肉化学成分、代谢酶活性和肉质性状，以估计这些性状与肌纤维特征之间的表型和遗传相关性。使用应用于个体动物模型的REML程序估计遗传参数。纤维性状的遗传力为中等至高（h2 = 0.20至0.59）。I型纤维百分比（h2 = 0.46±0.11）、IIBw型纤维百分比（h2 = 0.58±0.11）和I型纤维横截面积（h2 = 0.59±0.10）的遗传力最高。对于给定的纤维类型，相对面积在表型和遗传上与百分比的关系比与CSA的关系更密切。纤维类型组成与其他性状之间的表型相关性较低。在遗传上，生长速度、胴体瘦肉率和眼肌面积与纤维CSA呈正相关。肌内脂肪含量与纤维类型组成无关（r(g) = -0.05至0.06），而与纤维CSA呈正相关（r(g) = 0.68）。IIBw型纤维百分比与背最长肌30分钟时的pH值（r(g) = -0.46）、24小时时的pH值（r(g) = -0.62）、糖酵解潜能（r(g) = 0.31）和色泽亮度（r(g) = 0.55）有关。
