60～90日龄腾冲雪鸡肌纤维特性研究

 使用组织学方法,对16只60和90日龄的腾冲雪鸡的胸肌纤维直径、纤维密度进行了测定,并与体型指标和活体重进行了表型相关分析。结果表明同日龄公母鸡的肌纤维直径无显著差异（P＞0.05）,不同日龄的肌纤维直径差异极显著（P＜0.01）,60日龄时公母鸡的纤维直径分别为31.40±7.36 μm和32.36±8.11 μm,90日龄时公母鸡的纤维直径分别为38.68±9.42 μm和37.67±9.14 μm;因而90日龄以前上市的肉用仔鸡公母性别间肉的细嫩度差异较小。不同日龄纤维直径差异极显著,且年龄越大,肌纤维直径变大,表明肌肉细嫩度越差。随着日龄的增长,肌纤维同步增长,但肌纤维生长变异不大（P＞0.05）。肌纤维直径与鸡的日龄和胸宽有显著的表型相关关系（P＜0.01）,与龙骨长和活重有显著相关关系(P＜0.05）,因而这为肌纤维细度的表型选择提供了一定的方便。不同日龄和性别间单位面积内的肌纤维密度没有显著差异（P＞0.05）,但表现出随年龄增加密度加大和公鸡的密度大于母鸡的密度的规律, 60和90日龄时公母鸡纤维密度分别为1 165.12±58．86根／mm²和1 111.11±192.45根／mm²,1 231.48±242.63根／mm²和1 194.45±134.72根／mm²;肌纤维密度与体型体重和肌纤维直径也没有显著的表型相关关系（P＞0.05）,这种现象值得进一步深入的研究。

Study on Muscle Fiber Characteristics of Tengchong Snowcock at 60 and 90 Days

Sixteen breast muscle samples from male and female Tengchong Snowcock at sixty and ninety days were collected. Diameter and density of muscle fiber were measured with histological measures. Conformation parameters were scaled and living weight was weighed. The phenotype coefficient of diameter and density of muscle fiber with conformation parameters and living weight were calculated.The results shown that there is no significant difference(P＞0.05) between sex at same days in diameter of muscle fiber. while the significant difference exists between different days (P＜0.01).The diameters of muscle fiber in male and female Snowcock at 60 days are 31.40±7.36 μm and 32.36±8.11 μm respectively, while they are measured as 38.68±9.42 μm and 37.67±9.14 μm respectively at 90 days. Those imply that there are no difference in tenderness between sex at same days before 90 days. but the significant difference of tendermess as growth days increased. Because CV is less change (P＞0.05) as the age increased the growth of muscle fibers are synchronous. The phenotype coefficients of diameter of muscle fiber with breast width and days have great significant positive relationship (P＜0.01). The coefficients with living weight and length of chest bone are positive significant (P＜0.05). Those provide the patent means for selection of diameter of muscle fiber through indirect conformation parameters. There are no significant difference (P＞0.05) in density of muscle fiber (N／mm²) in different days and sex, but we can see the trends that the N／mm² in male is greater than that of female, and N／mm² of 90 days is greater than that of 60 days. The measured value of different age and sex are 1 165.12±58.86 N／mm² (male) and 1 111.11±192.45 N／mm² (female) at 60 days, 1 231.48±242.63 N／mm² (male) and 1 194.45±134.72 N／mm² (female) at 90 days. The phenomena that why the phenotype coefficient of density of muscle fiber with body conformation, living weight and fiber diameter need to study further.