不同营养水平对杜—哈白F_1猪肌组织影响的研究

EFFECT OF DIFFERENT NUTRITIONAL STATUS ON THE MUSCULAR TISSUE OF F_1 HYBRIDS FROM DUROC AND HARBIN WHITE PIGS (D-H)

用光镜观察和测量了杜—哈F_1猪90公斤时肌组织的形态学特征:a.背最长肌(M.longissimus dorsi)和股二头肌(M.biceps femoris)基本上均属于中间型(氧化糖酵解型)纤维构成的肌肉,该纤维肌浆均匀,肌原纤维孔氏区(Cohnheim)明显。红肌纤维位于1级肌束中部,常以2,3条肌纤维集聚,形态多为圆形,其周围的肌肉膜清楚,常与周围中间型肌纤维分离,其肌浆充盈,故不易见孔氏区象。白肌纤维极少,肌浆贫乏,肌原纤维呈密集点状(横断面);b.F_1代猪肌小束(1级肌束)以35～50条肌纤维组成,小束间结缔组织膜H.E染色不清,仅以裂隙示之,但PAS染色,Osimic acid处理的肌组织Ⅰ级肌束膜清楚。以数条到十数条肌小束构成Ⅱ级肌束;c.F_1代猪肌纤维直径45～65微米,雌性的大于阉雄的;肌小束膜及肌束膜厚,阉雄的大于雌性的。d.股二头肌肌内膜比背最长肌肌内膜发达,说明背最长肌柔嫩、细腻,肉的品质高于股二头肌。e.根据观察和生物统计二因素方差分析表明,第1组早期18％,后期14％的蛋白及5％的鱼粉混合料对肌纤维粗度、密度有显著影响,但在肌纤维类型的比率上无明显差别。根据肉质标准,该组饲料配方效果,尚需商计。其它7组饲料配方,无规律性变异。

The results were as follows:1. The Musculi longissimua dorsi and M. biceps femoris of the F_1 hybrids consisted basically of medium-type (oxidationglycolysis type) muscular fibers, which had a homogenous sarcoplasm and showed a remarkable Cohnheim area of fibrils. The red muscular fibers were located in the middle of a fascicle which was also called primary bundle in this paper, they occured in groups of 2～3 fibers. The red fibers were, in most cases, round in cross section and were thicker than fibers of other kinds, and an endomysial capsule around them was discernible which often separated them from the medium-type fibers. Their sarcoplasm was so plentiful that no Cohnheim area could be discerned. The few white muscular fibers had very little sarcoplasm and the fibrils they contained appeared as densely populated dark dots in cross sections; 2. The fascicles consisted of 35～50 muscular fibers and the connective tissue membrane (perimysiura) between them were not distinct in H. E. sections and appeared only as a small gap. Treated with PAS method or osimic acid, the muscular tissue showed clear perimysium. Several or more than ten fascicles comprised a secondary bundle, and the inter-bundlar septum between the secondary bundle could be clearly revealed in H.E. sections; 3. Most of the fibers had a diameter of 45～65μm, and the female was superior to the male in the diameter and number of muscular fibers but the former was inferior to the latter in thickness of the perimysium and the inter bundlar septa. 4. The endo-mysium of the M. Biceps femoris was more developed than that of the M. longissiknus dorsi, indicating the latter was more tender and delicate, and better in meat quality; 5. The observation and the variance analysis showed that the mixed feed in the first group containig 18% protein and 5% fish meal had a considerable influence on the thickness and density of muscular fibers, but did not affect the proportion of different type of fibers.