东北民猪、长白猪和三江白猪的个别肌肉相对生长模式的研究

本文对试验数据分别以半胴重、半胴肌肉重、腿臀部重和腿臀肌肉重做自变量按比量方程(y=ax~b)分别计算了a(截距)及b(生长系数)值,根据方差分析结果计算了R~2(相关指数)和S_y(剩余标准差)。结果表明,在所有四种不同自变量情况下,后腿五块肌肉的早熟性顺位均有各自品种鈞一致性,显示出品种间遗传差异特征:民猪均以半膜肌为最早熟,而长白猪和三江猪均以股薄肌为最早熟。当以半胴重和腿臀部重做自变量,各肌肉的6值:长白猪最高,民猪最低,三江猪居中。当以半胴肌肉重和腿臀部肌肉重做自变量时,三品种猪各肌肉b值具有共同的趋势:半腱肌b值最高,半膜肌R~2值最高。研究证明,民猪的内收肌和长白猪的半膜肌最近似各自品种的半胴肌肉总重和腿臀部肌肉重的生长势模式。

STUDIES ON THE RELATIVE GROWTH PATTERNS OF INDIVIDUAL MUSCLES AMONG MIN ZHU, LANDRACE AND SANJIANG WHITE PIGS

Data of the present study were obtained from the dissection of 90 pig carcasses among three breeds: Min Zhu, Landrace and Sanjiang White. 3 barrows and 3 young female pigs of each breed were serially slaughtered at either 15, 30, 60, 90 or 120kg liveweights. After slaughter, the left side of the carcass was jointed into forequarter(neck+shoulder+rid), loin and hindquarter(ham+leg). Each joint was then physically separated into muscle, fat, bone and skin. Five muscles in the ham joint: m. gracilis, m. biceps femoris, m. adductor, m. semitendinosus and m. semimembranosus and longissmus dorsi of loin joint(1st-5th lumbar vertebrae)were separated intact from their tendons at the muscle margins. Data for individual muscles and total muscle in the side and the weight of left side(half carcass weight)were transformed to logarithms to establish part-to-whole aIlometric relationships according to the allometric equation y=axb: logy=blogx+loga; y being the dependent variables(part),x the independent variables(whole), 伪 the intercept and b the regression coefficient or referred to as the growth coefficient. Growth patterns of the individual muscles were examined by taking each of the following as the independent variable: half carcass weight, ham joint weight, total muscle in half carcass or in ham joint. Growth patterns of individual muscles were classified according to the system proposed by Butterfield and Berg(1966) as either high, average or Iow impetus for comparison with other published results. Growth patterns of individual muscles were described using the growth coefficients(b) from the allometric equation. Growth coefficient data indicated significant differences among breeds: Landrace surpassed the Min Zhu and Sanjiang pigs in all individual muscles examined, with the Min Zhu the lowest and an intermediate position inclined toward the Landrace for the Sanjiang White. Results of the present study suggest that there is a tendency for the fattest breed, Min Zhu, to have the lowest allometric growth coefficients of the individual muscles and total muscle on carcass weight, and the leanest, Landrace, to have the highest, and the SW to have a patterns of the muscles was established, i. e.; them. semimembranosus is the earliest maturing for Min Zhu, with the m. gracilis the lowest for Landrace and Sanjiang wnite. There is a good agreement between the growth impetus patterns of the five muscles in ham joint examined in the present study and those corresponding values reported for Large White and Pietrain breeds (Davies, 1974), and for Landrace x Large White cross, and for Harbin White (Qi Shou-rong, 1981). But apparent homogeneity of growth patterns of the individual muscles among breeds was found by taking total muscle in half carcass as independent variable. Of the six muscles examined, the growth coefficient of the m. semitendinosus had the highest value (latest developing). By taking either half carcass weight or totl muscle weight in the half carcass as independent variables, the results indicated that the of the m. semimembranosus for cated that the proportionate growth patternes of the m. semimebranosus forLandrace were most closely related to total muscle weight in the half carcassand in the ham joint, suggesting the possibility of using certain individual muscles in the ham joint to predict total muscle in the side. Of the six muscle examined, the m. semimembranosus had the highest predictive value for Landrace and the m. adductor for for Min Zhy, Further work is required to clarify such relationships.