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Volume 47, Issue 6
Displaying 1-7 of 7 articles from this issue
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Tatsudo TAMURA1976 Volume 47 Issue 6 Pages 347-353
Published: June 25, 1976
Released on J-STAGE: March 10, 2008
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Yoshiyuki SASAKI, Keiichiro ETO, Fumio MUKAI, Kiyoshi NAMIKAWA1976 Volume 47 Issue 6 Pages 354-358
Published: June 25, 1976
Released on J-STAGE: March 10, 2008
JOURNAL FREE ACCESSThe possibility of assessing the breeding value of active sires in terms of the marketing performance of their progenies which were marketed by many individual fatteners was examined. Factors affecting performance of steers were also studied. Multiple regression analyses were conducted for marbling score as a function of age of slaughter and final weight, and for carcass merit as a function of final weight and other carcass characteristics. The data used in the analysis were collected on 224 steers from 13 sires at Osaka Central Market from 1971 to 1974. They were marketed from three regions of Oita prefecture. A least squares analysis with regression was carried out as described by HARVEY. Each trait was classified by the region at which the steer had been fed, by year in which that was marketed and by age at marketing. Most of the traits were affected significantly by year and by interaction between region and year. Significant partial linear-regression coefficients of final and carcass weight on slaughter age were found. None of the traits was affected significantly by differences between sires. Therefore, their heritability estimates were low. The results of multiple regression analysis based on step-wise method indicated that the greater part of the variation in marbling score was attributable to differences between ages of slaughter rather than those between final weights. Marbling score was the most important predictive variable for carcass merit. The effectiveness of "on-farm progeny testing" in selecting genetically excellent sires is uncertain.View full abstractDownload PDF (351K) -
Yoshiyuki SASAKI, Hiroaki IWAISAKI, Fumio MUKAI, Kiyoshi NAMIKAWA1976 Volume 47 Issue 6 Pages 359-370
Published: June 25, 1976
Released on J-STAGE: March 10, 2008
JOURNAL FREE ACCESSThe objectives of this study are to investigate the inheritance of type traits and to obtain some means to select for carcass value in Japanese Beef Cattle. At first, factors affecting 28 descriptive type traits and final score were studied. The type traits were evaluated by the descriptive classification method which was instituted by the Wagyu Registry Association in Japan. The data on 1338 heifers, belonging to 89 sires, which had been raised in five different prefectures and averaged 23.6 months old were recorded by the Association in 1973 and 1974. A least square analysis with regression was carried out as described by HARVEY. Each trait was classified by region where the heifer had been raised, by year when it was judged, by sire to which it belonged and its age at judging. Over all means of descriptive traits indicated that hair color and skin color in quality, fore quarter, rib and belly in middle quarter, etc. had been considerably improved in heifers, while impressiveness, thigh in hind quarter, etc. had not been yet. All traits with the exception of "neck" and "udder" were affected significantly by region. Some traits, especially quality and dairy characters were affected by year and by the interaction between region and year. The image of heifer herds in each prefecture was provided by least square means by region and year. That is, the herd in Hyogo prefecture was excellent in quality characters, while that in Kagoshima was excellent in body capacity and stature, fore quarter, middle quarter and hind quarter characters. The herd in Tottori demonstrated the same pattern as that in Kagoshima. Least square means in Miyazaki were equal or superior to over all means in all traits. Partial linear or cubic regression coefficients of several traits on age at judging were significant and negative. Sire effect was significant in all traits except for "shoulder (side view)", "loin" and "feet". It was suggested from these results that characteristics in type of both an animal and a herd could be visualized by the descriptive classification method. Genetic differences were found in most of 28 traits, which would provide breeders with the useful information for selection.View full abstractDownload PDF (662K) -
Yoshiyuki SASAKI, Hiroaki IWAISAKI, Fumio MUKAI, Kiyoshi NAMIKAWA1976 Volume 47 Issue 6 Pages 371-377
Published: June 25, 1976
Released on J-STAGE: March 10, 2008
JOURNAL FREE ACCESSHeritabilities and phenotypic and genetic correlations of 28 descriptive type traits and final score were estimated. The data of 1338 heifers which were 23.6 months old in average, descended from 89 sires and raised in five different prefectures were recorded by the Wagyu Registry Association of Japan. Paternal half-sib correlations were used to obtain the geneticparameters. Variance components were estimated using a least square analysis by HARVEY and covariance components were estimated using the modified HARVEY'S method. Estimates of the heritability of "ordinary hair" and "skin" which were important for quality evaluation, and dairy characters were relatively high; 0.25-0.34, while those of "feet" and "hoof" were low; 0.04 and 0.12, respectively. The heritabilities of beef characters ranging from 0.00 to 0.25 were nearly equal to or lower than that of final score of 0.19. The phenotypic correlations between descriptive traits and final score indicate that body capacity and stature, impressiveness, fore quarter, middle quarter and hind quarter characters are regarded to be more important at judging than quality, dairy and feet and hoof characters. Final score was highly correlated genetically with body capacity and stature, impressiveness, and hind quarter characters showing figures higher than 0.50, followed closely by fore quarter. However, the genetic correlations between final score and quality and dairy characters were intermediate or low (-0.15-0.41). Most of genetic correlations among descriptive characters with the exception of quality characters were sizable and positive. "Ordinary hair" and "skin" in quality characters positively and highly correlated genetically with impressiveness, dairy and feet and hoof characters, but did not with body capacity and stature, fore quarter, middle quarter and hind quarter characters. It is generally favorable that any genetic correlations among traits were not seriously negative. However, the genetic correlations between quality characters and final score, and between quality characters and body capacity and stature, fore quarter, middle quarter and hind quarter characters were relatively low. These facts should be taken into consideration in judging to improve Japanese Beef Cattle for qualitative and quantitative excellence.View full abstractDownload PDF (476K) -
Toshio YAMAMOTO, Seiji KUSUHARA, Kazuo ISHIDA, Motoji YAMAGUCHI1976 Volume 47 Issue 6 Pages 378-384
Published: June 25, 1976
Released on J-STAGE: March 10, 2008
JOURNAL FREE ACCESSThe purpose of this study is to investigate the influence of castration on the ultrastructure of fibroblasts distributed in the intermediate layer of cocks' combs. Single-Comb White Leghorn cocks were divided into three groups; capons, testosterone-injected capons and intact cocks. Various shapes of fibroblasts observed in testosterone-injected capons and intact cocks were arbitrarily divided into three types (types A, B and C). The rough endoplasmic reticulum of type A fibroblasts, well-developed and elongated, tended to run parallel with each other: relatively narrow cisternae contained homogeneous materials: extremely well-developed Golgi complex contained clearly observable lamellae, vesicles and sac structures filled with low electron-dense materials: at the peripheral regions were observed many small vesicles. Type B fibroblasts had extremely long cytoplasmic processes extended into various directions: the rough endoplasmic reticulum was very well developed: different from those in type A, the endoplasmic reticulum whose cisternae are filled with flocculent materials widely dilated, ramified and anastomosed: the Golgi complex was well developed like those in type A: the small vesicles at the peripheral regions were less in number, though the filaments spread in the cytoplasm abundantly. Type C fibroblasts, all spindle-shaped and containing smaller amount of cytoplasm, were considered to be resting fibroblasts: the rough endoplasmic reticulum and Golgi complex showed the poorest development; the small vesicles and filaments were scanty. In capons' combs were found two types of fibroblasts (types D and E): the former had cytoplasmic processes extended into collagen fibers and a small amount of cytoplasm in which poorly developed rough endoplasmic reticulum and Golgi complex as well as scanty small vesicles and filaments were observed. The latter which was spindle shaped had a small amount of cytoplasm in which poorly developed rough endoplasmic reticulum and rather indistinct Golgi complex were observed. These results seem to suggest that the fibroblasts undergo following changes; resting status→type A status where production of collagen and acid mucopolysaccharides is quite active→type B status where collagen production ceased→resting status. Types D and E fibroblasts in capons, basically resembling each other, are considered to be resting like C and to grow into types A and B with the help of testosterone.View full abstractDownload PDF (2171K) -
Kousaku TANAKA1976 Volume 47 Issue 6 Pages 385-392
Published: June 25, 1976
Released on J-STAGE: March 10, 2008
JOURNAL FREE ACCESSThe insertion of an artificial yolk (A. Y.) into the oviduct and the prevention of oviposition by a surgical means or by injection of progesterone were performed to investigate the initiation of secreting egg shell material in the uterus. The insertion of A. Y. into the oviduct of intact hens near the time of ovulation resulted in a normal deposition of shell around an A. Y., while the majority of A. Y. s inserted after lay of a terminal egg of the clutch were expelled prematurely. Premature lay was also observed without exception when an A. Y. was inserted into an emptied oviduct several hours after ovulation. The prevention of such a premature lay by removal of the ovarian follicles led to a deposition of shell around an A. Y. No additional calcification took place when the egg was forced to stay in the uterus for about 1 day or more beyond a normal period unless the ovum ovulated next had entered the oviduct during the prolonged period of stay of the preceding egg. It may be suggested that the stimulation of the oviduct cephalic to the uterus is necessary for initiating the secretion of shell material and that the ovulation system is associated with a regulatory mechanism by which the egg is held in the uterus until a completion of shell formation.View full abstractDownload PDF (422K) -
K. AGO, M. KOZAKI, T. NAGANO, K. TANAKA, M. TAKAHASHI, S. SUZUKI1976 Volume 47 Issue 6 Pages 393-394
Published: June 25, 1976
Released on J-STAGE: March 10, 2008
JOURNAL FREE ACCESSDownload PDF (167K)
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