In order to clarify the growth pattern of body measurements of Japanese Black beef steers, the body measurements were collected from 801 steers of Japanese Black cattle on progeny testing at Miyazaki and Kagoshima Prefectural Livestock Experimental Stations from 1986 to 1993. Four non-linear models (Logistic, Gompertz, Von Bertalanffy and Brody) were used to fit growth patterns of the body weight (BW), withers height (WH), hip height (HH), body length (BL), chest girth (CG), chest depth (CD), chest width (CW), rump length (RL), hip width (HW), thurl width (TW) and pin bone width (PBW) . The coefficients of determination were more than 70.0% for all body measurements except TW and PBW fitted by four non-linear models. Logistic model was the best fitted of all non-linear models for every body measurement of Japanese Black steers. The mature estimate of body measurements of fattening steers were 913.5 kg, 167.1cm, 197.2cm and 273.9cm for BW, HH, BL and CG by use of Logistic model, respectively. Estimated BW was reached to 66.6% of predicted mature size at the end of fattening (about 20 months of age) and also reached to 77.4-81.5% for other body measurements.

View full abstract

The ultrasonic estimates were conducted on two hundred and thirty eight Japanese Black steers of progeny testing from 1987 to 1990 at Miyazaki and Kagoshima Prefectural Experimental Stations. All animals were ultrasonically scanned from 2nd to 12th month by two months intervals of fattening. The carcass traits such as M. longissimus thoracis area between 6th and 7th ribs ( MLTA1) and 12^th and 13^th ribs (MLTA2), subcutaneous fat thickness (SFT), intermuscular fat thickness (IMFT), rib thickness (RT) and beef marbling score (BMS) were estimated from each scanogram. The total gain of ultrasonic estimates of carcass traits were used as the dependent variables for predicting by means of multiple regression analyses with use of independent variables such as ultrasonic estimates of carcass traits and body measurements at each scanning stage of fattening.
The total gain of ultrasonic estimates of MLTA1, MLTA2, SFT, IMFT, RT and BMS were well predicted by multiple regression equations after 6 months of stage of fattening. Standard partial regression coefficients of carcass trait were estimated for predicting the total gain that ranged among 0.552-0.885, 0.347-0.835 and 0.409-0.858 of gain of MLTA1, MLTA2 and BMS from initial (2^nd-4^th month) to final (2^nd-10^th month) stages of fattening, respectively. The ratios of contribution of MLTA1, MLTA2 and BMS were more than 60.0% after 6 months of stage of fattening. In the case of gain of SFT, IMFT and RT there were also relative high in partial regression coefficients on each stage adapted to multiple regression equation for predicting the total gain of these traits with ratios of contribution more than 50.0% after 6 month s of stage of fattening.

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

The experiment was conducted to evaluate the fermentative quality of napier grass silage added with 10% beet pulp as an additive and investigated the effect of feeding of this silage on beef cattle (16-months aged Japanese Black steers) performance during two months period, comparing with guinea grass hay. The ratios of forage (silage or hay) to concentrate in the diets in terms of TDN were 14-19% as feed budgets in the 2 feeding systems. The ensiled napier grass silage indicated a high fermentation quality of pH 3.9, 74% lactic acid in the total acids and TDN 62%, comparing with hay of TDN 56%. Forages in each feeding system were con-sumed about the same amounts of dry matter, while concentrates were consumed 0.3kg less in the system based on silage than on hay. Live weight gain of 1.26kg/day was achieved in the system based on silage, comparing with 1.11 kg/day in the system based on hay, although the difference was not significant. It is evaluated that napier grass silage added beetpulp shows high fermentative quality and can be utilized as a basal feed for beef cattle.

View full abstract

In this study, we attempted the application of several biotechnology techniques to the Kuchinoshima wild cattle, endangered Japanese cattle.
On a result of measurement of their shapes, it was rather small in stature than that of Japanese black. Five Kuchinoshima wild cattle, four Japanese black and two F1 (Holstein × Japanese black) cattle were inseminated artificially by using frozen-thawed epididymal spermatozoa of wild cattle which had been cryopreserved by standard technique in a liquid nitrogen (LN₂) . Seven out of 11 cows (including 3 wild cattle) became pregnant. When in vitro matured oocytes collected from Japanese black were fertilized with frozen-thawed epididymal spermatozoa of wild cattle, 69.3% (296/427) oocytes cleaved and 25.8% (110/427) of them developed to blastocysts. Embryo collections were conducted on three superovulated wild cattle which were inseminated with frozen-thawed ejaculated spermatozoa of Japanese black, but only one of them produced transferable embryos. Embryo transfers were conducted on 3 recipient cows and one of them became pregnant.

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract