Abstract
To evaluate the meat production and quality of Japanese Black cattle fattened with only self-sufficient herbage mainly grazing, three cattle at 8 months of age were grazed for about 38 months. The herds were grazed rotationally on sown pastures of Italian ryegrass (Lolium multiflorum Lam.) and native pastures dominated by Chinese fountain grass (Pennisetum alopecuroides (L) . Sprenge) . When the available herbage mass of the pastures was insufficient, silage was fed to the cattle on the grazed pasture.
At the end of the fattening period, average weight of the cattle was 450.7 ± 25.4kg and average daily gain was 0.27 ± 0.02kg/day in the fattening period. All the carcasses were graded as C-1 (lowest grade) according to the Japanese Grading Standards. The meat from the carcasses had less fat (14.2 ± 3.5%) and energy (2.12 ± 0.24kcal/g), and had higher conjugated linoleic acid (CLA) content (4.8-9.0mg/g fat) than the meat produced by fattening beef cattle under conventional fattening system as presented in Standard Tables of Food Composition in Japan (2008) . In sensory evaluation, almost of palatability attributes (smell, juiciness and flavor) of the grass-fed beef were lower than that of Japanese Black beef on the market.
In conclusion, our results show that grass-fed fattening cattle can reach a final body weight of about 450 kg in a period of 38 months for fattening and produce meat rich in CIA as one of the bioactive substances, though they show slower growth rate and a lower sensory evaluation in regard to their meat than that of conventional fattening beef cattle.
