Total mixed ration (TMR) silages were prepared using tofu cake, rice bran, or green tea grounds at 10, 20, and 30% dry matter (DM), respectively, with whole crop rice silage and commercial formula feed. Twenty experimental groups were prepared with or without lactic acid bacteria (Chikusol, 5ppm FM, and fermented juice of epiphytic lactic acid bacteria (FJLB), 2% FM). All experimental treatments were well prepared because pH values were less than 3.8, and lactic acid contents were more than 2.72% (FM). Lactic acid content for 30% tofu cake TMR silage was highest among treatments. In vitro DM digestibility for 30% rice bran TMR silage was highest among treatments, while methane production per digestible dry matter for 30% rice bran silage was lowest among treatments. In addition, pH was lower (P<0.05), lactic acid was higher (P<0.05), in vitro DM digestibility was higher (P<0.05), and methane production per digestible dry matter was lower (P<0.05) in those supplementation with lactic acid bacteria than in control.

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Under set stocking (S) and rotational grazing (R) by lactating dairy cows, effects of these grazing systems on sward structure, herbage production and utilization were examined at the same stocking rate. Two paddocks of 0.83 ha of grass-clover mixed pasture were assigned two treatments. Two different groups of each 5 lactating dairy cows were grazed on each pasture. Mean sward height during the grazing period was lower in S than R (P<0.05). Grass leaf mass in S was higher than that of post-grazing in R (P<0.05), whereas daily herbage regrowth did not differ between the treatments. The amount of dead material in S was higher than that of pre-grazing in R (P<0.05), and nutritive value of herbage in S decreased in summer. Daily herbage DM intake per cow in S tended to be higher than R in May and June due to large amount of herbage allowance, and consequently total herbage utilization during the grazing period in S was higher than R (11.2 vs. 7.0t DM/ha). Herbage utilization during the grazing period under set stocking would be no less than that of rotational grazing, although the amount of dead materials increased and nutritive value tended to decrease in set stocking through summer.

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To investigate the relationship between damage to Miscanthus sinensis tillers caused by cattle grazing and the survival and regrowth of the tillers, we measured the extent of damage (i.e., defoliation of leaves/shoot apices and trampling of tillers) and proportions of surviving tillers among 40 tagged M. sinensis tillers subjected to varying grazing intensities in late June, late August and late September. Among wintering tillers, high percentages of leaves were defoliated during the grazing seasons. During the June-August period, 20% to 48% of shoot apices were defoliated by cattle. The percentage of trampled tillers increased in proportion to grazing intensity during the August-September period. The proportion of surviving tillers was lower when shoots were trampled by cattle than when reduced by grazing. Mean leaf height in individual tillers, indicating the degree of regrowth after the last grazing period, generally declined due both to defoliation of shoot apices and trampling. Based on the relationship between the total proportion of tillers with defoliated shoot apices and trampling damage and grazing intensity for each season, our study suggests that Miscanthus grasslands can be maintained if cattle are allowed to graze at an intensity not exceeding 42 animal unit days/ha at the end of September, thereby minimizing the damage sustained by tillers that threatens M. sinensis survival in grasslands.

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This study evaluated nutritional status of Japanese black cows grazed on native, sown and native-sown mixed pastures by analyzing blood components. A blood sample was collected from the coccygeal vein of each cow before grazing. Groups of cows were grazed in one native pasture, three native-sown mixed pastures, and one sown pasture and blood samples were collected during the summer and autumn. In all pasture types, blood component concentrations of the cows before grazing and during the summer were within the normal range. However, increases in blood urea nitrogen and non-esterified fatty acid were observed in cows on the native pasture during autumn, suggesting excess protein and insufficient energy intake. Moreover, blood inorganic phosphate was lower in cows on the native pasture, indicating that phosphate intake was insufficient. Cows in the mixed pastures had increased blood urea nitrogen in autumn, but no energy or phosphate insufficiencies were observed. The results suggest that nutritional status should be considered when grazing cows extensively on native pastures.

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To examine the possibility of using cattle grazing to maintain the Swertia pseudochinensis Hara populations, we surveyed the small-scale population density of S. pseudochinensis and the vegetation structure in the grassland at the foot of Mount Sanbe, southwestern Japan, where grassland management practices have shifted from burning (mowing and burning) to cattle grazing. In the first year of grazing management (1996), the mean density of S. pseudochinensis was 5.8/m^2 in October, with a maximum of 41/m^2. After 9 years of grazing, only a few individuals of S. pseudochinensis occurred in October 2005, with a total of 2/50m^2. The number of species and coverage of ungrazed plants such as trees and scrubs tended to be more in the ninth year of grazing than in the first year, whereas those of herbaceous plants mostly decreased over the 9 years. With a closed canopy layer of dominant woody species, S. pseudochinensis could become extinct. This result suggests that when grazing cattle are used to conserve S. pseudochinensis, additional management practices such as burning and mowing might be required to control the spread of woody species in the pasture.

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Since cattle being grazed must walk slowly to graze, we tried to estimate grazing time of cattle by walking time calculated by data obtained from a hand-held global positioning system (GPS). Walking speed of multipara Holstein cows being intensively grazed was estimated about 0.29km/h from step length and numbers of step per minute. Moreover, the times during which cows walked slowly, namely at 0.25km/h to 0.60km/h calculated by positioning data obtained from a GPS device attached to each cow's head though low accurate distance at low and irregular walking like grazing, were in agreement with the grazing times estimated by bite counts of a bite-counter. During periods of high temperature, bite counts measured by the bite-counter sometimes showed that cows walking more slowly (less than at about 0.25km/h) do not graze. In these cases, little changes in data on positions of dairy cows in the pasture obtained by the GPS devices indicated nongrazing. The results indicate that it is possible to estimate grazing time of a cow by positioning data obtained from a GPS devices and walking time calculated from positioning data.

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We conducted field experiments to determine suitable application rates of nitrogen fertilizer for integrated cutting and grazing of perennial ryegrass/white clover swards in the Tenpoku region, Hokkaido. Before the first cutting in mid-June the swards were managed as a meadow. Following the first cut, they were cut five or six times (approximately once every 3 weeks) to simulate grazed pasture. Annual nitrogen fertilizer rates were 0, 30, 60 and 90kgN・ha^<-1>, half of which was applied in early spring in the meadow period, and half of which was given at the beginning of the pasture period. Among treatments, 30kgN・ha^<-1> gave the highest annual total dry matter yield, except in 2002 when drought occurred. Coefficients of variation for DM yield and legume ratio during the pasture period were lower at 30kgN・ha^<-1> than at the other two rates. Average legume ratio was higher (26%), and annual yields of total digestible nutrients, total nitrogen uptake and increase in DM yield per unit nitrogen applied were highest at 30kgN・ha^<-1>. Compared with 30kgN・ha^<-1>, 0kgN・ha^<-1> gave low DM yields, and 60 and 90kgN・ha^<-1> gave a low legume ratio. Therefore, a suitable application rate is 30kgN・ha^<-1>.

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In semi-natural grassland, the vegetation changes seasonally and annually. Therefore, to examine problems related to long-term vegetation change, we must understand the influence of study season on the vegetation diagnosis. This study investigated the phenological characteristics of Miscanthus (M)- and Zoysia (Z)-dominated grasslands. We established twenty 100×100cm quadrats in each grassland. In each quadrat, we identified all of the species, determined coverage and maximum height for each species, and vegetation cover and canopy height in spring, summer, and autumn. We calculated species diversity indices and vegetation similarity for each season. In both M- and Z-grasslands, the extended summed dominance ratios (E-SDR_2) of the dominant species changed seasonally. The number of species and vegetation height increased with the season in M-grassland, but not in Z-grassland. The vegetation similarity among seasons was lower in M-grassland. Therefore, the seasonal change in vegetation in M-grassland was greater than in Z-grassland. By contrast, the Shannon index (H') and Simpson index (D) differed little among seasons in each grassland, suggesting that the diversity index can be used to evaluate the grassland condition with long-term vegetation succession.

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