Mixed swards of galega (Galega orientalis Lam.) and timothy (Phleum pratense L.) were established with 4 seeding rates of galega, as well as single-sown swards of each two species, and yearly changes of their growth were observed for five years. The growth of galega sown alone was inferior to that of timothy for two years after seeding, and then the plant vigor of galega is same or high, compared to timothy. For two years after seeding, the yields of mixed swards of galega and timothy were same as the single-sown swards of timothy, but higher than that of galega alone. However, since the third year after the seeding, the yields of mixed swards exceeded those of the single-sown swards of each species. When the seeding rate of galega was 2-4 kg/10a, botanical composition of galega and total dry matter yield during the five years were significantly higher than those at the seeding rate of 1kg/10a. Therefore, it is considered that the appropriate seeding rate for the galega and timothy of mixture is the combination over 2kg/10a of galega seeds and 1kg/10a of timothy seeds.

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We studied two grazed pastures (10a×2) in order to establish an appropriate sward height at the end of grazing period to allow sustainable vegetation and pasture production under rotational grazing in Japanese lawngrass (JL) pasture. The herbage in the pastures was consumed by grazing cows until the sward height reached the low sward height (LS) of 5cm or the high sward height (HS) of 10cm during each rotational grazing period in 2006 and 2007. In JL-covered areas in the pastures, JL maintained its domination both in LS and HS pasture, while plants other than JL increased in HS pasture. Though the dominance of unpalatable plants in non-JL-covered areas increased in HS pasture, it did not increase in LS pasture. A decrease in the regrowth rate of aboveground biomass and herbage consumption in HS pasture was observed. The total number of grazing cows in both years was more than 1.3 times larger in LS pasture (over 900 cow-day ha^<-1> year^<-1>) compared to that in HS pasture. Therefore, in rotationally grazed JL pasture, the sward height at the end of each grazing period must be considered as part of the grazing management.

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We investigated the effects of feeding whole-crop rice silage (rice-WCS), prewilted to reduce β-carotene content to about 2.8mg/kg DM, on feed intake, growth, blood components, and carcass traits in Japanese Black steers. This diet, fed during the fattening period, was substituted for hay and rice straw. Eighteen steers were divided into 3 groups: control (n=6), fed Italian ryegrass hay and rice straw during the early (8-13 months of age) and late (14-24) stages, respectively; WCS-rice straw (n=6), fed on rice-WCS and rice straw during the early and late stages, respectively; and rice-WCS (n=6), fed on rice-WCS during both stages. Daily dry matter intake was significantly higher in the rice-WCS group. Although insignificant, plasma retinol levels tended to be higher in the rice-WCS group than in other groups. Daily dry matter intake in the rice-WCS group was 1.58kg, and the plasma retinol level decreased to 50IU/dL at 19 months. Differences in daily weight gain (>0.8kg in all groups), carcass grade, and beef marbling scores were not significant among all 3 groups. The fat color score was estimated as 3 for each of the 18 carcass. Thus, rice-WCS with reduced ,β-carotene content is a recommended diet throughout the fattening period for Japanese Black steers.

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Both Italian ryegrass "Magnet" and tall fescue "HiMag" contain high concentrations of magnesium; these lines were developed to minimize the hazards of grass tetany in grazing cattle. Each of these line was compared with three commercial cultivars in terms of forage productivity and mineral composition at four harvests, where for Italian ryegrass in 2003 and for tall fescue in 2003 and 2004. The magnesium, calcium, and potassium concentrations were analyzed using an energy dispersive X-ray fluorescence spectrometer JSK-3220. The forage productivities of Italian ryegrass "Magnet" and tall fescue "HiMag" were slightly lower than those of other cultivars. These lines had the highest magnesium and concentrations and lowest K/(Mg+Ca) among the studied cultivars at all four harvests. Because cultivar selection with the purpose of increasing the magnesium concentration is likely to lead to a high calcium concentration and low K/(Mg+Ca) equivalent ratio, the use of a high-magnesium grass is expected to lower the incidence of grass tetany, although these cultivars tend to have slightly lower productivity.

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Grass lines with high magnesium concentration have been developing to minimize hazards of grass tetany in ruminant. To know the effect of higher Mg concentration for digestibility, two high-Mg lines Italian ryegrass 'Magnet' and Tall fescue 'HiMag' were compared with three commercial cultivars of each species. Enzymic hydrolysis method was applied to partition dry matter into three cellular constituents. These lines were evaluated at four harvests, where for Italian ryegrass in 2003 and for tall fescue in 2003 and 2004. Both of 'Magnet' Italian ryegrass and 'HiMag Tall fescue were higher in cell content, high-digestible cell wall composition, and TDN and lower in low-digestible cell wall composition at all four harvests. There was no difference in ash content of both high-and low-digestible fractions. Several highly positive correlations were obtained between Mg concentration and high digestible cellular fractions including TDN. Many negative correlations were obtained with low-digestible cell wall composition. These results indicate that selection to higher Mg concentration is not linked with lower digestibility.

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In Japan, there has been an increase in the use of abandoned cultivated lands for cattle grazing. It is important to clarify plant succession on these lands for assessment of the sustainability of grazing. We investigated the dynamics of dominant wild plants after the introduction of grazing onto the abandoned lands in western Japan using questionnaires. The main plants before the introduction of grazing were paddy field weeds, Miscanthus sinensis, and Solidago altissima in the order of frequency. The abandoned lands most frequently became dominated by Zoysia japonica after introduction of grazing. In a few cases M. sinensis or S. altissima remained dominant after 4 or more years of grazing. Imperata cylindrica var. koenigii remained dominant in most of the cases, even 10 or more years after grazing in several cases. Paddy field weeds declined within 1 year after grazing in some cases ; however, they did remain dominant for longer periods in several cases. Dwarf bamboo was found to be dominant for 10 or more years after grazing in several cases, while it did not become dominant. Most of the Pueraria lobata that were dominant before introduction of grazing became nondominant after introduction of grazing.

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Investigations were carried out on the effect of difference of sowing times on growth of galega (Galega orientalis Lam.) in the second year. In the case of sowing from early in June to early in July, the growths of galega in second year were excellent on plant height and dry matter yield. After those sowing times, the growths of galega in second year were reduced. The results of regression analyses indicated that the effects of sowing times were larger for galega than alfalfa on the growths in second year. Therefore, early sowing time is essential for steady cultivations of galega. It is estimated that the sowing time of galega for establishment of good stands is late in July approximately two weeks earlier than that of alfalfa, which is early in August.

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This experiment evaluated the effect of fertilizer nitrogen rates of 160 and 240kg/ha/year on forage composition, sugar content and silage fermentation of timothy (Phleum pratense L.) pure sward. The contents of neutral detergent fiber, acid detergent fiber and crude protein of grass grown in 240kg N/ha were higher than those in 160kg N/ha, and the contents of each sugar in 240kg N/ha were lower than those in 160kg N/ha. The grass grown in 240kg N/ha gave poorer quality silage than that in 160kg N/ha. These results indicate that excess N application of 240kg N/ha has negative effects on forage composition, sugar content and silage fermentation, and therefore, it is important to apply the appropriate rate of N fertilization.

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