Tiller increase and rhizome development as well as herbage production and animal performance were investigated for 3 years in Kentucky bluegrass (Poa pratensis L.) pastures, to which Glyphosate had been applied soon before seeding to kill dominant weeds. The tiller density of Kentucky bluegrass had reached approximately 10,000 per square meter by next spring. Following the temporary decrease during reproductive stage in May and June, the tiller number increased again and recovered previous value in a shorter period, and continued gradual increase until autumn. Rhizome elongation started after the completion of dense tiller population. Fairly quick herbage growth at the rate of 2.4-4.6g/m^2/day was achieved in the spring following the seeding year. This might be brought by the high tiller density realized through the utilization of the weed control prior to seeding of Kentucky bluegrass. The total length of rhizomes per square meter, however, was only 5m in the winter of the seeding year. Vigorous rhizome elongation started the next spring, and the total length increased to 150m/m^2 by July. It is therefore recommended that the commencement of grazing be delayed or that the grazing intensity be reduced in the following spring. In July, when the developed rhizomes become dense in the subterranean zones of pasture and many new tillers have begun to appear on the ground, a grazing intensity of 3 heads per hectare can be expected.

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We assessed winter survival for three varieties of rhodesgrass (Chloris gayana Kunth) at three different sites and seasonal productivity at one site to identify rhodes-grass varieties that can survive winters and be productive in the growing season. Three varieties of "Asatsuyu", "Katambora" and "Hatsunatsu" were sown in early May 1999, 2000 and 2001 to determine the dry matter yield by 4-5 cuttings in the growing season and winter survival at the Nagasaki Prefectural Livestock Experiment Station. Winter survival rates of "Asatsuyu" and "Katambora" were evaluated in two consecutive winters in Miyazaki, Miyazaki Prefecture and Fukue island, Nagasaki Prefecture. In the summer period of low solar radiation, the dry matter yield was higher in "Asatsuyu" than in "Katambora". The dry matter yields at the final cuttings in autumns in 1999 and 2000 tended to be higher in "Asatsuyu" than for the remaining two varieties, suggesting that "Asatsuyu" grows more rapidly under low temperatures. Winter survival was higher in "Asatsuyu" than in "Katambora". This high rate is related with a larger stubble size of "Asatsuyu" before winter and its higher amount of non-structural carbohydrate in subterranean stems in winter. As the plants were cut earlier before winter, winter survival tended to be higher in Rhodesgrass. Winter survival and dry matter yield at the first cutting in the next early summer were higher in "Asatsuyu" than in "Katambora", both in Miyazaki and Fukue island. These results revealed that "Asatsuyu" is highest in winter survival and dry matter productivity among examined varieties, suggested that "Asatsuyu" is the most suitable variety of Rhodesgrass in the light-frosted areas of the south-western warm regions of Japan.

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Two experiments investigated animal performance of Holstein steers (avg. body weight 250 and 232kg/head). Results showed development of an intensive grazing system in which put-and-take stocking was carried out with timothy (Phleum pratense L., TY) dominant swards (1.2ha×4) and perennial ryegrass (Lolium perenne L., PR) dominant sward (2.3ha). Experiment 1: The put-and-take stocking (PTS) herds were grazed continuously without supplement from May to October on TY swards. After early-August, two heads of each herd were excluded from PTS herds. The short time rotational grazing (SRG) herds were grazed rotationally on TY swards with adjustment grazing area. These herds were supplied with silage made from these swards after summer season. The average daily gain of PTS herds and SRG herds were 0.87kg/day/head and 0.97kg/day/head, respectively. And the average cumulative body weight gain of PTS sward and SRG swards were 668kg/ha and 718kg/ha, respectively. Experiment 2: From May to early-July, 39 heads of steers were grazed rotationally on the TY swards. In early-July 19-20 heads of this herd were transferred to PR sward. In addition, 2-4 heads of the herd transferred between PR sward and TY swards to adjust grazing pressure. The herd on PR sward was grazed continuously with silage supplements made from this sward at early-June and early-July. The average daily gain of TY sward herd and the PR sward herd were 0.90kg/day/head and 0.91kg/day/herd, respectively; that of all steers was 0.91kg/day/head. The cumulative body weight gain of the steers over the grazing season was 815kg/ha of grazed pasture which was higher than those of SRG swards described in Exp. 1.

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Animal performance and carcass quality of Holstein steers, which were grazed on a farm to 5-12 months age before fattening periods (Grazing herd: G herd), were compared with those which were fattened using only a conventional system (Control herd: C herd). The G herds, replicated three times during 3years (G1, G2 and G3 herds), consisted of 34-39 Holstein steers (Average body weight 243kg/head). Grazing of G herds was conducted intensively using timothy (Phleum pratense L.) and perennial ryegrass (Loliume perenne L.) swards through the raising period. Then the G herds were fattened about 12 mo. Thereby, total feeding periods of G herds were 545 days. Control herds were two (18 heads and 21 heads: C1 and C2 herd), which were introduced into the farm at the same time as G3; the average body weight of C herds was 263kg/head. C herds were fattened without grazing for about 18 mo. The average feeding period of the C herd was 536 days. Feeding stuff through the fattening period in G and C herds consisted of formula feed (TDN: 71.3%, DCP: 11.4%), food manufacturers' by-product (TDN: 94.8%, DCP: 7.7%) and cane-top. Average body weights at the end of fattening in G and C herds were 805kg/heads and 835kg/head, respectively. Average daily gain (DG) of G herd through the grazing period (0.93kg/day) was lower than that of the C herd through the same period (1.01kg/day). However, DG of the fattening period in the G herd was higher than that of the C herd. Therefore, the DG of whole feeding period in the G herd was similar to that of the C herd (1.04kg/day and 1.06kg/head, respectively). Average carcass weights in G and C herds were 446kg and 474kg. The percentages of carcass over grading 3 of Japanese beef carcass grading standards in G and C herds were 58% and 59%, respectively. Moreover, fewer condemned viscus cows were in the G herd (3/39 heads) than in C herd (9/36 heads).

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In the public-run farms of northern Tohoku, we have generally sown pastures with orchardgrass (Dactlis gromerata L.) or perennial ryegrass (Lolium perenne L.). However, Kentucky bluegrass (Poa pratensis L.), introduced before and naturalized, frequently replaced those grasses as a dominant species throught grazing use year after year. We conducted this experiment to evaluate the real animal productivity of Kentucky bluegrass dominant pastures subjected to rotational grazing by Japanese shorthorns in Morioka during 2002 and 2003. High grazing capacity about 600 CD (Cow day) per hectare could be obtained with 200-day grazing periods from late April to early November in both the years. Furthermore, the grazing capacities before and after August were similar. Herbage yields were kept uniform from spring to late autumn, enabling the same number of grazing heads to be raised throughout the grazing periods. In addition, herbage nutrition analysis revealed sufficient levels to sustain animal growth and health with high CP, Ca, Mg, P, TDN and mineral balance like K/Ca+Mg(meq.) ratio and NO_3-N concentration, although the K content was high. Kentucky bluegrass had been regarded as a low-productivity species. However, Kentucky bluegrass pastures examined in rotational grazing use in the northern Tohoku exhibited high ability to raise breeding cows with productivity and quality of nutrition of herbage as well as mineral content.

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The objective of the study is to know the influence of level of concentrate on performance of free-ranging fattening pigs, on the deteriorated pasture and also the effect of grazing on cleaning of vegetation in the pasture. Experimental paddocks mainly composed of Pennisetum alopecuroides and Pteridaceae aquilinum var. latiusculum. Ten fattening pigs (LDW) were allocated to one of three treatments and reared outdoor during fattening period. In the control treatment (C), pigs were offered concentrate at 120% level of Japanese Feeding Standards. In the middle level treatment (M), pigs were offered concentrate at 80% level of C treatment. In the low level treatment (L), pigs were offered at 60% level of C treatment. There was no significant difference in daily weight gain (about 600g/day) between C and M (p>0.05). Concentrate requirement was the lowest for pigs in the M treatment. There was no significant difference in carcass dressing percentage, backfat thickness and carcass grade (p>0.05). In all the treatments, vegetation coverage including Pennisetum alopecuroides and Pteridaceae aquilinum var. latiusculum were almost eliminated by grazing pigs at the 74^<th> day after beginning of grazing.

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Two total mixed rations (TMR) of rice whole crop silage (RWCS-TMR) and Sudangrass hay (SGH-TMR) were investigated on dry and lactating cows to determine the feed property and animal performance, respectively. The RWCS was lower in contents of crude fiber and neutral detergent fiber than the SGH, in accordance with its higher contents of nitrogen-free extracts and non-fiberous carbohydrates (NFC). On a constant feeding trials of RWCS-TMR and SGH-TMR, the RWCS-TMR showed a significantly (P<0.05) lower TDN content as compared to that of SGH-TMR, although their TDN and CP contents were designed to be the same by being composed of 21% SGH or 21% WRCS on DM basis. The RWCS-TMR also had lower digestibilities of starch and NFC (starch: P<0.01, NFC: P<0.05) than the SGH-TMR, as shown by over 60% excretion of indigested rice grains in feces. As a lactation trial was conducted with dry matter composition of 21% SGH and 26% WRCS in the corresponding of the two TMRs, respectively, the DM intake by lactating cow was not different between the two TMRs, while the fat-corrected milk and solids not-fat contents were lower with the feeding of RWCS-TMR.

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Balance trials using lactating Holstein cows in early lactation were conducted to compare the feeding value of "Hoshiaoba" which is a new breed of rice for whole crop silage with that of timothy hay. Three cows were fed the diet consisting of 35% (on a dry matter basis) timothy hay and 65% concentrates (Timothy treatment) and two cows were fed the diet consisting of 35% "Hoshiaoba" and 65% concentrates (Hoshiaoba treatment) during the trials. The ingredient composition of the concentrates in the two treatments was the same. In "Hoshiaoba" silage and timothy hay, the content of crude protein, nitrogen cell wall free extracts, and organic cell wall (OCW) were 6.7 and 8.2%, 23.2 and 17.3%, and 55.0 and 67.3%, respectively. Dry matter intake of "Hoshiaoba" silage (46.5g/kg metabolic body size/day) tended (P<0.10) to be lower than that of timothy hay (60.4g/kg metabolic body size/day). The digestibility of OCW in Hoshiaoba treatment was lower (P<0.05) than that in Timothy treatment. As a proportion of gross energy, urinary energy tended (P<0.10) to be lower, and methane energy or heat production were statistically higher (P<0.05 or P<0.10) in Hoshiaoba treatment than those in Timothy treatment. Fat corrected milk (4%) yield was not significantly different between Timothy treatment (32.5kg/head/day) and Hoshiaoba treatment (31.4kg/head/day). Although "Hoshiaoba" silage contained lower amount of organic cell wall, roughage value index in "Hoshiaoba" treatment was similar to Timothy treatment. The average excretion rate of ear and unhulled rice of "Hoshiaoba" silage into feces were 30.2 and 22.7%, respectively. These results suggested that dry matter intake and OCW digestibility of "Hoshiaoba" silage was decreased compared with timothy hay, and "Hoshiaoba" silage exhibited 30.2% in excretion rate of ear, because of their hard texture. In order to improve the feeding value of "Hoshiaoba" silage in Holstein cows, it is necessary to improve dry matter intake as well as digestibility of ear of "Hoshiaoba" silage.

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Five imported grass hays (oat, sudan grass, tall fescue, bermudagrass and timothy) were evaluated by palatability test with dry cows, feeding trials with lactating cows, in vitro digestibility with rumen fluid and counting the numbers of chewing in lactating cows. The daily intakes of hay dry matter were 7.6^<abcd>, 7.0^<cd>, 6.8^d, 8.1^b and 9.0^a kg per cow, and the daily milk yields were 26.5, 25.7, 25.0, 25.2 and 25.5kg per cow on the oat, sudan grass, tall fescue, bermudagrass and timothy respectively (a, b, c, d different superscripts are siginificantly different, p<0.05). The following equations ware obtained for hay dry matter intake (HDMI) from in vitro digetion data: HDMI=0.707×CW digestion rate (%)-1.64×lag time (hr)+8.0 (R^2=0.91), and HDMI=0.26×12hr digestibility (%)-1.2×lag time (hr)+7.9 (R^2=0.98).

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Estimates of starch contents in whole crop rice silage and cattle feces were obtained using enzymatic analysis and the conventionally used perchlorate-glucose oxidase method. They were then compared to determine the simpler estimation method. Results for starch content by enzymatic analysis were not always the same as those by the conventional method. However, the regression equations of y=0.34+0.97x(r^2=0.997) for whole crop rice silage and y=-0.55+1.49x(r^2=0.996) for feces were significant (P<0.01) where y and x indicated starch content by the conventional method and that by the enzymatic analysis. Digestibility of starch calculated using the starch content in diet and feces by enzymatic analysis was not significantly different from that by the conventional method in either lactating dairy cows or steers. These results indicate that enzymatic analysis using the above regression equations is applicable to determine starch content of whole crop rice silage and starch digestibility in cattle fed whole crop rice silage.

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The heading responses of six cultivars of sorghum having maturity genes Ma_1-Ma_4 were compared with those of seven cultivars having T, D_1 and D_2 genes, which regulate flower initiation. In addition, the relationship between these two genotype groups in the heading responses was analyzed by progeny tests. From the results, it was shown that the heading responses of six cultivars having Ma_1-Ma_4 genes could be explained by those of cultivar having T, D_1 and D_2. From the heading response of the cultivar 100M to the extremely low temperature on late June in 2002, it was suggested that 100M had the thermo-sensitivity gene T. The presence of gene T in 100M was confirmed by the heading response of the test cross F_1 (MS 79.A×100M). Furthermore, from the the delay of 60M by exposure to minimum temperature over 20℃, the presence of the thermo-sensitivity gene T in 60M was suggested. The heading response of F_1 (390A×60M) could be explained by the presence of gene T in 60M.

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In order to evaluate the effects of the brown midrib-3 (bm3) gene in maize (Zea mays L.) on stover digestibility and yield, 24 hybrids, including 12 pairs of bm3-type and its normal counterparts, were investigated. The content of organic cellular content (OCC) of stover in bm3-type hybrids was almost equal to that in normal-type hybrids, and the content of highly digestible fiber (Oa) of stover in bm3-type hybrids was 3.1 points higher than that in normal-type hybrids. Ear and TDN contents in the whole plant of bm3-type hybrids were higher than those of normal-type hybrids. Although the average silking date of bm3-type hybrids was 2 days later than that of normal-type hybrids, the average dry matter yield and average TDN yield of bm3-type hybrids were 0.12kg・a^<-1>・day^<-1> and 0.06kg・a^<-1>・day^<-1> lower than those of normal-type hybrids, respectively. However, a few of bm3-type hybrids showed earlier silking dates than their normal counterparts, while a few other bm3-type hybrids showed higher TDN yields than their normal counterparts. The influence of the genotypic background on the rate of lodged plants was greater than that of the bm3 gene. Consequently, while the digestibility of stover was improved by the bm3 gene, silking was delayed and yield was reduced. However, the degree of silking delay and yield reduction by the bm3 gene was varied according to the genotypic background.

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Phosphorus is one of the most important limiting nutrients in Brazilian grasslands. Therefore, the function of soil microorganisms, especially arbuscular mycorrhizal fungi (AM fungi), has been attracted considerable attention, because AM fungi can absorb phosphorus from soil and supply it to host plants. To clarify their function in the Agropastoral system, the AM fungi in some fields in the Agropastoral system experiment in Brazil was investigated. The colonization of AM fungi was higher in soybean roots in the Continuous Crop field than in grass roots in Continuous Pasture and Degraded Pasture. Spore density was higher in the Continuous Crop field, where soybean was cultivated, than in the Pastures. Especially, Gigaspora sp. was abundantly found in the Continuous Crop field. These results suggest that even if the fields are close to each other, the dynamics of AM fungi is different probably due to different host plant species and fertilizer conditions.

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Fermentation quality of a wrapped silo prepared by a roll baler for chopped maize and a bale wrapper were investigated in a field test to verify the practicality of the machines developed by IAM-BRAIN. The investigation revealed that the fermentation quality of the silage in the wrapped silo was excellent after one year. In addition, no practical problems of the fermentation quality were discovered, even when the material contained a high volume of water that produced drainage or soil adhered when the bale was released. Fermentation quality remained high for five days even in summer when 18cm thickness of silage was removed from the wrapped silo everyday. Furthermore, sorghum, oat and rhodesgrass ensiled in the wrapped silo fermented well.

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