Distance based multi-response permutation procedures are discussed in the context of analyzing the spatial relationship of short-grass prairie plant species. Under certain conditions, multiresponse permutation procedures may provide useful information on how the spatial relationship of multi-species populations change over large geographical area. This method is illustrated using mapped data of short-grass prairie plants typical of the eastern plains of Colorado. The use of permutation procedure for randomized block experiments indicated that the dominant species tend to be segregated on the four plots used in this study. The large value associated with the measure of agreement suggested a similar structure of the spatial distribution and association of individual species on the plots. Further analysis revealed that all but one of the dominant species occurred in clusters of varying size and density. The ability to study the spatial relationship among species on independent plots provides a valuable tool in studying the spatial dynamics of diverse populations.

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The resting sites of grazing cattle were examined in two hilly paddocks and the results from these two paddocks, and also for the paddock in our previous study, were compared in order to clarify the effect of topographic elements on the resting-site preference of grazing cattle in a hilly pasture. Cattle preferred to rest on relatively gentle slopes (0-15°) and avoided resting on steep slopes (25° or more). Resting frequencies on medium slopes (15-25°) varied among the three paddocks according to the total area of the gentle slope. Resting sites shifted between daytime and nighttime. In the two paddocks with elevation differences greater than 60m, cattle preferred to rest in the lower elevation zone in the daytime and in the higher elevation zone in the nighttime. However, this shift in resting site did not occur in the paddock with an elevation difference of approximately 40m. In all of the paddocks, cattle frequently rested around the ridgetop in the nighttime, and the resting frequency decreased with increasing distance from the ridgetop.

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The aspect of ruminal degradation with scanning electron micrograph for the botanical fractions (leaf blade, leaf sheath and internode) of straws from three rice varieties (AK: Akitakomachi, KH: Koganehikari, AH: Akihikari) was examined by incubating the straw samples in the rumen of sheep and related to rumen degradation characteristics including washing loss (WL), 48h dry matter loss (48h-DML), potential degradability and rate of degradation. There were no large differences in proportions of botanical fractions between varieties. The 48h-DML and rates of degradation were significantly varied among the varieties, while the WL and potential maximum degradability were not significantly variable. The intenode and leaf blade had significantly higher values of WL, 48h-DML and potential maximum degradability than the leaf sheath, and the degradation rate of the three botanical fractions was almost same. In the aspect of ruminal degradation with scanning electron micrographs, distinct differences in the degradation of tissue cell walls were observed both between varieties and between botanical fractions, showing that rumen microbial degradation of the AK variety and the internode or leaf blade was higher than the other rice vareities and leaf sheath, respectively. These aspects were coincided with the results of the 48h-DML described above.

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Yield and digestibility of napiergrass (Pennisetum purpureum Schumach) were compared under three levels of manure input up to 490 ton FW/ha/year in two years, aiming at clearing environmental pollution caused by dung and at improving forage productivity. Plants were grown from May 14 to November 6 and cut only once on September 8 in 1993. In 1994, plants were grown under three cutting intervals and three regimes of manure inputs. With increasing manure input in 1993, annual dry matter yields (TDMY), annual yields of in vitro digestible dry matter (TIVDDM), nitrogen concentration, in vitro dry matter digestibility and cellular contents tended to increase, while neutral detergent fiber content tended to decrease. TDMY increased with delaying cutting, while TIVDDM was higher in cutting interval of two months than in every month and no-cutting, and TIVDDM increased with increasing manure input in all cutting plots. Thus, it was suggested that the high level of manure input can improve not only dry matter yield but also forage quality of napiergrass, although the effect of manure input to increase TDMY tended to reduce as the level of manure input was increased.

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To clarify the effect of abscisic acid (ABA) on the development of freezing tolerance in Lolium multiflorum Lam. and L. temulentum L., we investigated the optimum exogenous ABA concentration for acquiring the freezing tolerance in seedlings, and compared the changes of freezing tolerance and endogenous ABA concentration by the ABA treatment with those by the hardening treatment. The highest level of freezing tolerance, based on the estimation of LT_<50> value (the temperature required to kill 50% of the seedlings), was achieved by treatment with 7.5×10^<-5>M ABA as foliar spray at intervals of 12h at normal growth temperature in either species. A comparison of ABA (7.5×10^<-5>M)-induced and hardening-induced freezing tolerance indicated that the ABA treatment increased freezing tolerance in 14 days, but did not completely substitute for the hardening. The ABA treatment also resulted in more rapid and great accumulation of endogenous ABA, as compared with the hardening treatment. Since the relationship between such an accumulation of endogenous ABA and the increase of freezing tolerance was not parallel, it is suggested that the development of freezing tolerance may not be dependent on endogenous ABA levels alone.

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Genotypic variations of resistance to snow mold caused by Typhula ishikariensis, freezing tolerance, and growth at low temperatures were examined in 21 European and four Japanese varieties of orchardgrass. Geographic origin of genotypes had a strong bearing on resistance to snow mold and freezing tolerance, which were closely correlated (r=0.89). The tolerance to winter stresses of genotypes from various regions could be ranked in descending order as follows: Russian and Norwegian groups≧Swedish and Japanese groups>East European group≧Central European group>French group. Tolerance to winter stresses and recovery of growth in spring were slightly correlated as some genotypes from the warm regions grew well at low temperatures despite their low winter hardiness. In contrast, the correlations between tolerance to winter stresses, resistance to stem rust and growth in late autumn were strongly negative. The results indicate that genetic resources from eastern Europe deserve special attention from the view point of improving orchardgrass in Hokkaido because of the similarity of latitude, compared to northern Europe and the continental climate with more severe winter than in western Europe as well.

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Rising behaviors during early germination characteristics of seeds were investigated to atain some informations for better seedling establishment of surface-sown herbage grasses. Tall fescue (Festuca arundinacea Schreb. 'Kentucky 31 fescue') and Italian ryegrass (Lolium multiflorum Lam. 'Sakurawase') were used for the examinations. Seeds of both species were put lemma-side down on the filter paper and germinated in constant 25℃. The timing of three germination phases as coleorhiza appearance, coloerhiza hair emergence and rooting of both species were observed both with rising behavior (RB) seeds and exposed-root (EB) seeds. The coleorhiza size, and number and maximum length of coleorhiza hairs of RB and EB seeds were also examined at the rooting time. In both species, coleorhiza thickness, number and length of coleorhiza hair in RB were significantly larger than those in EB. In the germination process of both species, coleorhiza hair of RB emerged earlier, while the rooting time was later than those of EB. Tall fescue, which has higher percentage of RB seeds as compared with Italian ryegrass, had longer adhering duration because of the late rooting. These facts suggest that the firm adhesion of coleorhiza hairs of RB may be achieved with its longer growing and adhering time together with its larger number and length in each species.

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It has been reported that broadleaf dock (Rumex ob-tusifolius L., abbreviated as Rx in the following), one of the most noxious weed in intensive pastures, produces a large amount of seeds and that seeds are stored in the seed bank of the soil for many years and germinate occasionally. Moreover, it has been reported that pastures of high frequency of Rx are the fertile soil, and on the contrary, these of low frequency of Rx are the poor soil. A survey on the buried seed population has been carried out on 4 pastures with high freqency of Rx and on 4 pastures with low frequency of that. The following results were obtained. 1) The highest and the lowest frequency (%) values of Rx in pastures were 30.3 and 0.9, respectively. The mean frequency (%) value of Rx was 14.2±11.1. 2) The buried seeds of thirteen weed species were found, such as Rx, Polygonum persicaria, Digitalia ad-scendens, D. violascens, Cyperus microiria, Stellaria neglecta, and Viola verecunda, etc. A large amount of seeds of Echinochloa crus-galli were found but they were not survived, therefore it was excluded from a statistical analysis and a discussion. 3) High correlation coefficients were found between the Rx frequency and a number of the buried seed of Rx, and also between the Rx frequency and that of the eutrophic weed species such as Polygonum persicaria, Digitaria ad-scendens, and Chenopodium album, etc. This suggests that pastures Rx occur abundantly preserve a large amount of the buried seeds of Rx as well as that of the eutrophic weeds.

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This study examined the effects of three water holding materials (vermiculite, Sphagnum and synthetic resin) added to the surface of low-moisture volcanic ash soil on the soil water content and early germination of orchardgrass. In Experiment 1, water content and water release of the materials and volcanic ash soil (untreated control) were measured for 7 days after they were soaked in water for a day. The water content and the released water volume during the 7-day period were significantly different among the materials, being ranked volcanic ash soil<vermiculite<Sphagnum<synthetic resin. In Experiment 2, low-moisture volcanic ash soil with or without water holding materials was oversown with orchardgrass, and soil water content and germination rate of seeds were measured for 7 days. The addition of the materials resulted in higher soil water content and germination rate as compared with the untreated soil. Experiment 3 showed that the increase in the germination rate with the application of the materials was enhanced by covering the seeds with soil. It was suggested that adding water holding materials to the surface of low-moisture volcanic ash soil promotes germination of orchardgrass directly drilled into deteriorated pasture sods by improving soil watercondition.

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We studied to use opal phytoliths as a marker for the identification of plant species ingested by grazing animals. The following 11 species were investigated, Orchardgrass (OG, Dactylis glomerata L.), Tall fescue (TF, Festuca ar-undinacea Schreb.), Perenial ryegrass (PRG, Lolium perenne L.), Reed canarygrass (RCG, Phalaris arundinacea L.), Susuki (Miscanthus sinensis Anderss), Ooaburasusuki (Spodiopogon sibiricus Trin.), Todashiba (A rundinella hirta C. Tanaka.), Shiba (Zoysia japonica Steud), Chimakizasa (Sasa palmata Nakai), Sweet vernalgrass (Anthoxanthum odoratum L.), Sedge (Carex spp.). OG, TF, PRG and RCG contained three types of opal phytoliths such as boat, hat and oblong. Other species contained the following characteristic opal phytoliths, Susuki and Ooaburasusuki; dumbbell and dumbbell B type, Todashiba; dumbbell, cross and saddle B type, Shiba; saddle B type, Chimakizasa; saddle type, Sweet vernalgrass; boat and boat B type, Sedge; conical type. OG, TF, PRG, RCG and Sweet vernalgrass classified into Pooideae were distinguished from the species of other subfamilies based on boat types of opal phytoliths. Sweet vernalgrass was also distinguished from 4 species of the same sub family by the existence of boat B type, but the remainders of grasses were hardly distinguishable. Susuki, Todashiba and Ooaburasusuki, which were classified into Panicoideae and contained dumbbell types of opal phytoliths, were distinguished from the species of other sub families. Todashiba was distinguished from 2 species of the same subfamily by the existence of cross type. Ooaburasusuki was distinguished from Susuki by dumbbell B which had specifically lobes more than 4 per side. Shiba was distinguished from other nine species by saddle B type, except for Todashiba. Other species were identified by each index opal phytolith. It is therefore possible to identify OG and TF in the pasture composed of only these two species, because of the difference of the composition of index opal phytoliths between OG and TF. Index opal phytoliths in OG, TF, PRG and RCG were formed through growth period. The compositions of the index opal phytoliths in all tested plants were slightly changed with plant growth, while these were some at the heading stage. The compositions of the index opal phytoliths was variable between in the leaf blade and sheath of OG, showing no effect on identification of plant species, which was associated with main ingestion of leaf blade by grazing animals for grazing use under short height. These results suggest that the opal phytolith is useful marker for identification of plant species ingested by grazing animals.

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It is important to maintain proper botanical composition and produce forages with more than 65% in total digestible nutrients (TDN contents) in timothy (TY)-white clover (WC) mixtures in Konsen district, Hokkaido. This research was carried out to investigate the effects of stages, interval and frequency of cutting on botanical composition, dry matter yield and TDN contents. TDN contents were higher in the early harvest (EH) treatments (66-69%, cuts at the booting or the first heading time of TY) than in the control group (63%, twice cuts at each heading time of TY). Early harvest for three years resulted in dominance of WC and decrease in dry matter yield and density of TY tillers in EH treatments. However, those problems were solved by limiting early harvest to only one year and by ensuring the longer regrowing period after the 1st cutting. From the above results, the 1st cutting at booting-initial heading time of TY and the 2nd cutting 55-60 days after that proved to be a proper cutting management of TY-WC mixtures in Konsen district. It was advisable that the 3rd cutting should be avoided. And it was also important that the early harvest of TY-WC mixtures should be restricted to only one year to maintain good botanical composition.

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Effect of stocking rate on herbage utilization were studied in lactating Holstein cows. Cows (average BW=594kg, days in milk=47.2) were divided into two stocking rates; L=five cows/ha, and H=seven cows/ha. Cows were allowed to graze 5 hours daily from May to October of 1993 and 1994 at Experimental Farm, Hokkaido University, under time-restricted grazing system. Total numbers of cows grazed in 1993 and 1994 were: L=825 and 828, and H=1062 and 1153, respectively. In 1993, daily herbage utilization was almost equal in both groups (51 to 53kgDM/ha), but the annual herbage utilization of H was lower than L (7.9 vs. 9.1tDM/ha). Higher stocking rate in 1993 reduced sward height (8 to 17cm). This might be due to the shorter grazing cycle for H during spring of 1993 (4 to 8 days) compared to L (12 to 22 days). Also, total number of grazing days was shorter for H compared to L (156 vs. 171 days). However, there was no difference between annual herbage utilization of H and L (9.9 vs. 9.6tDM/ha) in 1994, when herbage was utilized in proportion to the seasonal changes of daily herbage production.

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The chemical composition and in vitro dry matter digestibility (IVDMD) of nine Italian ryegrass (Lolium multi-florum Lam.) varieties were investigated at first cutting, second cutting and third cutting. And the nutritive values of six varieties were evaluated at first cutting in this study. The organic matter content was high and crude protein and ether extract content were low mostly in the order of first cutting, second cutting and third cutting. On the contrary, IVDMD of second and third cuttings were lower than those of first cutting in general. Dry matter digestibility, energy digestibility, total digestible nutrient, digestible energy and metabolizable energy of Uzukiaoba were higher than those of other varieties. Nutrient yields of Miyukiaoba and Nagahahikari were higher than those of other varieties. Nitrogen intake and nitrogen excretion in urine of Uzukiaoba, Waseaoba and Tachiwase were higher than those of other varieties, and there were no apparent differences in nitrogen excretion in feces. There were no apparent differences in energy intake, energy excretion in urine, in methane and heat production. Energy excretion in feces of Uzukiaoba was lower than that of other varieties. From the above, it should be emphasized that nutritive value have to be taken into account when we select to use Italian ryegrass in company with dry matter yield, operating aptitude and cropping system.

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The effects of addition of formic acid, bacterial inoculant or mixture of bacterial inoculant and enzyme on fermentation quality of unwilted herbage silage were investigated using the first and second cut timothy (Phleum pratense L.), orchardgrass (Dactylis glomerata L.) and alfalfa (Medicago sativa L.) with laboratory silos. The both first and second cut herbages harvested at three growth date. The water-soluble carbohydrate (WSC) contents in the first cut timothy, orchardrass and alfalfa were 4.5-7.5%, 5.9-10.3%, 4.9-6.0% on dry matter basis, respectively. The WSC contents in the second cut orchardgrass and alfalfa were lower than that in the first cut herbages. The fermentation quality of the silages was influenced by thegrowth date of the herbages prior to ensilages. The extent in variation of fermentation differed from the species of herbage material, the growth date, the cutting frequency and the additives. In the untreated first cut orchardgrass silage and untreated and inoculant and enzyme-treated first cut alfalfa silages, the extent in variation of fermentation was markedly high. The variation in the formic acid-treated silages was slight in all species of herbages. The fermentation quality of the formic acid-treated first and second cut timothy silages, orchardgrass silages and alfalfa silages were higher than that of the untreated silages. The formic acid-treatment was markedly effective in improving the fermentation quality for alfalfa silages. The fermentation quality of the inoculant-treated first and second cut timothy silages were higher than that of the untreated silages but the extent in improving the fermentation quality of the second cut orchardgrass silages was lower than that of the first cut silages. The first and second cut alfalfa silages were not improved by the inoculant-treatment. The fermentation quality of the inoculant and enzyme-treated first and second cut timothy and orchardgrass silages were higher than that of the untreated silages. The fermentation quality of second cut orchardgrass silages was higher than the inoculant-treated silages. The fermentation quality of the inoculant and enzyme-treated first and second cut alfalfa silages were slightly higher than that of the inoculant-treatment but there were no significant differences between the inoculant and enzyme-treated silages and the untreated silage. From the above results, the effectiveness of the additives on the silage quality depends on the species of herbage materials used, the growth date and the cutting time.

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The present study was conducted to compare chewing behavior and passage rates of digesta in wether fed timothy (Phleum pratense L.) hay at three different maturities (preheading, heading and seed setting). Twelve wethers (average weight 62.3kg) were randomly divided into three groups and fed 1000g hay once daily. The crude protein, neutral detergent fiber and acid detergent lignin contents on dry matter basis of hay were 9.6; 62.9; 3.3%, 6.8; 70.0; 5.5%, 4.8; 70.0: 6.9%, for preheading, heading and seed setting, respectively. Apparent digestibilities for hay decreased with advancing maturity. The daily time spent ruminating was significantly shorter for preheading hay than for heading and seed setting hay. Ruminal fluid passage rates calculated from feacal excretion curve of Co-EDTA were not different among three stages of growth. In contrast, ruminal particulate passage rate calculated from feacal dysprosium excretions of setting hay was significantly slower than that of preheading hay. Total mean retention time for seed setting hay was longer than that for preheading and heading hays. These results suggested that maturity of timothy hay affects ruminal particulate passage rate, and also indicated that ruminal passage of digesta was closely related with physical particle size reduction by mastication.

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Sixteen wethers (average weight 62.3kg) were used in the experiment with a 2×2 factorial design to investigate effects of soybean meal (SM) supplement on digestibilities, chewing time and passage rates of digesta. Diets were 1) 900g timothy hay harvested at heading stage without SM, 2) 900g timothy hay harvested at heading stage with 200g SM supplements, 3) 900g timothy hay harvested at seed setting stage without SM, 4) 900g timothy hay harvested at setting stage with 200g SM supplements. SM supplement increased apparent digestibilities of acid detergent fiber, neutral detergent fiber and cellulose in wethers fed heading stage hay. There was no difference in hemicelluloce digestibilities between with and without SM supplementation. The ruminating time and total chewing time of wethers fed either heading or seed setting timothy hay were significantly decreased by SM supplementation. No significant differences were observed in ruminal fluid and particulate passage rates between with and without SM supplementation. These results indicated that soybean meal supplemenatation improved digestion of forage fiber, but did not affect the rates of passage of particulate digesta throgh the rumen.

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This study was conducted to investigate the effects of waterlogging treatment on the contents of cell wall constituents and minerals in Aeschynomene americana cv. Glenn introduced recently from Australia. Glenn was grown in pots and treated with four different durations of waterlogging, i.e., 0 (control), 10, 20 and 30 days from the 14th day after germination. At the end of respective periods of waterlogging, pots were drained and held on the same condition as control till the 40th day after the start of treatment. Mineral contents in the plant were measured on the 10, 20, 30 and 40th day after the start of waterlogging treatment. Cell wall constituents were determined on the 40th day. Cellulose and lignin contents in the plant top with 30-day waterlogging were higher than those of control. In the root, hemicellulose and lignin contents were lower with longer period of waterlogging compared with those of control. Calcium and magnesium contents decreased with waterlogging treatments, but their accumulation rates in the plant top during the period of 20-30th day of waterlogging were similar to those in control. Specific absorption rates (SAR) of calcium and magnesium in the plant from 20 to 30 days of waterlogging were higher than those in control. Potassium, phosphate, manganese and iron contents were higher in waterlogging treatment than in control. In the root, iron and manganese were higher when exposed to longer period of waterlogging condition. Accumulation rate of iron in the top of the plant was higher in waterlogging treatments than in control treatment.

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Palatability of 14 varieties of orchardgrass (Dactylis glomerata L.) was evaluated with heifers by using a trough cafeteria method for 4 years. The main varieties used in this study were Akimidori, Makibamidori, Lude, Lully, Lutetia, Prairial, Potomac, Cambria, Sylvan and Jesper. Akimidori was used as the standard variety in this study. The value of palatability of variety was calculated as difference between the intake per diet of the variety and that of Akimidori. Highly significant differences in the palatability of varieties were recognized throughout the growing seasons in each year. Except for the reproductive stage, Lude, a French variety, showed excellent palatability for most seasons of the years. Palatability of each individual variety varied considerably with seasons and years. Interactions between variety and season were recognized in 1991, in 1992 and in 1993. Interactions between variety and year were also recognized in the period of June to July and of August to September. But no interaction between variety and year was detected in the period of October to November. It indicates that the ranking of palatability among varieties might be stable in the autumn season. The effect of animal differences, breed differences and rearing background on the palatability of variety was briefly discussed.

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A total of 17 agronomic characters in 16 varieties of orchardgrass (Dactylis glomerata L.) was evaluated for 5 years in connection with the study on their palatability, which was mainly measured by Holstein heifers. Relationship between palatability of varieties and their agronomic characters was investigated throughout the growing seasons. In spring, degree of heading was negatively correlated with palatability. In summer, flexibility of leaf and stem was positively correlated and two kinds of disease (Rhynchosporium scald and summer blight) were negatively correlated with palatability, respectively. In autumn, one disease (stem and leaf rust) and ratio of dead leaf to whole leaf were negatively correlated with palatability. But there was no relationship between palatability and leaf characters, such as width, thickness, length, degree of serration and of trichome. Palatable variety Lude was found to be flexible and resistant to several diseases, except for summer blight. As the selection criteria for the improvement of palatability in orchardgrass, flexibility, resistance to leaf diseases and lower ratio of dead leaf were considered to be the most important agronomic characters.

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The morphology of macropores in the root zones of grassland in Brown forest soil, England, was investigated in the present study. The structure of macropores was determined by three dimensional stereoscopic-radiography of macropore morphology and examination of the physical condition of the soil. The soil samples were collected from four layers of root-zones that were shallower than 85cm in depth in a 14-year-old perennial ryegrass pasture. Each soil layer had a clay texture, and was dense and solid. The porosity rate was between 54% (surface layer; 0-5cm) and 38% (subsoil layer; 80-85cm). The non-capillary pores of the first soil layer (0-10cm) consisted of pores formed by earthworms and aggregates, and in the second to the fourth soil layers (10-85cm) the pores were formed by roots. The capillary pores in the surface layer (first layer) consisted of pores formed by roots and pores of inter-particles and inter-aggregates. In the subsoil layer, the capillary pores were formed by roots. Thus, similar to the pore morphology of the Andosols, Steppe soil cases and Red yellow soil, most macropores of grassland in Brown forest soil, England, are tubular in shape and formed by plant roots.

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