In order to clear the possibilities to increase the TDN concentration and to maintain the fiber content for forage maize by breeding, comparisons were made between isogenic materials ; normal form (1/2 of plants) and bm_3 form (1/2 of plants) obtained by triple crossing, which parents were yellow dent hybrids (S_4 lines homozygous for normal allele × S_6 line homozygous for bm_3 allele) derived from American hybrid and synthetic variety, and the pollen parent was a white flint inbred lines (S_1 line homozygous for the bm_3 allele) from a Yugoslavian local variety. The normal and bm_3 stands were established by thinning after confirming the brown pigment on the midrib. Plants were ensiled at yellow-ripe stage, 99 days after seeding. We investigated the chemical composition, quality of fermentation, in vivo digestibility and nutritive value of whole-plant silages by goat digestion trials. Urea was added to the silages to provide the similar content of crude protein (CP) at about 12%. Grain contents in the whole-plant silage was about 45% for each phenotype. The contents of moisture, CP, ether extract, nitrogen free extract (NFE), crude fiber (CF), crude ash, starch, nitrogen・cell wall free extract (NCWFE), fiber fraction in NFE, organic cellular content and organic cell wall (OCW) did not differ between phenotypes. The pH, concentrations of organic acids and volatile basic nitrogen, and Flieg's score were similar. The digestibilities of OCW, CF, and fiber fraction in NFE were 16%, 11% and 25% higher for bm_3 than the normal on average, respectively. Therefore, digestible organic matter (DOM) and TDN were significantly higher by 4.0% and 4.1% for bm_3 silages than the normal (P<.001). The concentrations of TDN in dry matter for bm_3 silage reached about 78-79% by using oven-drying moisture analysis at 135℃. When freeze-drying method was used, the DOM and TDN were evaluated as 76.4% and 80.2% on average, respectively. The high concentrations of DOM and TDN for the bm_3 silages will concern the effects of bm_3 gene, grain content and maturing.

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Effects of Lactobacilli inoculation to clarify fermentative quality of silage and changes in microflora during ensilage were investigated with laboratory silo. The silage material was Italian ryegrass with 82% moisture and 8.8% water soluble carbohydrates on dry matter basis. Two strains of Lactobacillus, L. casei inoculant commercially named Snow Lacto L and L. plantarum inoculant commercially named Silogen, were used. Treatments used were L. casei (Lc), L. plantarum (Lp) and control. Treatments Lc and Lp were inoculted at the rate of 1.6 × 10^4 and 2.2 × 10^5/g of silage material, respectively. Effects of the inoculation were investigated by tracing the pH value and changes in microflora on 1, 2, 4, 7, 14, 30, 50 and 100 days of ensiling. The results are summarized as follows ; Silages with Lactobacilli obtaind a rapid pH decline and more lactic acid content but silage without Lactobacilli contained great amounts of butyric acid and showed higher pH value and higher ratio of volatile basic nitrogen to total nitrogen (VBN/T-N). Therefore, the fermentative quality of silage was largely improved by Lactobacilli inoculation. Each strain of Lactobacilli in the silage grew vigorously and was able to compete with other bacteria such as Gram negative bacteria and yeast. As a result, silages with Lactobacilli were kept below the critical pH (4.2) level of clostridia development. Silages with Lactobacilli had almost no clostridia while silages without Lactobacilli had many clostridia from 14 days until 100 days of ensiling. From the above results, it is confirmed that the inoculation of L. casei or L. plantarum has beneficial effects on inhibiting growth of harmful bacteria as well as improvement of fermentative quality in silages.

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On a tallfescue (Festuca arundinacea) pasture, energy flow from herbage to grazing Holstein heifers were estimated based on measurements of herbage production, cattle gain and cattle heart rate under grazing condition. Relationships between following constituents were investigated and energy efficiency was discussed. 1) DA (Daily herbage allowance, sum of actual gross energy intake by grazing cattle and energy contained in herbage left at higher part than 5 cm above ground.) 2) GE (Gross energy intake calculated from Linehan's equation). 3) ME (Metabolizable energy intake calculated from HP + RE). 4) RE (Retention energy by grazing cattle calculated from ARC's equation). 5) EC (Energy cost calculated from HP - F). HP (heat production) was estimated from heart rate. F (fasting metabolism of grazing cattle) was calculated from ARC's method. DA, GE, ME, RE and EC were expressed in terms of multiples of fasting metabolism of grazing cattle (dimensionless). DA ranged from 10.4 to 12.9, had significant correlation with ME, and the regression equation was estimated as ME=0.36DA-1.46. Significant relationships were obtained between GE and ME, ME and RE, EC as the following regression equations : ME=0.33GE-0.10 RE=0.25ME-0.56 EC=0.75ME-0.43 The regression of GE on ME represents an energy efficiency from GE to ME. The regression coefficients of ME on RE, and that of ME on EC were regarded as energy efficiency of utilization of ME for weight gain and energy cost for grazing, respectively. Almost all of RE obtained on this investigation were lower than that of estimation from ME based on the ARC's method. Maintenance requirement of ME was 33% higher than that of ARC's estimation, suggesting higher energy expenditure for grazing condition.

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It is well known that dead grass roots and underground rhizomes are accumulated in thatch as root mat in aged permanent grasslands. This report describes processes of root-mat formation using six cool-season grass species : Dactylis glomerata (L.), Phleum pratense (L.) Lolium perenne L., Festuca arundinacea SCHREB., Poa pratensis L. and Agrostis alba L. Differences in root mass accumulation were discussed in relation to its renewal and decay. The results were as follows : 1. Accumulation of root mass with ageing process was highest in P. pratensis. In P. pratense, root weight increment was rather steady from seeding year until first harvestirg year. 2. Loss of root mass was highest both in P. pratense and L. perenne, followed by P. pratensis and A. alba. Root decaying was slowest in D. glomerata and F. arundinacea. Specific differences in the loss of root mass were discussed with special reference to the sizes of root diameter, lignin content within the roots. 3. A remarkable increment of root mass according to the ageing process of P. pratensis was considered to be due to the increase of dead root resulting from high summer temperature in addition to active rhizome production. In case of P. pratense, root renewal and decay were estimated to be well-balanced during the first harvest year, so that the plants could survive without suffering from root mat formation.

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Trends of formation and senescence of leaves, length of successive component organs (leaf blades, leaf sheaths and internodes), and total length of reed canarygrass (Phalaris arundinacea L.) tillers in swards with different cutting frequency and nutrient level were investigated during growing seasons in 1987. the leaf appearance on each growing tiller (16 tillers per treatment were examined in every growth period of swards) was rather rapid and regular with the rate of around 6-7 days/leaf during the first half period of each primary and aftermath growth, irrespective of cutting frequency and nutrient level (Fig. 1, Table 2). The death of 1st leaf was observed in the beginning of May in primary canopy or in ca. 20 days after previous cutting in aftermaths, and the leaf death gradually extended upwards. The rate of leaf senescence proceeded much more slowly than that of the leaf formation, resulting gradual increment of living leaf numbers per tiller during each growth period. The increase of tiller length was most abundant in the latter half period of primary growth and was suppressed a little in autumn, however, the difference in length increment of tillers was rather small among seasons (Fig. 2). The pattern of tiller elongation fairly resembled under different managements and seasons, that is, the first rapid growth of tillers continued until they attained ca. 30 cm height, being followed by short rest period of elongation, and thereafter quicker increment in tiller length was resumed. Leaf blade length of tillers in each period increased successively until leaf blade attained maximal size at 6th to 7th phytomer which was counted acropetally from the first blade-bearing leaf, and subsequently it got shorter size (Fig. 3). During the course of growth in primary canopy, lower internodes which attached to the same phytomer units of first few successive leaf blades remained very short in length, whereas 4th or much higher-positioned internodes got successively longer size, terminating at 9th to 10th phytomer because of ear formation. Although elongation was short in first 2 to 3 nodes, successive internodes elongated rather longer inspite of vegetative growth in aftermath canopies, resulting higher C/F ratio in swards with longer regrowing pariod (Table 3). The estimation of total length of internode elongation at each leaf age by finding the remainder of tiller length and uppermost expanded leaf length (leaf blade + leaf sheath) suggested that abrupt internode elongation would occur at the beginning of May (ca. 30-35 days after sprouting in early spring) or about 25 days after each cutting, when the 2nd rapid increase of tiller length began (Fig. 4). Highly positive correlation between DM yield of swards and C/F ration (Fig. 5) indicates that the internode elongation of each shoot component in swards may perform the most important part for high and seasonally-balanced DM production in reed canarygrass. This high shoot growth rate should be derived partly from the regular diversion of the growth distribution pattern from the initial leaf formation to the preferential internode elongation which prepares a new active sink for dry matter accumulation in the shoot.

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It has been reported that alfalfa deproteinised juice (DPJ) has a comparatively small amount of sugars, and also it has some soluble substances that prevent yeast from growing luxuriously. But in the present experiment, almost the same amount of yeast yield was obtained on DPJ by steam coagulation when compared to the yield from mixed juice of malt, yeast extracts, glucose and peptone. Yeast yields were less on DPJ which was obtained from green juice (GJ) fermented anaerobically than from that of steam coagulation ; addition of glucose or (NH_4)_2SO_4 and KH_2PO_4 to it was not effective. But, when it was treated with resin Diaion HP-20 yeast yields were improved, and supplementation of (NH_4)_2SO_4 and KH_2PO_4 after treatment with Diaion resulted much more yeast yields. The DPJ obtained from glucose added and anaerobically fermented GJ did not prevent yeast growth and was better than that of fractionated DPJ by steam coagulation as the yeast culture. The best yeast yield was obtained when it was treated with Diaion HP-20 and then added (NH_4)_2SO_4 and KH_2PO_4. Although treatment with Diaion HP-20 improved a little yeast yields, but it is not suitable practically from economical point of view for unconcentrated DPJ in green crop fractionation (GCF) process.

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There were abundant crushed wood fragments (CWF) upon and in the seedbeds after establishing a ploughless pasture by a new method with a stumpcutter-bushcutter system. We investigated the effects of the coverage of CWF and the water supply from the soil on the initial growth of herbage on the seedbeds. Most of stumps, cut-branches and cut-trunks were distributed on the ridge-shaped slopes and/or the valley-shaped slopes before establishment. They were crushed into CWF during establishment and then they were distributed almost uniformly on the whole surface of the test field. It seemed that the initial growth of the herbage (Lolium perenne L., Dactylis glomerata L., Poa platensis L., and Trifolium repens L.) was influenced not only by the quantity (the coverage of surface of seedbed) of CWF but also by the capacity for holding and supplying water from the soil related with the micro-topographic characteristics of the slopes. 80 days after the establishment, the areas of well-grown herbage plots in the test field increased. The dry weight of standing crops in the well-grown herbage plots was not so significantly different from that in the adjacent control plots established by the ordinary ploughless method.

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The objective of this study was to examine dry matter (DM) productivity and lodging-resistance in multi-cutting green fodder sorghum sprayed with three plant growth regulators (PGRs), namely, gibberellin (GA), cycocel (CCC), and α-naphtyl acetate (NAA). The first crop was harvested at the end of July and the second crop at the middle of September immediately after the attack of a typhoon, respectively. The third crop was harvested at the end of November after the first frost. Direct effects of PGRs were examined in the first and second crops by spraying PGRs and the after-effect of PGRs was examined in the third crop without spraying to it. DM yield was increased by GA and decreased by CCC in the first and second crop. On the contrary, it was decreased by GA and increased by CCC in the third crop. Thus, after-effects of GA and CCC were different from the direct effects of those on DM yield. NAA increased DM yields of three crops. In the first and second crops, leaf area index (LAI) was slightly increased and extinction coefficient (K) was decreased by GA and NAA treatments. The decrease of K was due to the increase of plant height by GA treatment and stem inclining by NAA treatment. Therefore, GA and NAA treatments increased crop growth rate (CGR) in the first and second crops through increasing net assimilation rate (NAR). In the third crop, CGR increased by the after-effect of both CCC and NAA, possibly due to the increase of LAI in CCC plot and due to the increase of LAI and NAR in NAA plot. The former was assumed to be due to the enhancements of the tillering and the leaf area enlargement under cooler temperature. The latter was assumed to be due to the strengthening of apical dominance, which caused a fewer but larger tillers. The lodging resistance under typhoon was increased by NAA treatment. This was assumed to be due to shorter internodal lengths and more nodal root's numbers in NAA plot. Thus, the annual DM yield was increased by both GA and NAA treatments. Especially in a extra plot, sprayed with NAA and grown without cutting at the middle of September, annual DM yield was 1.9 times as much as that in control plot.

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A part of an orchardgrass meadow was tilled lineally (9 cm in width and 16 cm in depth) following injection of cattle slurry corresponding to 161 g N m^<-2> (10-16 cm in depth). In the next spring, seven months later, soils of 0-15 cm in depth (a Brown Lowland soil containing volcanic ash soil) were sampled from plot C (untreated control), plot T (only tilled), plot S (only injected with slurry), and plot ST (injected with slurry, tilled and reseeded with perennial ryegrass). the soils were divided to upper (0-5 cm in depth), middle (5-10 cm) and lower (10-15 cm) layers, and then analyzed to clarify their biological changes. The upper layer of plot C contained considerable amounts of roots and microbial biomass estimated by a direct-count method. In this layer of plot C, the amount of mineralized N was small, while the soil respiration rate was high. The tillage (plots T and ST) removed 10% of treated soils onto the side soils, and further made the soil chemical and biological properties to be relatively homogenous in all layers. Slurry injection (plots S and ST) increased amount of total N by about 20%. In plot S, the soil respiration and N-mineralization rates increased in the upper layer, but not in the middle and lower layers, where a low specific respiration rate (CO_2-C biomass-C^<-1>) was observed. Such repression of soil respiration was not observed in the middle and lower layers of plot ST which was treated by both of slurry injection and tillage. the microbial biomass, the soil respiration rate and the amount of N-mineralization in plot ST increased even in the middle and lower layers. These results show that combination of slurry injection and tillage attained increases in C- and N-mineralization rates, amount of roots, and microbial biomass in all layers.

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Italian ryegrass (IRG) and Rhodesgrass (RG) harvested at the heading stage and the early flowering stage were ensiled in duplicate into 41 capacity experimental laboratory silos. Factors affecting these silage qualities, including moisture content, mechanical treatment, preservation temperature and addition of commercial inoculant (Lactobacillus casei) were investigated. Both materials to be ensiled had high moisture condition, 83 to 85%. The main chemical properties of RG compared to IRG were lower WSC and true protein contents of 4.1% DM and 86.7% total-N, and higher NDF, ADF and hemicellulose. In the IRG silages, wilting laceration and preservation temperature of 5℃ and 36℃ resulted in greatly increased lactic acid and decreased acetic acid and VBN contents compared with the control. Commercial inoculant did not affect the IRG silage. In RG silages, addition of 0.2% commercial inoculant only produced higher content of lactic acid and decreased the pH value compared with the control. Laceration and 36℃ of preservation temperature did not have a substantial effect on the quality of RG silages. The pH value, acetic acid and VBN content of RG silages were higher compared with IRG silages. The present study suggested the need of more detailed researches on these confirmed ensiling nature of tropical forages.

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