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To investigate seasonal variations in the digestive functions of sika deer, five female sika deer were provided with an amount of alfalfa hay cubes equivalent to voluntary food intake during winter. We measured the rate at which the food passed through the digestive tract, digestibility and rumen fermentation during the summer (August), autumn (November), winter (February) and spring (May). Total mean retention time in the digestive tract during summer and autumn was numerically longer than that in winter and spring, but the difference did not reach significance. Organic matter and fiber were less digestible in summer and autumn than in winter and spring (P < 0.05), whereas the digestibility of the dry matter tended to vary with the seasons (P < 0.1). Ruminal pH values seasonally changed (P < 0.01), and were the lowest in autumn. The concentration of ruminal ammonia‐nitrogen differed significantly among the seasons (P < 0.05), increasing in winter and decreasing during spring and summer. The numbers of protozoa changed significantly among the seasons (P < 0.05), being higher in autumn than in winter and spring, and intermediate in summer. The concentration of total volatile fatty acids was not seasonally affected, but the molar percentages of propionic acid and butyric acid significantly changed according to season (P < 0.05 and P < 0.01, respectively), and the ratio of acetic to propionic acid tended to change with the seasons (P < 0.1). The results of this study suggested that the digestive functions in sika deer, fed a commercial diet at a restricted level, differed notably among the seasons and these variations might partially be due to environmental effects.  相似文献   
3.
Effects of β‐cyclodextrin diallyl maleate (CD‐M) on methane production, ruminal fermentation and digestibility were studied both in vitro and in vivo. In in vitro study, diluted ruminal fluid (30 mL) was incubated anaerobically at 38°C for 6 and 24 h with or without CD‐M using hay plus concentrate (1.5:1) as a substrate. The CD‐M was added at different concentrations (0, 1.25, 2.5, 5.0 and 7.5 g/L). The pH of the medium and numbers of protozoa were not affected by the addition of CD‐M. Total volatile fatty acids were increased and ammonia‐N was decreased, molar proportion of acetate was decreased and propionate was increased (P < 0.05) by CD‐M. Methane was inhibited (P < 0.05) by 14–76%. The effect of CD‐M on methane production and ruminal fermentation was further investigated in vivo using four Holstein steers in a cross‐over design. The steers were fed Sudangrass hay and concentrate mixture (1.5:1) with or without CD‐M (2% of feed dry matter) as a supplement. Ruminal proportion of acetate tended to decrease and that of propionate was increased (P < 0.05) 2 h after CD‐M dosing. Total viable counts, cellulolytic, sulfate reducing, acetogenic bacteria and protozoa were unaffected while methanogenic bacteria were decreased (P < 0.05) by CD‐M. The plasma concentration of glucose was increased, whereas that of urea‐N was decreased (P < 0.05). Methane was inhibited (P < 0.05) from 36.4 to 30.1 L/kg dry matter intake by the addition of CD‐M. Apparent digestibilities of dry matter and neutral detergent fiber were not affected while that of crude protein was increased (P < 0.05) in the medicated steers. These data suggested that dietary supplementation of CD‐M decreased methane production and improved nutrient use.  相似文献   
4.
For the development of effective procedures to control invasive plants, it is necessary to learn about their mechanism of spread, for which an understanding of the plant's genetic variation may be important. Sicyos angulatus is a widespread and invasive weed that grows among forage crops and natural vegetation in Japan. Inter-simple sequence repeat (ISSR) genotyping was used to detect the regional patterns of genetic variation of S. angulatus in its introduced range in Japan. The goal of this research was to assess the introduction dynamics and mechanism of spread of S. angulatus in Japan. Four screened ISSR primers produced 15 reliable bands, and 12 of these were polymorphic among six areas in central and north-eastern Japan. The analysis of molecular variance ( amova ) revealed that 88.4% of genetic variation occurred within areas rather than between the two regions (1.1%), or among areas within regions (10.5%). While the total gene diversity among areas ( Ht ) was 0.1684, the coefficient of gene differentiation was low among two geographically distinct regions ( Gst = 0.053). The genetic diversity indices ( h  = 0.116; I  = 0.173) of the Fuji river area, assumed to be near the first introduction site, were not higher than other areas (total h  = 0.165; total I  = 0.263). In contrast, those of the Chikuma river and Tenryu river areas were relatively high ( h  = 0.173 and 0.187; I  = 0.276 and 0.277 respectively). The Mantel test showed no significant correlation between geographical and genetic distances. These results suggest multiple introductions from the same gene pools into both central and north-eastern regions of Japan.  相似文献   
5.
ABSTRACT: To reveal the ontogeny of pancreatic exocrine function in the early larval stage of eel, cDNAs encoding major pancreatic enzymes, trypsinogen, amylase and lipase were identified from the Japanese eel Anguilla japonica and their expression pattern in larvae was analyzed. The cloned eel trypsinogen precursor consisted of 224 amino acids and showed 82.2% identity to trypsinogen-2 of winter flounder Pleuronectes americanus . The eel amylase precursor consisted of 512 amino acids and showed 77% identity to winter flounder amylase. Eel pancreatic lipase was composed of 470 amino acids and had 58.3% of identity to human pancreatic lipase. In the eel larvae, mRNA expression of trypsinogen and amylase was first detected at 6 days post-hatching (d.p.h.), and the expression level increased between 7 and 8 d.p.h. In contrast, mRNA expression of lipase was first detected at 8 d.p.h. Eel larvae start to feed actively at 8 d.p.h. Thus, it was indicated that eel pancreas starts to synthesize digestive enzymes at 6 d.p.h. and acquires full function by the onset of exogenous feeding at 8 d.p.h.  相似文献   
6.
The source of the velvetleaf spreading its distribution rapidly and causing serious problems in forage fields all over Japan since the mid 1980s was thought to be a new accidental introduction of seeds from velvetleaf mingled in some imported grains from the USA and Australia. However, velvetleaf used to be cultivated as a fiber crop until the 1880s. We examined the intraspecies variations, such as morphological characteristics and growth habits, using accessions previously collected and obtained from imported grains. Using principal component analysis (PCA), the accessions were classified into crop type and weed type. The crop type capsule was mostly an ivory color, and the weed type was mostly an ebony color. The crop type showed characteristics of a fiber crop, such as an erect form, uniform flowering and a low seed dormancy rate. Conversely, the imported grains were classified into the weed type which showed a strong weedy nature, such as branched form, long flowering period, high reproductive ability and a high dormancy rate. These results suggest that the new introduction is different from the indigenous fiber crop, and may possibly be the source of the present invasive velvetleaf because of its strong weedy nature. However, further studies comparing the new introduction directly with the present velvetleaf are necessary.  相似文献   
7.
Five female sika deer and three male Holstein cattle were offered alfalfa hay cubes at 2% (deer) and 2.5% (cattle) of bodyweight, respectively. The passage rate through the digestive tract, digestibility and rumen fermentation of the animals were determined. The rate of ruminal passage was higher and the total mean retention time in the digestive tract was shorter in deer than in cattle. In addition, the rate of post‐ruminal passage in deer was lower. The digestibilities of dry matter, organic matter, crude protein and fiber in deer were significantly lower than in cattle (P < 0.05). The concentration of total volatile fatty acids in the rumen was significantly higher in deer than in cattle. The molar percentage of acetic acid was lower and that of valeric acid was higher in deer (P < 0.05). The number of protozoa was somewhat higher in deer. These results suggested that the lower digestibility in deer might be a result of the shorter retention time in the digestive tract.  相似文献   
8.
Four female Sika deer (mean bodyweight, 48 kg) and three male Holstein cattle (mean bodyweight, 209 kg) were offered alfalfa hay cubes at 2% (deer) and 2.5% (cattle) of bodyweight, respectively. The digestibility of the cell walls and cell wall components (rhamnose, arabinose, xylose, mannose, galactose and glucose) in alfalfa and its retention time of the alfalfa in the digestive tract and rumen parameters were determined. Cell walls and xylose were less digestible in the deer than in the cattle (P < 0.01 and P < 0.05, respectively). The digestibility of galactose in the deer was as high as that in the cattle. The digestibility of the other sugars and total neutral sugars was numerically lower in the deer, but the differences were not significant. In the deer, mannose was most digestible, followed in order by galactose, arabinose, glucose, rhamnose and xylose; whereas, in the cattle, mannose was most digestible, followed in order by arabinose, glucose, galactose, rhamnose and xylose. The retention time in the digestive tract was shorter in the deer than in the cattle. In the deer, the number of ruminal protozoa was somewhat higher, and the concentrations of propionic acid and butyric acid were higher (P < 0.05) than in the cattle. These results indicate that Sika deer might utilize pectic polysaccharides as a carbon source in preference to glucose containing polysaccharides such as cellulose. The lower digestibility of all cell wall components except galactose in the Sika deer might be mainly due to its shorter retention time.  相似文献   
9.
Velvetleaf seeds have been found in imported grains in Japan. The plants from these seeds show a weedy growth habit, such as that seen in the noxious velvetleaf which has recently emerged in Japan and noted in our previous study. To elucidate the genetic background of the velvetleaf strains found in imported grains we evaluated the genetic variation of six strains and an additional 39 worldwide velvetleaf accessions using the intersimple sequence repeat (ISSR) polymorphism. Cluster analysis based on the ISSR polymorphism emitted two major clusters which corresponded well with classification by growth habit, that is, crop type and weed type. Five of the six strains from the imported grains formed a small cluster. All six strains united into one major cluster containing the weed type accessions, while all of the old Japanese accessions formed another major cluster containing the crop type accessions. The genetic difference between imported weedy velvetleaf and old Japanese accessions suggests that imported velvetleaves are the source of the recent outbreak of the noxious velvetleaf in Japan.  相似文献   
10.
ABSTRACT:   The fatty acid composition in horse mackerel caught off Nagasaki, off Tsushima Island, and in the middle of the East China Sea was investigated. The ratios of monoenoic and polyenoic acids to the total fatty acids in the Nagasaki and bull trawl catch specimens had a negative correlation. The docosahexaenoic acid (DHA; 22:6n-3) ratios of total fatty acids in summer-caught specimens were lower than those in winter-caught specimens, and this tendency was significantly clearer in smaller-sized fish, while DHA levels in tissues varied little throughout the year. Consistently high levels of DHA were found in various fishing areas, which suggests that horse mackerel offers a stable source of DHA.  相似文献   
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