• Korean Journal of Environmental Agriculture
• /
• v.13 no.2
• /
• pp.209-215
• /
• 1994

Absorption, translocation, and metabolism of the herbicide alachlor in soybean, Chinese cabbage, and barnyard grass seedlings were examined and compared with each other using [phenyl-U-$^{14}C$] alachlor in search of a primary factor contributing to the selectivity of alachlor. When root of each seedling was immersed into the solution containing [$^{14}C$]alachlor, the amount of absorbed radioactivity/mg dry matter of seedling which was suggested to be correlated with the susceptibility of plants to alachlor decreased in the order of soybean ${\gg}$ Chinese cabbage ${\geq}$ barnyard grass and the rate of translocation to shoot was Chinese cabbage ${\geq}$ barnyard grass ${\gg}$ soybean. These orders did not consistently explain the selective phytotoxicity of alachlor. Analyses of extracts by reverse phase chromatography showed that alachlor was detoxified by conjugation with glutathione in all three plants and the rate of glutathione conjugation of soybean, the resistant species to alachlor, was the greatest, while that of barnyard grass, the susceptible, was the lowest among three plants. This result explained well the selective phytotoxicity of alachlor. Both absorption and translocation contribute undoubtedly to the selectivity by influencing the active internal concentration of alachlor. However, neither of them appeared to be a primary factor. It was concluded that the most important primary factor was the rate of glutathione conjugation, which detoxifies alachlor and plays an important role in selectivity.

• Asian-Australasian Journal of Animal Sciences
• /
• v.14 no.1
• /
• pp.41-47
• /
• 2001

Ruminal degradation characteristics of dry matter (DM), neutral detergent fiber (NDF) and crude protein (CP) in fresh leaves of two Japanese native grasses (Zoysia japonica and Miscanthus sinensis) and one sown temperate grass (Dactylis glomerata) were investigated by an in sacco method in spring (mid-May), summer (mid-July) and autumn (mid-September). Japanese native grasses had higher NDF and lower CP concentrations than D. glomerata, and the CP concentration in native grasses decreased in autumn. Ruminal degradability of DM, NDF and CP was lower in native grasses than in D. glomerata (p<0.05) in all seasons. DM and NDF degradability decreased in summer for Z. japonica and D. glomerata, while it decreased in autumn for M. sinensis. CP degradability in Z. japonica was constant throughout the seasons, whereas that in M. sinensis greatly decreased in summer and autumn (p<0.05). It was concluded that Z. japonica could stably supply ruminally digestible nutrients for grazing animals in Japanese native pasture. However, the degradation characteristics of freshly chopped native grasses did not fit the exponential model of $D=a+b(1-e^{-ct})$ proposed by Ørskov and McDonald.

• Asian-Australasian Journal of Animal Sciences
• /
• v.12 no.8
• /
• pp.1215-1221
• /
• 1999

Twelve rumen fistulated cross-bred calves were divided into three groups and fed wheat straw and concentrate mixture according to their maintenance requirement. Animals in group II and III were fed 50 and 100mg rumensin per day, in addition to basal feed. Supplementation of rumensin in the diet decreased the dry matter intake significantly (p<0.05) along with a significant decrease in the straw intake. Digestibility coefficients of all the nutrients were not affected significantly except that of CF digestibility which was lower (p<0.05) in groups II and III as compared to group I. Among N-parameters in the rumen fluid, mean $NH_3-N$ was significantly lower in groups II and III (19.13 and 18.63 mg N/100 ml respectively) than in group I (22.68); total-N and TCA-ppt-N did not differ among the three groups. Total VFA concentration did also not differ among the three groups, however, propionate increased from 24.33 molar % to 32.73 while acetate and butyrate decreased respectively from 65.85 to 58.81% and 9.79 to 8.46%. Total VFA, bacteria and protozoa production rates were not affected significantly due to rumensin in diet. Methane production per kg DDM as well as % of methane in total gas were reduced at both the levels of rumensin on different concentrate ratios with wheat straw as roughage. Similar trend was also observed with rice straw and concentrate mixture as substrate with rumensin addition.

• The Korean Journal of Ecology
• /
• v.28 no.3
• /
• pp.121-127
• /
• 2005

To reveal vegetation history and environmental changes in Mt. Jiri, sediment cores were collected from Wangdeungjae moor of Mt. Jiri. Overall dry matter accumulation rates and sedimentation rates by $^{14}C-dating$ were 0.027 $kg{\cdot}m^{-2}{\cdot}yr^{-1}$ and 0.184 mm/yr since 1250 ($760{\pm}40$ yrs BP, 14 cm in depth). There are three pollen zones; the first zone is below 14 cm depth where Quercus dominated, the second zone is from 14 cm to 6 cm depth where Gramineae increased and Quercus and Salix dominated and the third zone is from 6 cm depth to the top where Pinus and Quercus dominated. Total pollen concentration gradually increased from bottom to the top of sediment core, which implies wet, anaerobic and cool condition during covered period by the core. Calcium and magnesium contents had increased since 14 cm depth, with peaks at 13 and 20 cm depths. This indicates that groundwater had recently become relatively more important than surface water as water source of Wangdeungjae moor Exotic plant or Chenopodiacea pollen was less than 1%. There was little variation in total N and P contents along the length of the core. These results support that Wangdeungjae moor has been little affected by anthropogenic activities. Also, nutrients and heavy metal contents indicate the baseline condition of Wangdeungjae moor.

• Asian-Australasian Journal of Animal Sciences
• /
• v.3 no.3
• /
• pp.247-252
• /
• 1990

Nine Holstein cows in mid lactation period were utilized to examine the effect of recombinant bovine somatotropin (BST) of tow companies (Company A, Company B) on milk production and milk composition under the feeding conditions of Korea. Treatments were 0 (Control), 25 mg BST/day from company A (BST A) and 25 mg BST/day from company B (BST B) injected subcutaneously, once daily beginning at $200{\pm}20$ days postpartum and continuing for 28 days. Cows were fed ad libitum a total mixed diet throughout the experimental period. BST treatments increased average 4% fat corrected milk yields and milk energy output over the 28-day treatment period. However, no differences were observed in dry matter intake, gross efficiency, energy intake and percent milk energy. Although there was a tendency for increased milk fat percent, there were no differences in milk composition and yields of major milk components except for milk fat yield with BST injection. Somatic cells of all groups were also characteristic of a well managed herd. Neither mean body condition score nor body weight was significantly (p <0.05) changed before and during BST treatment. BST concentration in milk remained in the range of control animals throughout the experimental period of BST treatment. Results indicate that short-term injection of recombinant bovine somatotropin from two companies to lactating dairy cow resulted in similar increased in milk yield without alteration of major milk components or feed intake.

• Asian-Australasian Journal of Animal Sciences
• /
• v.14 no.4
• /
• pp.501-506
• /
• 2001

This experiment was conducted to evaluate the effects of supplemental unsaturated fatty acids (UFA) on fermentation characteristics, especially on gas production, cellulose degradation and volatile fatty acid (VFA) concentration by mixed ruminal microorganisms. In order to attain this objective, unsaturated fatty acids including oleic acid (C 18:1), linoleic acid (C18:2) and arachidonic acid (C22:4) were added at varying level. Mixed ruminal microbes used in this experiment were obtained from the rumen of a cannulated Holstein cow. Medium pH values after 7 d incubation were significantly affected by type and level of unsaturated fatty acids (p<0.01). All of UFA inhibited total gas production, and especially treatment of arachidonic acid at the levels of 0.01% gave the lowest gas. production after 7 d incubation (p<0.01). Comparison of the population of protozoa revealed that UFA did not have any significant effect on the total protozoa number. The addition of UFA did not effect dry matter degradation. Volatile fatty acid (VFA) composition of the culture was influenced little by UFA, although the considerable amount of iso-type VFA were detected in UFA supplemented incubations. The ratio of acetic acids to propionic acids, however, was lower than control in all the treatments after 7 d incubation (p<0.01).

• Asian-Australasian Journal of Animal Sciences
• /
• v.17 no.7
• /
• pp.942-946
• /
• 2004

This study aimed to examine the fermentation quality of a tropical Elephant grass (Pennisetum purpuereum) and temperate Italian ryegrass (Lolium multiflorum) forages ensiled additive of fermented juice of epiphytic lactic acid bacteria (LAB) and to determine what factor affects the fermentation characteristics of the crops. In both species cell walls neutral detergent fiber (NDF) and acid detergent fiber (ADF) contents in silages were consistently decreased (p<0.05) with the addition of FJLB at ensiling more then Control treatment. The FJLB additive increased number of LAB (cfu) and lactate concentration in the silages in both species. The Control treatment without additive underwent a clostridial type of fermentation with traces of propionic, iso-butyric, n-butyric acids contents with higher (p<0.01) levels of volatile basic nitrogen (VBN %TN) and had appreciable decreased of nutrient in silages. FJLB treatment improved silage nutritive value with little contents of VBN %TN, ethanol and very small amount of dry matter (DM) and hemicellulose losses (p<0.05) between 2 to 5% and 7 to 3% respectively, in Elephant grass and Italian ryegrass species. The results in this study indicates that while among the factors affecting silage fermentation butyric type of fermentation was more pronounced in tropical elephant grass compared to the temperate Italian ryegrass, FJLB additive revealed a better silage fermentation products in both species.

• Asian-Australasian Journal of Animal Sciences
• /
• v.15 no.6
• /
• pp.834-837
• /
• 2002

The effect of undecorticated sunflower cake (USFC) as critical protein supplement was assessed and compared with deoiled groundnut cake (DGNC) in adult goats and sheep. The animals were fed a basal diet of wheat straw ad libitum and supplemented with either USFC or DGNC to meet their protein requirement for maintenance. Total dry-matter intake by sheep and goats (g/kg $BW^{0.75}$) on USFC was similar to their counterparts on DGNC supplemented group. However, while intake of cake moiety was significantly (p<0.05) higher in USFC, the intake of wheat straw was significantly (p<0.05) higher by animals on DGNC. Digestibility of various nutrients, except lower crude protein digestibility by goats in USFC group, did not differ significantly between animals given DGNC or USFC. DCP and TDN concentration (% DM) was comparable in sheep and goats irrespective of dietary supplement. Similarly, the intake (g/kg $W^{0.75}$) of DCP, DDM, DOM, and TDN was similar between DGNC and USFC in both sheep and goats. It may be concluded that undecorticated sunflower cake is comparable to deoiled groundnut cake as a critical protein supplement to the roughage based diet of small ruminants.

• Asian-Australasian Journal of Animal Sciences
• /
• v.5 no.2
• /
• pp.369-374
• /
• 1992

In order to determine the effect of dietary cellulose levels on chick performance, 1-week-old White Leghorn male chicks were fed semi-purified diets containing either 5%, 10%, 15% or 20% cellulose for 3 weeks. All diets were iso-nitrogenous and iso-caloric. Feed intake and body weight were increased as the cellulose level was increased. Feed conversion was lower in the 5% cellulose diet than in the other diets. Compared to the case of 10% to 20% cellulose diets, relative length (per 100 g body weight) of esophagus, duodenum, small intestine and cecum was longer, and relative weight of esophagus, duodenum and crop was also heavier in the chicks fed the 5% cellulose diet. The other internal organs were not affected by the cellulose level. The retention rates of dry matter and nitrogen were lower in the 5% cellulose group than in the other groups. Concentration of carcass phospholipids was higher in the 5% cellulose group, and that of carcass cholesterol was increased as the cellulose level increased. In conclusion, the dietary cellulose level should be more than 5% to give an adequate chick performance, and no ill effect was found even at 20% level.

• Journal of the korean society of oceanography
• /
• v.32 no.3
• /
• pp.156-161
• /
• 1997

The biogeochemical cycle of silver has rarely been reviewed, even though the silver ion (Ag$^{\times}$) is extremly toxic to some organisms. Its concentration is still rising sharply because of increased anthropogenic activity, specifically the discharge from the film industry (mainly, silver thiosulfate: Ag (S$_2$O$_3$)${^3-}_2$). Recently, a number of researchers have quantified the major fluxes and reservoirs of silver in the open ocean, bays, and estuaries. A review of the available information for Ag cycling in the open ocean shows that the riverine input (from human activity and weathering processes: 7${\times}$10$^6$ kg/yr and 5${\times}$10$^6$ kg/yr, respectively) is the dominant source of Ag to estuarine and coastal regions. Most of the silver (90% of riverine input silver) is removed in coastal sediments by the physical-chemical character of silver due to its high partitioning with particulate matter. On the other hand, in the open ocean the atmospheric input (wet and dry deposition: 1.48${\times}$10$^6$ kg/yr and 1.94${\times}$ 10$^5$ kg/yr, respectively) becomes more important as a source of silver than riverine input. The residence time of silver calculated from available data is 1250 yrs in the deep ocean below 500 m, but only 3 yrs in the surface ocean.