• Development and Reproduction
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• v.21 no.3
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• pp.287-295
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• 2017

This study was conducted to observe egg and larvae morphological development of carp to obtain basic data for resource conservation and taxonomic research. Brood carp used in the research (total length 67.3-75.5 cm, average $71.0{\pm}3.45cm$) were bred in a circular rearing aquarium ($600{\times}300{\times}100cm$) using a running water system from January to July, 2015. Breeding water temperature was maintained at $23.0-25.0^{\circ}C$(average $24.0^{\circ}C$). Fertilized carp eggs were translucent and globular, and their size was 1.75-1.89 mm (average $1.82{\pm}0.06mm$). Blastoderms formed 10 min after fertilization and reached the two-cell stage 30 min after fertilization. Then, the embryo turned dark and exhibited melanophores, and blood started flowing from the heart across the egg yolk at 42 hrs and 50 min after fertilization. Hatching began 70 hrs and 26 min after fertilization larvae emerged through the egg membrane, starting from the head. The length of prelarvae immediately after hatching was 5.23-5.38 mm (average $5.31{\pm}0.11mm$) the mouth and anus were closed, and the pectoral fin was formed. Postlarvae at 18 days after hatching had a total length of 11.9-13.9 mm (average $12.9{\pm}1.40mm$), separate anal fin and back membranes, and fin ray. Juveniles fish at 35 days after hatching had a total length of 29.9-30.2 mm (average $30.1{\pm}0.13mm$), with the body covered with scales, and the same number of fin rays, color, and shape as their broodstork.

• Korean Journal of Poultry Science
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• v.27 no.1
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• pp.19-23
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• 2000

The effects of microbial phutase on laying performance and phosphorus utilization were examined at different levels of dietary nonphosphorus(NPP) in 320 23-week-old Hy-line brown hens for 12weeks. Diets were formulated 0.275%(T1), 0.220%(T2), 0.165%(T3) of NPP levels, and supplemental microbial phytase was 300DPU/kg diet constantly. Conventional diet(C) was formulated 0.275% NPP level without microbial phytase. Egg production and egg mass were higher in T2 than the others (p<0.05), and average egg weight was higher in T1 than the other (p<0.05). Egg productivity was tended to increase with supplemental phytase compared to conventional diet. Daily feed intake a hen also increased in T2 (p<0.05). Feed conversion ratio was improved slightly without significant difference. Eggshell breaking strength and thickness were not different significantly among the treatments. Haugh unit and yolk color were also not different. Calcium and phosphorus retention in body increased in T2 (p<0.05), but dry matter and nitrogen retention were not different significantly. Differences in nitrogen and calcium excretions were not found among the treatments. But phosphorus excretion decreased in order of dietary phosphorus levels with supplement phytase compared to C (p<0.05). Tibial ash, calcium and phosphorus were similar among the treatments. In conclusion, supplemental microbial phytase in laying diet may help to utilize phytase phosphorus, and could decrease NPP intake.

• Korean Journal of Veterinary Research
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• v.34 no.3
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• pp.593-599
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• 1994

This study was carried out to investigate the necrotic enteritis of chicken in Korea. Epidemiological, pathological and microbiological examination were done on 12 naturally occurred cases of necrotic enteritis of chicken. And the susceptibility of isolated bacteria to antimicrobial agents was also examined. The results obtained were as follows; 1. The Clostridium perfringens infection, necrotic enteritis of chicken, occurred in the chickens mainly raised in floor pens. Necrotic enteritis of chicken was occurred coincidently with coccidiosis and Gumboro disease frequently. And several cases were recurred at 2-3 weeks after recovery. 2. Clinical signs of the infected chickens were depression, decreased appetite, reluctance to move, diarrhea, ruffled feathers and acute death within several hours. 3. The characteristic biochemical properties of isolates were 2-band hemolysis, no motility, positive reaction of reverse CAMP test and the formation of LV precipitate in egg yolk medium. 4. Gross lesions of the infected chickens were distention of intestine with gas, thickened mucosa and formation of thick pseudomembrane in intestine. Livers were friable with yellowish brown color and, in some case, showed demarcated necrotic foci. 5. Histopathological findings of the infected chickens were severe necrosis of the intestinal mucosa and attachment of numerous large bacilli to the mucosal surface of necrotic villi. In liver, necrosis of liver tissue and numerous large bacilli in the necrotic foci were also observed. 6. In susceptibility test to antimicrobial agents, 12 isolates of Clostridium perfringens were highly sensitive to ampicillin, baytril, cephalothin and penicillin.

• Journal of Embryo Transfer
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• v.28 no.2
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• pp.113-119
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• 2013

The study focuses on the quality assessment of Black Bengal buck semen preserved at chilled condition. In this in vitro trial, collected semen from Black Bengal bucks was preserved at chilling temperature ($4{\sim}5^{\circ}C$) in tris-glucosecitrate yolk medium of 1:5 ratios for four days. Artificial Vagina (AV) method was utilized to collect semen from buck. General evaluation of semen includes the color, mass activity and density were measured by direct visual examination. However, computer-assisted sperm analysis (CASA) and phase contrast microscopy were used to figure out the motility (%), hyper-activated (HYP) motility (%) and number of abnormal spermatozoa (%) initially, and at every 24 h intervals. The result revealed that spermatozoa preserved at chilling temperature showed significantly (P<0.05) lower motility and HYP motility with the progression of preservation. The number of phenotypically abnormal spermatozoa significantly (P<0.05) increased following preservation. Although significant positive correlation (r=0.945; P<0.05) was existed between % motile and % HYP motile spermatozoa however, the % of morphologically abnormal spermatozoa was negatively correlated with % motile (r=-0.997; P<0.05) and % HYP motile spermatozoa (r=-0.946; P<0.01). Therefore, we concluded that the quality of chilled semen progressively losses its viability and doesn't remain useable after certain period of preservation with respect to its motility and morphology.

• Journal of the Korean Professional Engineers Association
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• v.17 no.3
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• pp.22-31
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• 1984

Sardine ant mackerel so called dark muscled fish have been underutilized due to the disadvantages in bloody meat color, high content of fat, and postmortem instability of protein. Recent efforts were made to overcome these defects and develope new types of product such as texturized protein concentrates and dark muscle eliminated minced fish. Approach of this study is based on the rapicl dehydration of foamed fish-starch paste by dielectric heating. In process comminuted sardine meat was washed more than three times by soaking and decanting in chilled water and finally centrifuged. The meat was ground in a stone mortar added with adequate amounts of salt, foaming agent, and other ingredients for aid to elasticity and foam stability. The ground meat paste was extruded in finger shape and heated in a microwave oven to give foamed, expanded, and porous solid structure by dehydration. Dielectric constant ($\varepsilon$′) and dielectric loss ($\varepsilon$") vcalues of sardine meat paste were influenced by wavelength and moisture level. Those values at 100KHz and 15MHz were ranged 2.25∼9.86 ; 2.22∼4.18 for $\varepsilon$′ and 0.24∼19.24 ; 0.16∼1.25 for $\varepsilon$", respectively, at the moisture levels of 4.2∼13.8％. For a formula for fish-starch paste preparation, addition of 20∼30% starch (potato starch) to the weight of fish meat, 2∼4% salt, and 5∼10% soybean protein was adequate to yield 4∼5 folds of expansion in volume when heated. Addition of egg yolk was of benefit to micronize foam size and better crispness. In order to provide better foaming and dehydration, addition of 0.2∼0.5% sodium bicarbonate foaming agent, was proper to result in foam size of 0.5∼0.7mm and foam density of 200∼400/$\textrm{cm}^2$ which gave a good crispness.

• Korean Journal of Poultry Science
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• v.25 no.3
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• pp.119-128
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• 1998

On account of the recent improvement in performance of brown layers, the market share taken by brown layers has increased to about 50% in the world and to almost 100% in Korea. There are several other reasons why the industry has moved from white to brown, such as : brown layers are used to be more robust, more docile and easier to manage ; e brown layers are easier to sex at the hatchery ; brown layers lay less second grade eggs, due to a better shell Quality ; brown eggs seem to be more attractive than white ; and a clear consumer preference, thus a better price per egg. More recently, however, the trend towards brown eggs has been slowing down. The main reasons for this lie in that white layers can still produce an egg at a lower cost and that white eggs have better de-shelling properties, easier candling and higher yolk and solid content of the liquid egg which are benefits for egg processing industry. Although the performance of the brown layers is still improving, there are increasing opinions in the poultry industry that the market portion of white layers should be increased based on the following reasons, such as : shell color has no effect on the nutritive value of eggs ; . brown layers consume more feed ; the percentage of meat spots is significantly higher in brown eggs than in white eggs ; . brown layers are less efficient in the second cycle of production than in the first ; white layers are more resistant to the disease of fowl typhoid. In order to increase the market share of white layers in Korea, it may be needed to enlighten the consumers not to prefer the brown and large eggs and to inform the excellencies of white eggs widely.

• The Korean Journal of Ecology
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• v.1 no.2
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• pp.44-48
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• 1977

The spawning behavior and developmental pattern of the Korean eleotrid fish (Odontobutis obscurus) was investigated in one of the tributary of Han River. The spawining of this species begins on April and continues up to August, whereas, the spawning. of same species were between the end of June and the middle of July in Kyushu, Japan. August The spawning places were the margin of river, its the bottom composed of sand and pebble (Table 5). The velocity of water in the spawning places was 0-40cm/sec, and the depth of waters was 10-40cm. The egg was spawned on underside of stone in the spawning places with one or two folds and ellipsoid in shape, 3.4mm in long diameter and 2.0mm in short diameter. The yolk is 1.2mm in diameter and yellow in color. For hatching of the egg, it takes one month in, $16^{circ}C~19^{\circ}C$ water, in Japan, whereas it takes only 14 days in $20^{circ}C~30^{\circ}C$ wate rin the study area. The growth rate of larva and juvenile fish were as follows: new hatched larva is 45mm in length; after 5 days it became 5.0 to 5.5mm in length and 1.2 to 1.5mm in height after 20 days. it became 11.0mm in length and 2.3mm in length. The mean size of the mature female is 110mm in total length and larger 10mm than that of the same fish found in Japan.

• Restorative Dentistry and Endodontics
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• v.14 no.1
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• pp.173-177
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• 1989

As widely known major cause of tooth discoloration is red blood cell in dentinal tubules after tooth trauma and extirpation. Hemoglobin in the red cells easily conbine with hydrogen sulfide and change natural tooth color into dark brown. To confirm and compare the effect of bleaching agents test material was made as fellows: No. 40 paper points were soaked in blood and put into the oven for 24 hours to dry. Dried paper points were again soaked in diluted yolk by distilled water for a minute and kept the points for a week to get fully sulfide. Hydrogen peroxide (25%), Sodium hypochlorite (2%), Sodium hyposulfate (2%), Sodium perborate and mixture of Hydrogen peroxide (25%) and Sodium perborate were employed as bleaching agents. About 0.2ml of each medicaments were put into the small test tubes and blood soaked paper points were gently placed vertically with the apex downward and kept 24 hours in the oven ($37^{\circ}C$). Every 24 hours the medicaments were renewed at 24 and 48 hours. Following are the results of the study: 1. Significant bleaching effect was found on the case of hydrogen peroxide (25%) after 24 hours. The area above 2mm from apex also fully bleached after 48 hours. 2. A mixture of hydrogen peroxide and sodium perborate treated case showed moderate effect at 24 hours and significant effect at 48 hours. High portion of the point (above 2mm) was bleached satisfactory at 72 hours. 3. The effect of sodium perborate at 48 hours showed moderate and significant at 72 hours. 4. Sodium hypochlorite and sodium hyposulfate were weak agent in bleaching. At 72 hours case revealed moderate effect and influenced on high portion of the point very weak effect.

• Korean Journal of Poultry Science
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• v.15 no.4
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• pp.281-286
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• 1988

This experiment was conducted to determine the optimum level of Red Pepper (including seeds) for laying-hen'diet in summer. A total 240 birds of 37 week-old Manina Brown Hen was alloted to 4 treatments, 3 replications per treatment, according to complecately randomized design to find out the effects of adding levels (0, 0.03, 0.05, 0.08%) of Red Pepper on laying Performance and e99 Quality of experimental birds for 10 weeks. The results obtained from this study were summaried as follows : 1) I班 shell thickness was different significantly among treatments, (P＜0.05). Especially, Ta was highest one. 2) Egg shell breaking strength was highly significant difference between C and $T_1$, $T_2$, $T_3$ (p＜0.01). 3) Yolk color of $T_1$, $T_2$, $T_3$ was higher than C (p＜0.01), but there was no significant difference between treatments. 4) Egg Production was slightly higher with adding Red Pepper, but the differences were no significant. 5) No significant differences were found in average egg weight among treatments.

• Korean Journal of Organic Agriculture
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• v.12 no.2
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• pp.219-230
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• 2004

In recent years, the consumption of livestock products were markedly decreased by awareness of world-widely occurred diseases including mad cow disease, Foot and mouth disease, Hog cholera, and Poultry Influenza virus. the consumers ara also wanting to have highly safe food such as organic animal products because of concerning about residual of antibiotics in animal products. However, disease control and impairment of productivity are the major problem in organic animal production. On these points of view, the present study was undertaken to investigate the effects of 1% or 2% of dietary probiotics fortified with various minerals on improvement of egg production and egg quality in old lay6r feeding low quality feed mainly composed of food waste, sesame meal, and rice bran. After 4 weeks of experimental feeding, the diameter of spreading of egg white was clearly decreased from 11.2cm of control eggs to 10.5m and 10.1m in 1% and 2% treatment group eggs, respectively. The color of egg yolk was 9.3 in control eggs but remarkably increased in treatment groups showing 10.1~10.2. Egg production was 75.8% in control layers but significantly increased to 79.8% of 1% treatment group and 82.9% of 2% treatment group layers. Egg weights (C : 66.3g, 1% : 73.2g, and 2% : 76.7g) and egg shell thickness (C : 0.33mm, 1% : 0.35mm and 2% : 0.36mm) were also increased by the addition of 1% or 2% of probiotics when compared to those of control group eggs. All together, it has been suggested that dietary addition of probiotics fortified with various minerals can improve the egg quality and egg production in layer's productivities by the recycling of organic waste resources such as food waste and agricultural by-products.