• Korean journal of applied entomology
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• v.58 no.4
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• pp.347-354
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• 2019

Temperature-dependent traits of Laodelphax striatellus, rice stripe virus vector, were investigated at 10 constant temperatures (12.5, 15.0, 17.5, 20.0, 22.5, 25.0, 27.5, 30.0, 32.5, and 35.0 ± 1℃) under a fixed photoperiod (14/10-hr light/dark cycle). Unit functions for the oviposition model were estimated and implemented into a population dynamics model using DYMEX. The longevity of L. striatellus adults decreased with increasing temperature (56.0 days at 15.0℃ and 17.7 days at 35.0℃). The highest total fecundity (515.9 eggs/female) was observed at 22.5℃, while the lowest (18.6 eggs/female) was observed at 35.0℃. Adult developmental rates, temperature-dependent fecundity, age-specific mortality rates, and age-specific cumulative oviposition rates were estimated. All unit equations described adult performances of L. striatellus accurately (r² =0.94~0.97). After inoculating adults, the constructed model was tested under pot and field conditions using the rice-plant hopper system. The model output and observed data were similar up to 30 days after inoculation; however, there were large discrepancies between observed and estimated population density after 30 days, especially for 1^st and 2^nd instar nymph densities. Model estimates were one or two nymphal stages faster than was observed. Further refinement of the model created in this study could provide realistic forecasting of this important rice pest.

• Journal of Animal Science and Technology
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• v.45 no.5
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• pp.819-824
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• 2003

Effects of feeding browses on growth and meat quality of Korean native goats were investigated. Twenty eight heads of male goats were divided into four treatment groups fed diets containing oak browse, pine browse, fermented pine browse, and rice straw. Growth rate, feed intake, carcass and meat quality and blood and serum criteria were investigated. The highest average daily gain of goats was 45.3g from oak browse, and goats on pine browse gained similar to those on fermented pine browse. Daily forage intake was 197g DM for oak browse and 74g DM for fermented pine browse. Feed efficiency(g feed/g gain) of oak browse was 11.0g and that of pine browse was 15.1g. From the results of serological inspection, metabolism in body was normal with all the browses tested. Dressing percentage was 45.1~46.2% and meat percentage was 55.2~55.9% without significant differences between diets. Fat percentage of goat carcasses fed rice straw was higher than those fed pine browse or fermented pine browse which was, however, not significantly different from those on oak browse. Shear force and coking loss of goat meat on pine browse or fermented pine browse was less than those on rice straw(p〈0.05) without significant differences between other browses. Juiciness, tenderness, and flavor of the goat meat were the better(p<0.05) from the pine browse diet than from rice straw.

• Journal of Animal Science and Technology
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• v.50 no.3
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• pp.407-416
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• 2008

본 연구는 CaCl2 용액의 주사량이 품종별 암사슴의 뿔 발생 유도에 미치는 영향을 구명하기 위하여 꽃사슴, 레드디어 및 엘크 암컷 각 6두에 대해 30% CaCl2 용액의 주사량을 1ml?, 1.5ml? 및 2ml?의 3처리구로 나누어 전두골 좌, 우 양쪽 골막에 3월과 7월 두 차례 주사한 후 사슴뿔 발생 유도율, 사슴뿔 생산량, 발육성적을 조사하였다. 품종별 암사슴의 뿔 발생은 꽃사슴이 1ml? 처리구의 한 마리 한쪽에서만 발생하였고, 레드디어는 2ml? 처리구의 한 마리 한쪽에서만 유도되어 꽃사슴과 레드디어의 뿔 발생 유도율은 8.3%였다. 엘크 암사슴은 1ml? 처리구에서는 뿔 발생이 일어나지 않았으며, 1.5ml?와 2ml? 처리구에서는 모두 뿔 발생이 유도되어 유도율은 67%였다. 뿔 생산량은 꽃사슴의 경우 길이 21cm?이고 무게 70g 이었으며, 레드디어는 길이 18.5cm?에 무게 83g의 뿔을 생산하였다. 엘크는 3월 1.5ml? 처리구의 길이가 평균 34±3cm?이었고 무게는 526~1,008g이며, 2ml? 처리구는 길이가 평균 39±8cm?, 무게는 693~1,379g의 범위에 있었다. 엘크의 2ml? 처리구는 7월에 주사한 것이 뿔 길이와 뿔 생산량에서 3월의 것보다 적었다. 암사슴 뿔의 발육은 엘크의 경우 주사 후 20일경에 길이 0.5~1cm? 정도의 돌기로 자랐고, 40일까지는 유발된 상처와 함께 1~3cm?정도의 완만한 성장을 보였다. 본격적인 성장은 처리 후 60일경이 지나야 일어났고, 120일경에 절각을 하였을 때 뿔 길이는 28~44cm?의 범위에 있었다. 생산된 암사슴 뿔을 세로로 절단하였을 때 전체 길이의 위쪽 70%는 골화가 되지 않은 상태였다. 암사슴의 뿔 발생 유도는 번식성적에는 전혀 영향을 미치지 않았다. 봄에 처리한 사슴의 재생 뿔 발생은 불규칙하게 일어났고, 재생 뿔 발생률은 평균 45%였으며, 주기가 진행될수록 길이와 생산량은 줄어드는 경향을 보였다. 결론적으로 30% CaCl2 용액의 주사량을 조절하여 처리하면 꽃사슴, 레드디어 및 엘크의 암컷에서 뿔 발생을 유도할 수가 있으며, 엘크 암사슴의 뿔 발생 유도를 위한 최적 주사량은 1.5~2ml? 범위였다.

• Journal of Animal Science and Technology
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• v.50 no.3
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• pp.363-372
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• 2008

To investigate the effects of total mixed ration(TMR) on growth performance and carcass characteristics of Hanwoo steers, sixty steers were randomly assigned to one of four treatment groups; separate feeding of concentrate and rice straw(control), wet TMR(TMRⅠ), dry TMR with 20%(TMRⅡ) and 40%(TMRⅢ) barley bran from 6 to 28 month of age. In growth performance, average daily gains of TMRⅡ group was the highest(0.70kg/day) but significant differences between treatments were not found(p>0.05). Average feed required for kg body weight gain of control group was 11.63kg. Those of TMRⅠ through TMRⅢ were 9.29, 10.46 and 10.71kg, respectively. Dressing percentage and retailed cut percentage were 59% and 63%, without any significant differences between treatments(p>0.05). There were no significant differences in rib-eye area, back fat thickness, meat color and fat color (p>0.05). Average marbling score was higher(p<0.05) in TMRⅠ than in control group.

• Journal of Sericultural and Entomological Science
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• v.14 no.2
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• pp.113-123
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• 1972

The authors studied on the effect of silkworm eggs collected from the whole silkworm egg producers in Korea to know the cocoon crops, and the results are as follows. There was no remarkable correlation on the effect of silkworm eggs quality for the cocoon crops but can be concluded as follows. 1) There was a weak correlation between the hatching ratio and economical hatching ratio but no correlation between economical hatching ratio and cocoon crops. In other word, hatching ratio couldn't be influenced for the silkworm health. 5) Non-hybrid ratio (miss-crossing ratio) influenced to the amount of reelable cocoons and pupation ratio but on this experiment, there was a little influence for the cocoon crops. The authors found that there is no difference between origin and its F$_1$crops under the more suitable conditions. Non-hybrid ratio can be determined the silkworm eggs quality, but notice that the ratio decrease only when used pure origin. 3) There is some correlation between harvesting amounts of reelable cocoon and pupation ratio. In general, the eggs which harvest small amounts of reelable cocoon are lower on the pupation ratio. 4) The influence of cocoon layer ratio is based on the variety absolutely but cocoon crops also has a little influence on the cocoon layer ratio.

• Korean journal of applied entomology
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• v.48 no.3
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• pp.311-318
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• 2009

Nymphal development, adult longevity, and oviposition of six different species of stink bugs were compared on seeds of a soybean cultivar, Taekwangkong, and two mung bean cultivars, Kyungseonnogdu and Jangannogdu in the insect rearing room ($28{\pm}2^{\circ}C$, 16L:8D). Nymphs of six species of stink bugs normally developed on Taekwangkong seed. While nymphs of Riptortus clavatus, Halyomorpha halys, and Dolycoris baccarum developed on seeds of Kyungseonnogdu and Jangannogdu normally, all nymphs of Plautia stali, Piezodorus hybneri and Nezara antennata died after 4th instars on Kyungseonnogdu and after 3rd instars on Jangannogdu. Each instar period tended to be increased as nymphal stages were progressed. Nymphal period was shortest on Taekwangkong seed, followed by Kyungseonnogdu and Jangannogdu, irrelevant to stink bugs species. Emergence rate, adult longevity, and preoviposition period of 6 stink bugs were different depending on the reared seeds. Of 6 different species examined, Riptortus clavatus, Halyomorpha halys, and Dolycoris baccarum which fed on Jangannodu did not emerge, Plautia stali, Piezodorus hybneri, and Nezara antennata which fed on Jangannodu did not oviposit.

• Horticultural Science & Technology
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• v.29 no.5
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• pp.420-432
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• 2011

Population dynamics of greenhouse whitefly, Trialeurodes vaporariorum (Westwood), were modeled and simulated to compare the temperature effects of air and tomato leaf inside greenhouse using DYMEX model simulator (pre-programed module based simulation program developed by CSIRO, Australia). The DYMEX model simulator consisted of temperature dependent development and oviposition modules. The normalized cumulative frequency distributions of the developmental period for immature and oviposition frequency rate and survival rate for adult of greenhouse whitefly were fitted to two-parameter Weibull function. Leaf temperature on reversed side of cherry tomato leafs (Lycopersicon esculentum cv. Koko) was monitored according to three tomato plant positions (top, > 1.6 m above the ground level; middle, 0.9 - 1.2 m; bottom, 0.3 - 0.5 m) using an infrared temperature gun. Air temperature was monitored at same three positions using a Hobo self-contained temperature logger. The leaf temperatures from three plant positions were described as a function of the air temperatures with 3-parameter exponential and sigmoidal models. Data sets of observed air temperature and predicted leaf temperatures were prepared, and incorporated into the DYMEX simulator to compare the effects of air and leaf temperature on population dynamics of greenhouse whitefly. The number of greenhouse whitefly immatures was counted by visual inspection in three tomato plant positions to verify the performance of DYMEX simulation in cherry tomato greenhouse where air and leaf temperatures were monitored. The egg stage of greenhouse whitefly was not counted due to its small size. A significant positive correlation between the observed and the predicted numbers of immature and adults were found when the leaf temperatures were incorporated into DYMEX simulation, but no significant correlation was observed with the air temperatures. This study demonstrated that the population dynamics of greenhouse whitefly was affected greatly by the leaf temperatures, rather than air temperatures, and thus the leaf surface temperature should be considered for management of greenhouse whitefly in cherry tomato grown in greenhouses.

• Journal of Animal Science and Technology
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• v.47 no.5
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• pp.783-788
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• 2005

This study was conducted to investigate the optimal CP level in growing goat kids. Forty male goats were divided into four treatment groups fed diets containing CP 12, 14, 16, and 18% of concentrate feed, and rice straw, respectively. Results are summarized as follows. Average daily gain’s(ADG) of groups fed diets with CP 14% and CP 18% were 84.0 and 83.0g/d each, which were higher than group fed diets with CP 12% grown at 69.2g of ADG(P<0.05). Daily feed intakes of concentrate and rice straw were 590g and 45g each and there was no difference found between treatments. The amounts of feed required for body weight gain(g) were similar in the range of 7.0-7.3 for groups fed diets with CP 14%, 16% or 18%. But the group fed diets with CP 12% required somewhat more feed for gain at 8.8g. Dressing percentage of groups fed diet with CP 12% was 61.7%, which was higher than groups fed diets with CP 14% or CP 18%(P<0.05) but similar to that fed diet with CP 16%. Meat percentage from goats fed diet with CP 16% was 51.7%, which were higher than goats fed diets with CP 12% or CP 14%(P<0.05). Fat deposition of CP 12% group was higher than the other groups(P<0.05). Percentage of bone weight averaged 17.0% without any difference among treatment groups. Shear force and cooking loss, which are physical properties of goat meats, were lower in CP 16% and CP 14% groups than the other two groups. Water holding capacity of goats meats from CP 16% was higher than those from CP 18% group(P<0.05). Results from panel test showed that juiciness of meats from CP 16% group was higher than those from CP 12% group(P<0.05). Meats from CP 16% also was tested to be more tender than meats from the other groups. Results from this work suggest that the optimum crude protein level in growing goat's concentrate is 14-16% and that increase above this level seems not to improve meat production.

• Korean Journal of Veterinary Research
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• v.32 no.1
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• pp.15-24
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• 1992

The effects of CC the ovulatory response, oocyte normality, ovarian steroidogenesis and subsequent embryo developmental potential were examined in PMSG-treated rats. On Days of 25~27 of age, immature female Sprague Dawley rats were treated with three different doses(0.05, 0.1 or 1.0mg /day) of clomiphene citrate or vehicle. The females subsequently received 4IU PMSG on Day 28 and/or 10IU hCG on Day 30, and were killed on Day 31. Some females given 0.1mg CC or vehicle with 4IU PMSG were then mated and killed on Days 2, 3, 4 and 5 of pregnancy. Compared to vehicle(control) group, by increasing the doses of CC, there were a significant decrease in the ovulatory response as judged by both the proportion of rats ovulating and the mean number of oocytes per rat and a marked reduction of ovarian weight. The increasing doses of CC substantially promoted the degeneration(%) of oocytes ovulating in a dose-dependent manner. The CC-mediated inhibitions of the ovulatory response and ovarian weight were oompletely overcome by a subsequent treatment of hCG. Increasing doses of CC resulted in a siginificant elevation of serum estradiol with the decreased levels of progesterone and androgens. The additive treatment with hCG was effective to reduce the elevation of estradiol and to increase the reduction of progesterone produced by high dose(1.0mg) of CC. The preimplantation embryos recovered from 0.1mg CC-treated pregnant rats demonstrated a progressive early loss from Day 3 of pregnancy with a significant increase in the percentage of degeneration during all periods examined, compared to controls. The rate of progressive embryo cleavage in the CC-treated rats were slower than that in controls from Day 3 of pregnancy. Additionally, the percentage of the cleaved embryos recovered from the CC-treated rats remained significantly lower consistently from Day 2 of pregnancy, compared to control regimen. These results demonstrate a possible mechanism of CC-mediated inhibition of ovulatory response in the rats which may include the attenuation or blockade of the endogenous secretion of gonadotropins and also suggest that its detrimental effects observed on oocyte normality and embryonic development may be caused by abnormal follicular steroidogenesis( especially elevated estradiol) preceding fertilization.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.33 no.3
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• pp.248-253
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• 1988

The longer pollen stage grew to flowering stage, the higher anther respiratory rate in vivo became. and it was rapidly increased just before flowering. The anther respiratory rate in vitro showed the first and second peak points after 3-7 days and 9-1l days in culture, respectively, and fastest and highest in Daecheongbyeo with high sporophytic potentiality. It was lower in cold-pretreatment than non-treatment at the early days, but higher from 15 days after culture. The frequency of browning anthers was promoted by cold-pretreatment. The respiratory rate was not different between uncolored and browned anthers at 12 days, but it was higher in browned anthers after 24 days in culture.