• 한국육종학회지
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• 제41권4호
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• pp.496-501
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• 2009

저장조건을 달리한 딸기 화분을 FCR Test와 결실률을 바탕으로 하여 화분 활력을 조사하고 암술 주두 활력을 인공수분을 통하여 구명함으로서 딸기 교배 육종시 효율성을 높이고자 하였다. '설향'을 대상으로 화분 활력을 조사하였으며 암술 주두의 수정 능력은 '매향' 등 4품종을 공시하고 화분친은 '설향'을 사용하였다. 딸기 화분은 상대습도 33%이하의 건조한 조건에서는 처리 온도($18^{\circ}C$ 및 $22^{\circ}C$)와 관계없이 수일 동안 높은 활력을 유지하였다. 반면 상대습도가 높을수록 화분 활력의 감소가 컸으며 저장한지 7일차에 대부분의 화분이 활력을 상실하여 결실률이 급격히 감소하였고 이러한 경향은 $18^{\circ}C$보다 $22^{\circ}C$저장 조건에서 결실률이 더욱 불량하였다. 즉, 상대습도가 낮은 경우 화분 활력은 크게 감소하지 않았으며, 온도보다는 습도가 화분 활력을 결정하는 중요한 요인으로 작용하는 것으로 판단된다. 암술의 수정 능력은 품종간의 차이가 있었으나 시설 내부 일평균온도가 $15^{\circ}C$내외일때, 제웅 후 2일차부터 8일차까지 평균 77.2%이상으로 높게 유지되었다. 그러나 결실률은 제웅 후 10일차부터 점차 감소하기 시작하여 12일차 이후에는 일부 품종을 제외하고 급격히 감소하였다. 적산온도를 기준으로 하였을 때, 제웅 후 $45{\sim}140^{\circ}C$내외 범위에서 인공수분을 하는 것이 딸기 결실률을 향상 시킬 수 있을 것으로 판단된다.

• Journal of Ecology and Environment
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• 제35권1호
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• pp.9-14
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• 2012

Yellow bitterns (Ixobrychus sinensis) are a small wetland bird common to Asian countries including South Korea, Japan, and China. The aim of this study is to describe diet of yellow bitterns during the breeding season in artificial wetland of northeastern South Korea between May to August 1999-2001. For the purposes of this paper, we observe the frequency of nest visiting by parents during the chick rearing period. A total of 98 boluses regurgitated by 52 chicks aged 1 day to 11 days after hatching form the sample and are shown to contain 323 food items. A bolus contained mean 3.8 items and weighs 0.2 g to 7.7 g. The most regularly occurring food items recorded are fish (63%) and insets (33%). In terms of fish, top mouth minnows (Pseudorasbora parva) and crucian carps (Carassius auratus) are frequently observed. In terms of insects, there are mosquitoes (Diptera), instars of dragonfly (Libelluidae), damselflies (Coenagrinonidae) and water bugs (Diplonychus japonicus). Yellow bitterns were also shown to feed on bull frogs (Rana catesbeiana), shrimp (Palaemonidae), and spiders (Araneae). The size of fish in a bolus ranged from 15.56 mm to 93.73 mm (mean, 37.08 mm). The amount of food can be observed to increase with the age of chicks (r = 0.279, P = 0.025, N = 64) but parents did not provide larger fish as chicks grew. Parent birds visited nests more frequently when they have a larger brood ($F_{1,21}$ = 14.529, P = 0.001). Our results suggest that fish is the most important prey during the breeding season and that age of chicks is related to amount of diet in yellow bitterns.

• Asian-Australasian Journal of Animal Sciences
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• 제25권2호
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• pp.189-193
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• 2012

This experiment was conducted to study variations of serum testosterone and seminal characteristics of Markhoz male goats. Blood samples were obtained via jugular vein, and semen was collected by using an artificial vagina from 14 fertile male goats (2-3 years of age), at 15-day intervals starting on 15 July and ending on 30 October 2010 (during breeding and non-breeding season). Semen volume, total sperm (volume${\times}$concentration), live sperm (%), abnormal sperm (%) and semen pH were significantly superior during the late summer and early autumn (breeding season). Variation of sperm density, motility and progressive motility was not significant during the sampling period. The results presented show that the lowest and highest levels of lactate dehydrogenase in the seminal plasma were recorded in late October (2.82 U/ml) and in late August (4.81 U/ml), respectively. Moreover, the study indicated that the serum testosterone concentration was higher during late summer and early autumn (p<0.05) than at any other of sampling period. There were negative correlations between volume and sperm density (-0.135, p<0.05), and positive correlations between volume and percentage live sperm (0.224) and percentage progressive motility (0.194, p<0.01). Sperm density was correlated with live sperm (0.200, p<0.05) and progressive motility (0.202, p<0.01). The correlation between live sperm and progressive motility was 0.554 (p<0.01). Furthermore, the results in this study indicated a significant positive correlation between live sperm and LDH (0.450) and a negative correlation between sperm density and LDH concentration (-0.272) (p<0.01). Significant, but positive correlations were found between sperm motility and LDH (0.542) and testosterone concentration (0.522), respectively (p<0.05). In conclusion, this study demonstrated that the best obtained semen was collected in late summer (during decreasing photoperiod) and early autumn (September and October). This also coincides with the natural breeding season of Markhoz goats in Iran.

• Asian-Australasian Journal of Animal Sciences
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• 제16권3호
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• pp.353-358
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• 2003

Regarding the fattening of younger cattle that the Ministry of Agriculture Forestry and Fisheries (MAFF) recommends in Japan, this study looked at vitamin A control in feed and blood and its effect on performance of production and carcass composition of Wagyu steers. Five sets from 10 Wagyu artificial identical twins were divided to into 2 groups, a restricted group (Test) and a supplied group (Control). The body weight at the finishing time of the Test was significantly lower than that of the Control (p<0.05). The daily gain from 13 to 21 months old, as the animals in the Test were fed the concentrated feed without Vitamin A, was significantly different (p<0.05) between the Test and the Control. The total daily gains for the Test and the Control for the fattening period were 0.82 kg/day and 0.93 kg/day, respectively, which showed a significant difference (p<0.01). Regarding the rib thickness, the Test was thinner than the Control. The Beef Marbling Scores of the Test and Control were 3.60 and 2.80, respectively. The muscle weight of the Test was significantly smaller than that of the Control (p<0.01). However, regarding the ratio to the carcass, the Test was significantly higher than the Control (p<0.05). For the fat weight, the Test was smaller by about 15 kg than the Control (p<0.01). Furthermore, for the fat ratio to the carcass, the Test was significantly lower than the Control (p<0.05). The bone weights of the two groups were approximately the same. Regarding the ratio of bone to carcass, the Test was higher than the Control (p<0.01). For the younger fattening method, the low level vitamin A in the serum had the effect that the muscle ratio to the carcass weight was greater and the fat was less, but the carcass and muscle weight were less.

• 한국동물생명공학회지
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• 제38권4호
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• pp.215-224
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• 2023

Background: Reproductive management practices play crucial roles to maximize the reproductive performance of cows, and thus contribute to farm profitability. We aimed to assess the reproductive management of cows currently practiced in the dairy farms in an urban farming system. Methods: A total of 62 dairy farms were randomly selected considering all size of farms such as small (1-5 cattle), medium (6-20 cattle) and large farms (> 20 cattle) from selected areas of Dhaka city in Bangladesh. The reproductive management-related parameters viz. estrus detection, breeding method, pregnancy diagnosis, dry cow and parturition management, vaccination and treatment of reproductive problems etc. were obtained in a pre-defined questionnaire during the farm visit. Results: The visual observation method was only used (100.0%; 62/62) for estrus detection irrespective of size of the farms; while farmers observed cows for estrus 4-5 times a day, but only for 20-60 seconds each time. Regardless of farm size, 89.0% (55/62) farms used artificial insemination (AI) for breeding the cows. Intriguingly, all farms (100.0%) routinely checked the cows for pregnancy at 35-40 days post-breeding using rectal palpation technique by registered veterinarian. However, only 6.5% (4/62) farms practiced dry cow management. Notably, all farms (100.0%) provided nutritional supplements (Vit D, Ca and P) during late gestation. However, proper hygiene and cleanliness during parturition was not practiced in 77.4% (48/62) farms; even though 96.7% (60/62) farms treated cows by registered veterinarian for parturition-related problems. Conclusions: While farmers used AI service for breeding and timely check their cows for pregnancy; however, they need to increase observation time (30 minutes/ observation, twice in a day: early morning and early night) for estrus detection, consider dry cow management and ensure hygienic parturition for maximizing production.

• 한국수정란이식학회지
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• 제8권1호
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• pp.21-24
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• 1993

This study was carried out to investigate the effects of imported 0.25 ml straw frozen semen on fertilizing capacity after artificial insemination. A total of 57 ewes of Corriedale were inseminated at the Namwon Branch, National Anirnal Breeding Institute. Lambing percentage and twinning percentage were 12.3% and 114. 3%, resepectively. Average weight at birth and weaning of 120 days old were 4.5kg and 21.9 kg, respectively. Gestation period was 152.6 days.

• 한국발생생물학회:학술대회논문집
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• 한국발생생물학회 1998년도 제4차 학술발표대회 및 정기총회
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• pp.61-62
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• 1998

The effects of rearing temperature on the sex determination of zebrafish were examined to address the questions, "Is it possible to control phenotypic sex artificially; and what genes may be involved in that process\ulcorner". At higher temperature(${32-34}^{\circ}C vs 28.5^{\circ}$C), a dramatic shift of the sex ratio(female 1 : male 9) was found. with DD-PCR cloning, several candidate genes were cloned and analyzed. Further analysis should help to understand sex-determining mechanisms involved in the artificial induction.induction.

• 한국수정란이식학회지
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• 제24권4호
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• pp.293-295
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• 2009

Two postmortem male and female reticulated giraffes were examined. The adult male giraffe showed sigmoid flexure of penis similar to most ungulates. Epididymis was well-developed and divided with head, body and tail parts. On the tip of penis, there was a urethral process. At the necropsy of a 20-month-old and nulliparous giraffe, ovaries, oviducts, two uterine horns with a septum and a cervix were distinctively shown. Understanding reproductive organs of giraffes would be beneficial to succeed in artificial breeding on this species especially in the difficult situation of importing hoofed animals.

• 한국잠사곤충학회지
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• 제36권2호
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• pp.115-118
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• 1994

뽕잎분말이 포함되어 있지 않은 MP-O 인공사료에 대한 누에의 섭식성의 유전현상을 구명하기 위하여 품종간의 섭식성의 차이와 그 유전양시겡 관하여 실험하였다. 280개 보존누에품종 및 71개 육종계통에 대해 섭식성을 조사한 결과 품종에 따라 현저한 차이가 있었으며 섭식성의 분포는 비정규분포에 가까웠고 저섭식성 쪽으로 편기되어 있었다. 또한 MP-O 인공사료 고섭식성은 저섭식성에 대해 열성적 형질로 판명되었으며 결과적으로 열성유전자에 의해 지배되고 있음이 명확해졌다.

• Asian-Australasian Journal of Animal Sciences
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• 제15권1호
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• pp.16-18
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• 2002

During the process of freezing, spermatozoa suffer cold shock which increases their susceptibility to lipid peroxidation which plays an important role in ageing of spermatozoa, shortening their life span and affecting the preservation of semen. An experiment was therefore conducted to study the effect of addition of natural antioxidants into semen diluents on the preservability of buffalo semen. Split semen samples were extended in milk egg yolk diluents fortified with vitamin E (MYE), vitamin C (MYC) and control group (MYO); Tris-egg yolk diluents fortified with vitamin E (TYE), vitamin C (TYC) and control group (TYO) and evaluated for their preservabilities at 4-7$^{\circ}C$ and $37^{\circ}C$. Overall least squares mean of percent motility observed after 0, 24, 48, 72 and 96 h of preservation at 4-7$^{\circ}C$ were 66.70, 54.00, 36.80, 21.90 and 12.50, respectively while the estimates for semen extended in MYE, MYC, MYO, TYE, TYC and TYO were 44.80, 42.70, 38.70, 36.00, 35.20 and 33.00 percent, respectively. The results showed that motility was significantly (p<0.01) affected by extender (extender-antioxidant combination) and preservation interval. Overall least squares mean percent motility observed after 0, 4, 8, 12 and 24 h of preservation at $37^{\circ}C$ were 68.50, 58.90, 45.00, 38.10 and 18.10 percent, respectively, while the estimates for semen extended in MYE, MYC, MYO, TYE, TYC and TYO were 48.20, 49.30, 46.80, 45.30, 42.30 and 42.50 percent, respectively. Extender and storage interval were found to be significantly (p<0.01) affecting spermatozoa motility on room temperature preservation. The results indicated that the incorporation of antioxidants, especially vitamin E, had beneficial effect on preservability of buffalo semen.