• Asian-Australasian Journal of Animal Sciences
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• 제32권8_spc호
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• pp.1284-1295
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• 2019

Considerable progress in reproduction of dairy goats has been made, with advances in reproductive technology accelerating dairy goat production since the 1980s. Reproduction in goats is described as seasonal. The onset and length of the breeding season is dependent on various factors such as breed, climate, physiological stage, male effect, breeding system, and photoperiod. The reproductive physiology of goats was investigated extensively, including hypothalamic and pituitary control of the ovary related to estrus behavior and cyclicity etc. Photoperiodic treatments coupled with the male effect allow hormone-free synchronization of ovulation, but the kidding rate is still less than for hormonal treatments. Different protocols have been developed to meet the needs and expectations of producers; dairy industries are subject to growing demands for year round production. Hormonal treatments for synchronization of estrus and ovulation in combination with artificial insemination (AI) or natural mating facilitate out-of-season breeding and the grouping of the kidding period. The AI with fresh or frozen semen has been increasingly adopted in the intensive production system, this is perhaps the most powerful tool that reproductive physiologists and geneticists have provided the dairy goat industry with for improving reproductive efficiency, genetic progress and genetic materials transportation. One of the most exciting developments in the reproduction of dairy animals is embryo transfer (ET), the so-called second generation reproductive biotechnology following AI. Multiple ovulation and ET (MOET) program in dairy goats combining with estrus synchronization (ES) and AI significantly increase annual genetic improvement by decreasing the generation interval. Based on the advances in reproduction technologies that have been utilized through experiments and investigation, this review will focus on the application of these technologies and how they can be used to promote the dairy goat research and industry development in the future.

• 농업과학연구
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• 제46권3호
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• pp.461-469
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• 2019

The aim of this study was to analyze the contribution of carcass traits (backfat thickness, eye muscle area, carcass weight and marbling score) and the season at slaughter to the price (auction and market) using squared semi-partial correlation. The season at slaughter (summer expressed as season_2, autumn as season_3, and winter as season_4) were added into the estimation as dummy variables, and spring was set as a default variable. In this study, the carcass grades of 22,298 Hanwoo steers slaughtered from 2012 to 2017 were used to performmultiple regression analysis. The rankings of the contribution of the carcass traits and the seasons at slaughter to the auction prices were in the order of marbling score (68.63%), season_4 (11.88%), backfat thickness (10.45%), eye muscle area (6.11%), season_3 (2.19%), season_2 (0.45%) and carcass weight (0.28%). (R-square of the regression = 0.4101). The rankings of the contribution to the total prices were in the order of carcass weight (51.74%), marbling score (32.12%), season_4 (6.04%), backfat thickness (5.54%), eye muscle area (3.22%), season_3 (1.14%), and season_2 (0.19%). (R-Square of the regression = 0.6486). As a result, season_3 and season_4 had a negative effect on the auction price and total price. Because of seasonal event such as Korean Thanksgiving Day and Korean New Year's Day on season_3 and season_4, much supply was needed to meet the high demand. Thus, the seasonal effect at slaughter could be another factor to be cosideredin when considering of slaughter or breeding.

• 한국동물생명공학회지
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• 제36권4호
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• pp.261-269
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• 2021

Because sows are industrially vital for swine production, monitoring for their health or disorder status is important to ensure high reproductive performance. Especially, ambient temperature changes in different season, especially during summer, are directly influenced to the reproductive performance of sows. Although the serum biochemical parameters are widely applied in the veterinary medicine with wide ranges for the physiological process, the values are also influenced by several factors such as age, breed, gender, and stress. In addition, domestic sows in Korea-specific reference interval (RI) for serum biochemistry has not been established yet. Therefore, the present study was aimed to evaluate seasonal variation of RIs in the serum biochemistry in domestic sows in Korea at different seasons and to establish normal RIs using a RI finding program (Reference Value Advisor). Significant difference (p < 0.05) on the different seasons were identified in several serum biochemical parameters including BUN, CRE, GGT, GLU, ALB, TP, LDH and Na in sows. Therefore, we further established RIs, specific in domestic sows in Korea regardless of season. The established RIs based on the serum biochemical values provide a baseline for interpreting biochemical results in the domestic sows in Korea, regardless of seasonal effect. It may contribute to develop a strategy for better reproductive performance by improving breeding management practice and evaluating health of pig herds, which facilitate to avert the economic loss in summer infertility in sows.

• 한국환경생태학회지
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• 제29권3호
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• pp.333-343
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• 2015

본 연구는 국내에서 아직 미흡한 조류 번식지 예측 모형을 이용해 참매의 서식지 예측 및 대체번식지로서 이용 가능한 지역을 선정하고, 향후 참매 번식 가능지역을 대상으로 보호관리 지역을 확대할 수 있는 근거를 제시하기 위한 방안이다. 참매의 번식지는 현장조사에서 확인된 둥지(N=10)를 이용하였으며, 출현지점은 제3차자연환경조사를 통해 확인된 참매출현지점(N=23)을 활용해 분석하였다. 모형변수로는 지형인자 4가지, 자연환경인자(식생) 3가지, 거리인자 7가지, 기후변수 9가지를 활용하였다. 활용변수 중 Random sampling을 통해 확보된 비출현 좌표와 출현좌표간 비모수 검증을 통해 최종 환경변수를 선정하였다. 유의성 검증을 통해 선택된 변수는 번식지 대상 10가지, 출현지점 대상 7가지였으며, 이 변수를 활용해 최종 서식지 예측 모형(MaxEnt)을 구축하였다. 모델 구축결과 번식에 활용된 각 변수별 모형 기여도는 온도의 계절적 변동, 혼효림 과의 거리, 입목밀도, 경급의 순이었으며, 출현지점에 활용된 각 변수별 모형 기여도는 온도의 계절적 변동, 수계와의 거리, 경작지와의 거리, 경사도의 순이었다. 번식지점을 대상으로 한 모델링은 기후환경과 숲 내부에서 번식하는 참매의 특성이 반영된 것으로 판단된다. 예상서식지는 충청북도 중부 이북지역으로 예상되었으며, 그 면적은 $189.5km^2$(2.55%)였다. 충북 이남지역은 청주와 충주 등의 비교적 큰 도시가 발달되어 있는 반면 충청북도 북부지역의 경우 산림과 경작지가 고루 발달되어 있어 번식에 있어 일정한 세력권과 먹이원이 필요한 참매로서는 번식에 유리한 지역일 것으로 판단된다. 출현지점 대상으로 한 모델링은 면적이 $3,071km^2$(41.38%)으로 확인되었으며, 이는 출현지점을 대상으로 하여 단순이동 관찰 및 계절적인 변동 미고려 등의 한계가 있기 때문에 번식지점을 대상으로 한 모델링보다 광범위한 서식예상지역을 예측하였다. 결과에서 확인된 예측지점은 번식지를 대상으로 하였을 경우 정밀한 서식예측이 가능하나, 둥지의 특성상 확인되는 지점이 적고, 참매의 행동영역을 반영하지 못하는 단점이 있다. 반면 출현지점을 대상으로 하였을 경우 더 광범위한 지점에 대한 결과 도출이 가능하였으나, 단순 이동이나 지속적인 이용실태를 반영하지 못하기 때문에 정밀도에서는 다소 떨어진다고 할 수 있다. 다만 이러한 결과들을 통해 참매의 서식지를 예측할 수 있으며, 특히 정밀한 번식지역의 예측자료는 환경영향평가나 개발계획 수립시 서식지 모형 결과를 도입하여 반영할 필요성이 있다.

• 한국양식학회지
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• 제8권1호
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• pp.47-58
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• 1995

거금수도의 양식어장환경 특성 중 식물플랑크톤 군집의 계절변화 특성을 억제하기 위한 현장조사를 1993년 2월, 4월, 8월 및 10월 사계절에 거쳐 25개 관측점을 대상으로 실시하였다. 조사 결과 거금수도에 출현하는 식물플랑크톤 군집의 종조성은 총 40속 65종에 의해 이루어지고 있었다. 특히 중심목 규조류의 출현이 16속 32종으로 전체 출현종의 약$50\%$를 차지하고 있었다. 종의 다양성은 고수온기에 높고, 저수온기에 낮게 나타나고 있었다. 우점종의 계절변화는 겨울에 Skeletonema costatum, Thalassiosira sp. 및 Thalassionema nitzschioides에 의해, 봄에는 Th. nitzschioides와 Asterionella kariana가, 여름에는 S. costatum과 Chaetoceros diadema에 의해, 가을에는 Rhizosolenia alata와 Bacillaria paxillifer 가 우점종으로 출현하여, 연중 규조류에 의한 우점현상이 보여지고 있으며, 계절에 따른 우점좀의 천이도 비교적 뚜렷하게 나타나고 있었다. 또한 본 해역에 출현하는 적조생물은 주로 여름철에 보여지고 있으나, 출현량으로서는 아직 적조발생이 이루는 밀도의 수준은 아니나, 가두리 양식장 설치 등 인위적 오염부하량의 변동에 의해서 발생가능성이 높은 것으로 판단된다. 현존량의 변화는 시간적으로는 년간 $8.8\times10^3$ cells/l 범위로 변화하고 있으며 공간적인 변화는 겨울인 2월이 $12.2\times10^4\pm5.9\times10^4$ cells/l, 봄이 $3.3\times10^4\pm1.4\times10^4$ cells/l, 여름이 $48.4\times10^4\pm40.0\times10^4$ cells/l 및 가을이 $3.6\times10^4\pm1.9\times10^4$ cells/l로 변동하여 겨울과 여름이 봄과 가을에 비해 한 단위 더 높은 변화 양상을 나타내어, 지금까지의 온대해역에서는 봄에 높은 현존량을 나타낸다는 내용과 상반되는 결과를 나타내었다. 이와 같은 결과는 본 해역의 낮은 수심과 큰 조석차에 의한 해수의 조석혼합 등에 의해 식물플랑크톤 군집이 쉽게 영향을 받고 있기 때문으로 추정되었다.

• Journal of Ecology and Environment
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• 제43권2호
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• pp.104-116
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• 2019

Background: The composition of wild bird populations in temperate zones greatly varies depending on phenological changes rather than other environmental factors. Particularly, wild birds appearing in wetlands fluctuate greatly due to the crossover of species arriving for breeding during the summer and for wintering. Therefore, to understand the changes to species composition related to phenology, we conducted this basic analysis of populations to further the cause of the protection of wetland-dependent wild birds. Methods: It is wrong to simply divide a wild bird population investigation into seasons. This study identifies species composition and indicator species that change along with seasons. Wetlands to be surveyed are protected by natural monuments and wetland inventory and are in a state close to nature. In order to identify as many species as possible in wetlands, a survey was conducted in both shallow and deep wetlands. The water depth varied in these areas, ranging from 0.2 to 2.0 m, allowing for both dabbling and diving ducks to inhabit the area. Surveys were conducted using line-transect and distance sampling methods and were conducted at intervals of 2 weeks. The survey was conducted under the following three categories: the eco-tone and emergent zone, the submergent zone, and the water surface. The survey was conducted along a wetland boundary by observing wild birds. A PC-ord program was used for clustering, and the SAS program was used to analyze the changes in species composition. The data strongly indicates that day length is the main factor for seasonal migration periods, despite the fact that climate change and increasing temperatures are often discussed. Results and conclusions: The indicator species for determining seasons include migrant birds such as Ardea cinerea, Alcedo atthis, Anas penelope, and Poiceps ruficollis, as well as resident birds such as Streptopelia orientalis and Emberiza elegans. Importantly, increases in local individual counts of these species may also serve as indicators. The survey results of seasonal fluctuations in temperate zones shows that spring (April to June), summer (July to September), autumn (October), and winter (November to March) are clearly distinguishable, even though spring and summer seasons tend to overlap, leading to the conclusion that additional research could more clearly identify fluctuation patterns in species composition and abundance in the study area.

• ALGAE
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• 제17권2호
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• pp.89-93
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• 2002

Seasonal changes of pigment compositionin two intertidal red algae, Gloiopeltis furcata (Postels et Ruprecht) J. Agardh, and Porphyra yezoensis Ueda, were investigated. Chlorophyll α and phycoerythrin levels were high during winter, but decreased in late spring or summer, with accompanying discoloration from deep red to green or yellow. This discoloation corresponded closely to the fluctuationof phycoerythrin content. Nevertheless, photosynthesis capacity was maintained by the increasing water temperature in the field, suggesting that large amounts of phycoerythrin are not necessary for photosynthesis. Phycoerythrin conten correlated significantly with nitrogen content in both species when the nitrogen level was greater than the level of critical content (1.30% DW in G. furcata, and 2.26% DW in P. yezoensis), indicating that phycoerythrin plays a more important role in the nitrogen status as a nitrogen pool than that of nitrogen critical content. Furthermore, the dependence level of the alage on phycoerythrin as a nitrogen pool was greater in P. yezoensis than in G. furcata because of the remarkable increase of phycoerythrin content in P. yezoensis with increasing jnitrogen content.

• Asian-Australasian Journal of Animal Sciences
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• 제13권4호
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• pp.561-573
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• 2000

Knowledge concerning the nutritional requirements and nutritional problems of fanned deer is limited. Nutritional recommendations must be based on data from domestic ruminants and fanned deer. An understanding of the biology and adaptative characteristics of wild deer is essential for sensible application of sheep and cattle nutritional principles. Nutritional requirements of deer are generally separated into five categories: energy, protein, minerals, vitamins and water. Research on deer nutrition has primarily focused on energy, protein and minerals (phosphorus and calcium). Changes in the nutritional requirements that occur with gestation, lactation, breeding and antler growth should be coordinated with seasonal changes in nutrient availability from forage plants. This paper describes aspects of current knowledge of energy, protein, minerals, vitamins and water requirements. Nutritional problems of. fanned deer are described with recommendations for prevention or control. A comparison of production efficiency of deer, lamb, beef cattle and dairy cattle is included.

• Journal of Dairy Science and Biotechnology
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• 제33권1호
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• pp.69-73
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• 2015

The world is presently facing key challenges due to the population explosion, shortages in renewable sources of energy, and environmental problems. One important aspect of ecological intensification is the use and improvement of marginal lands and spaces often ignored, until now. Goats are known to be well adapted to scrubs, forage trees, and rangelands. Goats could contribute marginally, but significantly, to the growing demand for meat without using arable lands. Since 2000, there were 752 million goats globally, and goat livestock increased by 26.8% in 2010, accounting for 954 million heads. Goats are widespread due to their high adaptability to different environmental conditions and nutritional regimes, high productivity, and low maintenance cost. A significant growth in goat number was noticed in the period 2000~2010 in the Netherlands (+113.83%), in spite of the 9.75% decrease in EU-27. A cheese making goat farm in the Netherlands showed how it can survive in the one fifth size of the average. It may be a good model for the Korean goat industry since it uses seasonal breeding and results in reduced "goaty" flavor in the cheese.

• 한국수정란이식학회지
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• 제20권1호
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• pp.49-53
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• 2005

다양한 발정유기 방법의 반복처리에 따른 분만율은 평균 $90.7\%(236/260)$로 나타났고 생시체중에 있어서 자연 발정구와 발정 유기구에서 차이를 거의 보이지 않았으며 송아지 육성율은 농가의 사육경험이 많을수록 우수한 경향이었고 발정 동기화의 반복처리가 차기번식에 미치는 영향은 확인할 수 없었다. 1. 발정 유기구와 자연 발정구에서 출생한 송아지의 생시체중은 암송아지에서 각각 23.9kg, 24.0kg이었고, 수송아지에서 26.2kg, 24.9kg로써 처리간 차이가 없었다. 2. 산차에 따른 생시체중은 초산에서 23.4kg, 2산에서 25.3kg, 3산에서 26.2kg으로 유의적으로 증가하는 경향이었으나, 5산 이후에서는 비슷하였다. 3. 분만후 발정재귀일수는 대조구에서 80.7일, $PGF_{2}{\alpha}$구에서 92.3일, PRID구에서 78.5일, CIDR구에서 64.5일, $GnRH-PGF\_2{\alpha}-GnRH$ 처리구에서 65.6일로 나타났다. 4. 분만후 수태일수는 대조구에서 137.1일, $PGF_{2}{\alpha}$구에서 147.6일, PRID구에서 141.3일, CIDR구에서 116.6일, $GnRH-PGF\_{2}{\alpha}-GnRH$처리구에서 118일로 나타났다.