• Asian-Australasian Journal of Animal Sciences
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• 제24권9호
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• pp.1192-1198
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• 2011

Peri-partum metabolic profile was evaluated in winter and summer calving, with 15 Murrah buffaloes in each seasonal group. In summer calvers, significantly lower values were observed for blood plasma urea nitrogen (BUN) at day 30 pre-partum (p<0.05), on calving day (p<0.05) and at all other stages (p<0.01); plasma non-esterified fatty acids (NEFA) values were significantly lower on day 30 pre-partum (p<0.01) and on day 60 post-partum (p<0.05). This was associated with significant reduction in days to first service (DFS) and service per conception (SPC) and an overall better reproductive performance in terms of service period, risk to first service on days 60, 90 and >90, and pregnancy risk to first service up to days 60 and 90. This may be attributed to better pre-partum nutritional status. Cervical and uterine involution were completed in fewer days, involutional changes took place at a faster pace and there were a lower number of abnormal involutional changes in winter compared to summer season. This may be attributed to better post-partum nutrition and less environmental stress. However, validation requires further targeted cohort investigation with a large sample size.

• 대한수의학회지
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• 제30권4호
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• pp.499-505
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• 1990

The seasonal availability and abundance of the free-living stages of sheep nematodes is a key factor in the occurrence and severity of parasitic infection, and studies of larvae ecology could result in more rational control measures. In the present study seasonal pasture contamination and availability of nematodes for grazing sheep was examined as a baseline work for nematode control program at Namwon Branch, National Animal Breeding Institute during the period April 1988 through March 1989. Standard meteorological measurements were available from Unbong Sub-station, Honam Crops Experiment Station located about 200m from the experimental site. A total of 5 kinds of nematode larvae was detected: Haemonchus contortus was most prevalent (38.0%) with a decreasing order of Ostertagia spp (35.1%), Trichostrongylus spp (19.8%), nematodirus spp (6.6%), and Oesophagostomum spp (0.5%). A succession of species was recorded, in particular Ostertagia spp in May; Haemonchus contortus in June and July; Trichostrongylus spp in July and August; Nematodirus spp in August and September. These results can be incorporated into the nematode control program. To make a more rational control program, however, repeated herbage larval counts should be undertaken soil larval counts and fecal larval counts in the future.

• 한국가금학회지
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• 제23권3호
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• pp.153-160
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• 1996

Though pheasants (Korean ring-necked pheasant) have been raised for several decades, their behavior and wild nature are far from domestication. The pheasant is a seasonal breeding species and lays a limited number of eggs in a breeding season. The growth rate and feed efficiency of pheasants are very low as compaired with those of chicken for meat purpose. In addition, the breeder's access to one's herd for care is not easy. From these reasons, pheasants seem to be unsuitable for meat production in a large flock at present. However, pheasant raising is expected to increase slowly in accordance with rising demand for special poultry meat. Therefore, it is necessary to improve techniques about raising, feeding and rnanagement, so that the consumer price of pheasant meat can be lowered down reasonably.

• 한국패류학회지
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• 제11권2호
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• pp.147-163
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• 1995

The unionid family Unionidae contains several genera in Korea, among which occru considerable variations in life histories and sexual conditions. Seven species from the Korea(Anodonta arcaeformis flavotincta, A. woodiana, Unio douglaseae, U. douglasiae sinuolatus, Lamprotula gottschei, Lanceolaria acrorhyncha, Solenaia triangularis)were stueide in order to identify and describe the seasonal gonadal activity and the visceral sex. The gonads of seven species were histologically examined by using the paraffin block technique for sectioning. All seven species were uniformly dioecious and testicular activity in six species except one species, S. triangularis, generated sperm-morulae(multinucleated cell). The annual reproductive cycle of the seven species could be classified into five successive stages; multicative, growing, mature, spent, deginerative and resting stages. The breeding season of six species was the summer and that of A. a. flavotincta was the winter.

• Journal of Ecology and Environment
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• 제31권1호
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• pp.9-15
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• 2008

Growth and reproduction of Palaemon serrifer were described and analyzed in a population inhabiting tide pools in warm temperate waters in Korea. The water temperature varied greatly in the tide pools, ranging from 8$^{\circ}C$ to 27.8$^{\circ}C$ Population structure and growth were investigated using size frequency distribution data collected from January to December 2003. Sex ratios fluctuated, but were almost equal during the breeding period. Growth was continuous and size increased gradually throughout the year. Adult females were larger and grew faster than males. von Bertalanffy growth parameters for a one-year sample of females and males were estimated as $L_{i\ddot{A}}$ = 11.32, K = 0.311, $t_0$ = -0.4115 and $L_{i\ddot{A}}$ = 8.36, K = 0.228, $t_0$ = -0.9693 respectively. Breeding was seasonal, starting in May, peaking in August, and finishing by the end of August. The species showed continuous production of successive broods. Laboratory observation showed that females with embryos near hatching had ovaries filled with vitellogenic oocytes ready for spawning. The reproductive output (effort) of each female (mean number of eggs: $552{\sim}1355$) was not high. The mean embryo volume, $0.078mm^3$, is relatively small, indicative of low energy allocation to each embryo. Recruitment of juveniles was closely linked to the breeding period, beginning in September.

• Asian-Australasian Journal of Animal Sciences
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• 제10권1호
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• pp.75-78
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• 1997

Season is very important as it defines the contemporaries for sire and cow evaluation. An attempt is made for defining season for animal model evaluation of Sahiwal animals, using 1,227 records from 730 cows. Cows were required to have a lactation length of 305-days. Ten different combinations of months for two, four, five or other seasons were tried. The other fixed effect in the model was age defined within parity. The random effects were permanent environment and animal's breeeding value along with the residual effects. A single trait animal model was used where all known relationships of an animal were incorporated in a relationship matrix. The error variance from the fitted model decreased as the number of year-season combinations increased, indicating a month-year model to be more appropriate. This, on the other hand, decreased the number of contemporaries for certain subclasses to a minimum of one, making the bull comparisons invalid. Use of a two season scenario, with winter (November through February) and summer (March through October) was better than the other combinations in terms of error variance of the fitted model and the number of lactations represented in any year-season subclass.

• Asian-Australasian Journal of Animal Sciences
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• 제29권9호
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• pp.1239-1246
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• 2016

The breeding of yaks is highly seasonal, there are many crucial proteins involved in the reproduction control program, especially in follicular development. In order to isolate differential proteins between mature and immature follicular fluid (FF) of yak, the FF from yak follicles with different sizes were sampled respectively, and two-dimensional gel electrophoresis (2-DE) of the proteins was carried out. After silver staining, the Image Master 2D platinum software was used for protein analysis and matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF-MS) was performed for differential protein identification. The expression level of transferrin and enolase superfamily member 1 (ENOSF1) was determined by Western blotting for verification analysis. The results showed that 2-DE obtained an electrophoresis map of proteins from mature and immature yak FF with high resolution and repeatability. A comparison of protein profiles identified 12 differently expressed proteins, out of which 10 of them were upregulated while 2 were downregulated. Western blotting showed that the expression of transferrin and ENOSF1 was enhanced with follicular development. Both the obtained protein profiles and the differently expressed proteins identified in this study provided experimental data related to follicular development during yak breeding seasons. This study also laid the foundation for understanding the microenvironment during oocyte development.

• 대한수의사회지
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• 제20권1호
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• pp.19-25
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• 1984

Seasonal infestation rate of Sarcoptes scabiei var suis were surveyed in 560 slaughter pigs of Kwangju area by means of microscopical detection of eggs and mites from ear scrapings, supplementing morphological observation of the mites. The results were su

• Journal of Animal Science and Technology
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• 제49권4호
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• pp.443-450
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• 2007

본 연구에서는 엘크 사슴의 계절별 정액성상 변화, 동결정액의 융해 후 활력 및 발정동기화 후 인공수정 시간이 수태율에 미치는 영향을 조사하여 효율적인 인공수정 방법을 제시코자 시도하였다. 수사슴에서 정액의 연중 변화는 정액량, 정자 농도, 총 정자 수 및 정자 활력은 7월부터 급격히 증가 되어 정액량과 총 정자 수 및 정자 운동성은 10월에 최고치에 달했고, 정자 농도는 9월에 가장 많은 것으로 조사 되었다. 그 후 정액량, 정자농도, 총 정자 수 및 정자 운동성은 점진적으로 감소하여 정액 양, 정자 농도는 4~6월, 총 정자 수는 4~5월 및 정자 운동성은 6월에 최저 수준으로 감소하였다.번식계절(9~2월)과 비번식계절(3~8월)의 정자 농도, 총 정자 수 및 정자 운동성은 번식계절이 유의적으로 높게 조사되었다(P<0.05). 번식계절과 비번식계절에 채취한 정액의 동결과정 중에 정자 운동성의 결과는 채취 직후, 5℃냉각 후 및 동결 융해 후 활력이 번식계절이 높은 것으로 조사 되었다(P<0.05).인공수정 시간에 따른 수태율은 CIDR 제거 후 60시간에 인공수정 한 처리구가 수태율이 다른 시간들 보다 다소 높았으나 유의적인 차이는 나타나지 않았다.이러한 연구 결과는 엘크 사슴에서 정액 생산과 인공수정을 수행함에 있어 유용한 자료로 이용 될 수 있으며, 발정동기화 후 호르몬 변화, 배란 및 수정 적기 등에 관한 연구가 추가적으로 수행되어야 할 것으로 사료된다.

• Journal of Animal Science and Technology
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• 제64권1호
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• pp.1-9
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• 2022

Equilume light masks had no impact on hastening the resumption of estrous cyclicity in mares maintained in outdoor pastures on the mainland of Korea due to the cold weather conditions. Jeju Island is a major horse-breeding site in Korea and is warmer than the mainland during the winter season. Therefore, the primary objective of this study was to explore the efficiency of the Equilume light mask on the resumption of seasonal estrous cycles in Thoroughbred mares on Jeju Island. A total of 20 nonpregnant mares were randomly divided into the Equilume light mask (n = 9) and stable lighting (n =11) groups. The experiment was performed at seven different horse-breeding farms located on Jeju Island from November 15, 2020, to February 15, 2021. The mares were exposed to the respective lights from 16:00 to 23:00. Follicle size and uterine edema were measured by ultrasound scanning. Body condition scores (BCS) were also monitored during the experiment. Statistical analysis was conducted using the SAS and SPSS software, and p-values of < 0.05 were considered statistically significant. Two of the nine (22.2%) mares in the Equilume light mask group and three of the 11 (27.28%) mares in the stable lighting group were still cycling in December and January, which were considered as all-year-round cycling mares. On February 15, there was no difference between groups in the resumption of early seasonal estrus cycle, which was determined by follicles > 25 mm in addition to uterine edema. All mares in the Equilume light mask group and five of the eight mares (62.5%) in the stable lighting group had resumed cycling. Interestingly, six of the seven mares (87.5%) in the Equilume light mask and four of eight mares (50%) in the stable lighting group had already ovulated on February 15 (p > 0.05), as determined by the presence of a recent corpus luteum. No difference was observed in BCS and uterine edema between groups (p > 0.05). In conclusion, the Equilume light mask can be an effective approach to induce early seasonal estrus cycles of mares in Jeju Island, and it also enhances the efficiency of farm management by reducing labor.