• Korean Journal of Ornithology
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• v.25 no.2
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• pp.101-105
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• 2018

On 22 June 2018, we observed the breeding of the Pied avocet (Recurvirostra avosetta) at landfill sites in Saemangeum, Jeollabuk-do Province. The breeding ground was a temporary swamp, and four juvenile were constantly observed with adult bird. This observation is the first breeding record of Pied avocet (Recurvirostra avosetta) in Korea.

• Journal of Embryo Transfer
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• v.29 no.1
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• pp.7-12
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• 2014

This work was conducted to study the improvement of reproduction rate from the breeding data collected from four farms from January 2007 to October 2010. The average numbers of service per conception were 1) A farm $1.7{\pm}0.1$ times, 2) B farm $1.5{\pm}0.1$ times, 3) C farm $1.5{\pm}0.1$ times, 4) D farm $1.4{\pm}0.1$ times. The average days from calving to conception was $77.4{\pm}4.8$ days in A farm, $150.8{\pm}11.2$ days in B farm, $90.4{\pm}4.5$ days in C farm, and $71.4{\pm}2.5$ days in D farm. Number of artificial insemination (AI) service per conception was higher at the 30 days before first AI ($2.1{\pm}0.2$ times) than at the 31 days after first AI, and the days from calving to conception were shorter at the 90 days before first AI than at the 91 days after first AI. After timed AI (TAI) treatment, the pregnancy rate was 60.3% for the 58 cows with reproductive disorder. In order to improvement of reproduction rates, the farms has to improve the accuracy of estrus detection, pregnancy diagnosis, check-up for reproductive health, and control of day for first AI periods after calving. The result suggests that farmers need the careful management and reproductive examination of farm animals to improve of reproductive efficiency.

• Korean Journal of Ornithology
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• v.25 no.2
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• pp.133-135
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• 2018

Plaintive Cuckoo (Cacomantis merulinus) is a small cuckoo species in Family Cuculidae that is mainly distributed in the Oriental Region. On May 1. 2016, one juvenile Plaintive Cuckoo was found at Somaemuldo Island, Korea ($34^{\circ}37^{\prime}38.73^{{\prime}{\prime}}N$ $128^{\circ}33^{\prime}0.44^{{\prime}{\prime}}E$). The bird was identified as C. merulinus by its morphological traits, especially primary projection, the shape of bars on tertials, and pale supercilium. These characteristics were distinctive from other similar small cuckoos in genus Cacomantis and Cuculus, during the field observation and examination of photographs. This record is the first of this species in Korea, and the northernmost record of this species.

• Korean Journal of Environmental Biology
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• v.28 no.2
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• pp.49-55
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• 2010

There are only 10,000 Saunders' Gull's (Larus saundersi Swinhoe) surviving in the world today. But they are being threatened by coastal habitat, degradation, development pressure and disturbance by humans. Their first breeding record in Korea was in 1998 and the breeding status has been studied, however, the breeding status is not sufficient for this species. This study was performed from May 1999 to June 2009 to clarify breeding populations and trend of the Saunders' Gull population in Korea. The results indicate that the breeding population has been increasing gradually from 300 to 1,300 individuals, though disturbance increased. As threats to the breeding birds, physical environmental factors such as development and human disturbance were identified as a major threatening factors. Also, as a secondary factor, eggs and chicks are falling pray to predators. Incheon bay breeding places have been created by a landfill projects for the purpose of urban and industrial development, thus, these places will no longer be available for this species. In addition, the breeding habitat has been reduced and changed by expansions of development on the ground. Therefore, well planed management schemes should be provided for the species' breeding population to be continually breed and survive.

• Journal of Embryo Transfer
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• v.22 no.2
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• pp.111-114
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• 2007

This study was carried out to investigate the reproductive performance of average (less than 10,000 liters milk in 305 days) and high yielding (more than 10,000 liters milk in 305 days) Holstein cattle at commercial dairy herds (n=22). Data on milk progesterone (10 to 60 days postpartum), days to post-partum estrous, days to post-partum conception, service per conception and calving interval were recorded for two consecutive years. Post-partum milk progesterone concentration and days to reach peak milk progesterone concentration were similar in high and average yielding cows. High yielding cows took more days to show signs of first postpartum estrous than average yielding cows. Post-partum conception was 20 days earlier in average yielding cows than high yielding cows. Artificial insemination per conception was similar between average and high yielding cows. Calving interval was 26.9 days longer in high yielding cows compared to average yielding cows. In conclusion, better reproductive and feeding management may help improve the reproductive performance of high yielding dairy cattle in commercial dairy farms.