• Korean Journal of Poultry Science
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• v.34 no.4
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• pp.279-286
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• 2007

This study was conducted to induce molting with DDGS and non-salt diet and compare the effect of feeding molting and fasting molting on the performance, egg quality, and visceral organs in laying hens for animal welfare. One-hundredeight 62-wk-old White Leghorn hens that egg production was over 80% and average weight was $1.8{\pm}0.1kg$ were used in this study. Treatments were control(non-molt treatment), feeding molt treatment(DDGS, non-salt diet), and fasting molt treatment. The four treatments were administered to three replicate group of nine hens wherein each group. All treatment groups were fed the basal diet(CP 15%, ME 2,700 kal/kg) for two weeks as the adaptation period. Test Periods were 28 days at all treatments. Egg production decreased for 18 days to be 0% at feeding molting treatment, and for 17 days to be 0% at non-salt feeding molting treatment. Egg production stopped for 6 days at fasting molting treatment. Egg production restarted after 12 days molt at feeding molting treatment, while after 16 days at fasting molting treatment. On the egg quality was improved at molting treatments (p<0.05) except egg yolk. Egg shell tissue was crowded at molting treatment to compare to control. Liver weights, heart weight, and oviduct weight of laying hens decreased at molting treatments(p<0.05). Finally, feeding molting might could be replaced fasting molting on the welfare and further studies were needed about molting program.

• Korean journal of applied entomology
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• v.19 no.2 s.43
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• pp.97-101
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• 1980

Present studies were carried out to investigate the life history of potato tuber moth, Phthorimaea operculella (Zeller), under laboratory conditions in Suweon. Studies on its life-cycle on stored potato tubers in the laboratory showed that seven generations were reared in a year and the development from egg to adult was completed in an average of 49.4 days in spring at $18.2^{\circ}C$., 21 days in summer at $26.8^{\circ}C$., 26.1 days at $24.2^{\circ}C$., and 39 days in autumn at $19.6^{\circ}C$. The females laid an average of 101 eggs each, with a maximum of 242 and longevity of adults 17.6 days in spring at $15.1^{\circ}C$., 8.1 days in May-September at $25.3^{\circ}C$., and 13.3 days in autumn at $16.8^{\circ}C$.

• Korean journal of applied entomology
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• v.36 no.1
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• pp.43-47
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• 1997

This study was carried out in the laboratory to clarify effects of different temperature of Protopulvinaria mangiferae(Green) on development, survivorship and reproduction. Developmental period of the mango shieldscale from crawlers to preoviposition adult decreased as temperature increased. The threshold temperature andthermal constants for the development of one generation were 11.7"C and 1000.0 day-degrees, respectively. At25$^{\circ}$C and 30$^{\circ}$C, survival rate from egg to preoviposition adult were 82% and 6096, respectively. Hatchability ofeggs was more than 99% at both condition. The reproductive period overaged 50 days(2SnC) and 33 days(30$^{\circ}$C). After mature adult began to reporduce, and more than 50% of the crawlers emerged during the firsthalf of their life time. The net reproduction rate per generation(R), mean length of a generation0 and intrinsicrate of natural increase(r, ) were higher at 25$^{\circ}$C than at 30"C, and the values measured at 25$^{\circ}$C were 132.6, 76.2 and 0.064/female/day, respectively.

• Korean journal of applied entomology
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• v.31 no.4
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• pp.492-495
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• 1992

Life cycle of the mirid predator, Cyrtorhinus lividipennis, was observed on the constant temper¬ature. Egg periods were 14.43, 9.33 and 6.94 days at $20^{\circ}C$, $25^{\circ}C$ and $30^{\circ}C$, respectively. Nymph periods were 24.3, 14.42, and 11.90 days at $20^{\circ}C$, $25^{\circ}C$ and $30^{\circ}C$, respectively and fe¬male longevity was 11.20, 11.93 and 11.87 days at above temperatures. Relationships between constant temperature and the developmental velocity of egg, nymph and egg-nymph were lin¬ear over temperatures tested. The calculated threshold temperatures of development were $10.7^{\circ}C$ in egg, $9.8^{\circ}C$ in nymph and $10.2^{\circ}C$ in egg-nymph. Total effective day-degrees were 133.9 in egg, 235.8 in nymph and 368.0 in egg-nymph. Number of eggs laid was 26.0 and 22.4 at $24^{\circ}C$ and $30^{\circ}C$, respectively.

• Journal of Korean Society of Forest Science
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• v.100 no.3
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• pp.397-401
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• 2011

This study was conducted to clarify the breeding ecology of tits Parus spp. used artificial nest boxes in a deciduous forest at the Ansung Campus, Chung-Ang University from March through July, 2006 to 2010. Varied tit Parus varius, marsh tit P. palustris and great tit P. major bred in artificial nest boxes during our study period. There were no differences in number of breeding bird pairs among different entrance diameters of artificial nest boxes. The number of breeding pairs of great tits was the most highest among tits and that of varied tits was the least. Great tits mainly used 40 mm and 35 mm artificial nest box entrance diameter and marsh tits preferred 30 mm entrance diameter. In three tits species, there were differences in first egg date, clutch size, brood size, egg incubation period, nestling care period and breeding success among study years. It is needed the study on long-term ecological research about breeding ecology of tits related with habitat conditions.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 2001.11a
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• pp.142-142
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• 2001

• KOREAN POULTRY JOURNAL
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• v.38 no.8 s.442
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• pp.76-77
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• 2006

해마다 사양관리 책이 발행되는 양돈과는 달리 아직까지 양계분야에서는 사양관리 단행본의 출시가 많지 않아 양계인들에게 정보를 제공하는데 한계를 보여왔다. 본회에서는 유한진 필자와 함께 오랜 준비기간을 거쳐‘산란계 사양관리 단행본’을 출간하게 되었다. 따라서 본지는 19년동안 양계산업 다방면에서 활동했으며 축산기술사이자 우성사료 양계PM으로 활약중인 유한진 필자를 만나 단행본 출판배경과 그의 청사진을 들어보았다.

• Journal of Veterinary Clinics
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• v.28 no.6
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• pp.581-585
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• 2011

Either the fasting during natural molting or the starvation in induced molting would be a severe metabolic stress to laying hens. The metabolic stress during starvation and subsequent refeeding syndrome could lead to unbalance of mineral homeostasis, including $Mg^{2+}$, $K^+$ and P required by ATP synthesis. Since $Mg^{2+}$ is a fundamental ion for normal metabolic processes and stress may not only increase in demands of $Mg^{2+}$ but also produce consequence of $Mg^{2+}$ deficiency, we investigated the changes of blood ionized and total ions related to starvation during molting in laying hens. We founded the significant decrease in blood $Mg^{2+}$ and $K^+$ accompanied by the changes of biochemical parameters relating to increased metabolic stress after molting. These results suggested that appropriate $Mg^{2+}$ and $K^+$ supplements to laying hens could have beneficial effects during molting and subsequent refeeding that could produce a severe hypomagnesemia and hypokalcemia.

• Korean journal of applied entomology
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• v.29 no.4
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• pp.217-221
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• 1990

Some biological phenomena of Anagrus incarnatus Haliday, an egg parasitoid of planthopper, were studied under three different constant temperatures. Duration from egg to adult emergence of the parasitoid from the BPH eggs were 21.5, 13.6 and 10.6 days under $20^{\circ}C$, $25^{\circ}C$ and $30^{\circ}C$, respectively. Rate of the development was highly correlated with temperature. The critical temperature was estimated as $10.0^{\circ}C$ and the effective degree days was 210.3 day-degree. Durations for the development of A. incarnatus under 25$\pm$$1^{\circ}C$ (16L : 8D) were 12.4, 12.5 and 12.1 days from eggs of N. lugens, S. furcifera and L. striatellus, respectively. Duration of the development of A. incarnatus from 1, 3, 5, 7 days old BPH eggs were 12.5, 12.1, 12.9 days, respectively. The average longevity of adult was 5.3 days under 25$\pm$$1^{\circ}C$. Number of the ovarian and practically oviposited eggs were 34.8$\pm$28 and 28.3$\pm$0., respectively. Female A. incarnatus laid most of the eggs within few days after the emergence ; over 60% within 24 hours, nearly 90% upto the 2nd day, and nearly 100% upto the 3rd day.

• Korean Journal of Poultry Science
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• v.11 no.1
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• pp.49-64
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• 1984

During the 1978-79 Newcastle disease (ND) epizootic period, a detailed survey was conducted on the five representative farms which had been following one of the recommended vaccination programs. When the disease broke out during laying period, clinical symptoms were mild to moderate respiratory distress and greenish diarrhea. Affected flocks experienced weekly mortality from less than 1% to 17%. Egg production returned to normal 18 to 36 days after the initial signs appeared although some flocks never returned to normal. On postmortem examination,, most affected chickens showed severe hemorrhagic lesions in the duodenum, hematoma on ova, and heavy fat accmulation on various visceral organs. Most of the NO affected flocks had geometric mean hemagglutination inhibition antibody(HIA) titers of 7 log$_2$ or higher two to three weeks after the appearance of clinical signs. These HIA titers were at least 16-fold higher than those before infection. Flock mean HIA titers before infection were usually lower than 3 log$_2$. Severity of clinical signs and anamnestic antibody response were maximum in the flocks whose vaccination immunity was insufficient or waned considerably. Observations showed that even young birds, if properly vaccinated, could get effective protection from field ND exposure.