• International Journal of Industrial Entomology and Biomaterials
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• v.4 no.2
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• pp.109-115
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• 2002

With the objective of selecting suitable breeding resource material, 10 polyvoltine and 10 bivoltine breeds were drawn from the germplasm collection of Central Sericultural Research and Training Institute, Mysore, and evaluated for 3 seasons comprising one year (6 trials). Data were collected on seven traits of economic importance such as fecundity, pupation rate, cocoon yield, cocoon weight, cocoon shell weight, cocoon shell ratio and filament length, and statistically analysed with two-way classification, Joint scoring method and evaluation index. Significant seasonal variations (P < 0.01) were observed in both polyvoltine and bivoltine breeds. Polyvoltines BL27, BL36 and BL54 and bivoltines CSR2, CSR4 and Daizo scored highest ranking values in all the three methods. Hybridization was initiated based on larval markings and cocoon shapes. Seasonal variations were discussed.

• Korean Journal of Veterinary Research
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• v.32 no.2
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• pp.275-280
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• 1992

To investigate the age at puberty and the seasonal breeding in Korean native goats, progesterone concentrations were measured in blood. Blood samples were collected from 8 goats at 10 day intervals from 2 months of age until the first estrus after birth, and then every 5 days for a further estrous cycle and the seasonal breeding. The mean age and weight at puberty were $195{\pm}57$ days($mean{\pm}S.D.$, range : 107~260 days) and $11.1{\pm}0.9kg$(range : 9.8~12.0kg), respectively. The mean age at first pregnancy after birth was $241{\pm}109$ days(range : 107~273 days). The estrus was observed 47.6% from October to December, and was highest in fall(38.1%) and lowest in spring and summer(14.3%). However, the estrus was observed every season. About 67% of total conception occurred form October to January. The parturition occurred 41.7% in spring, 25.0% in summer and winter, and 8.3% in fall, respectively. These results suggest that Korean native goats do not have a breeding season, but the reproductive activity is influenced by the season.

• Korean Journal of Animal Reproduction
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• v.25 no.1
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• pp.29-33
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• 2001

This study was conducted to investigate the effects of various estrus synchronization and seasonal breeding in Hanwoo. Delivery interval and number of service per conception were 412.9 and 1.76 in the annual breeding and 376.59 and 1.48 in the seasonal breeding, respectively. The percentage of cows exhibiting estrus in PG $F_{2{\alpha}}$, PRID, CIDR and CnRH-PG $F_{2{\alpha}}$-GnRH were 68.1%(141/207), 71.42%(15/20), 56.8%(33/38) and 93.1%(216/232), respectively. A greater percentage of GnRH-PG $F_{ 2{\alpha}}$-GnRH treatment became pregnant(91.1%) than across all treatments(75.0%, 81.0%, 89.6%). The results show that GnRH-PG $F_{2{\alpha}}$-GnRH treatment f3r pregnant in Hanwoo seems to be more effective than the others.

• Journal of Dairy Science and Biotechnology
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• v.24 no.2
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• pp.1-9
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• 2006

Goat milk is digested better than cow milk, because the fat globules in goat milk are smaller and the protein is similar to human milk, and assimilated easily. Goat milk is particularly rich in taurine (4.7mg/100mL) and retinol (40mg/100mL). Therefore, it might be recommened to heal dyspepsia and infants allergy by cow milk. However, during winter, supply of goat milk products are unsteady in Korea, because unbalance of demand and supply is resulted from seasonal breeding. Dairy industry for goat milk will be able to grow much more, if goat milk products can keep steady supply without changing by season. This review includes the physicochemical characteristics of goat milk, domestic production of goat milk, domestic goat milk products and future development.

• Applied Microscopy
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• v.40 no.1
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• pp.37-45
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• 2010

Captured wild specimens of the big white-toothed shrew, Crocidura lasiura were classified into three age classes by tooth wear and height of molars, and seasonal variations of breeding and reproductive organs were examined. Juveniles had not tooth wear in molars and height of the third molars were lower than the first and second molars, and had only non-breeding condition. Young adults had little tooth wear and the third molars reached to the first and second molars, and old adults had heavy tooth wear in molars, young adults and old adults had breeding or non-breeding condition according to the season. On the basis of histological examination, seasonal variations of breeding were confirmed that breeding condition of young and old adult males were continued from early February to early October although the breeding activity was the highest in April, that of females were continued from the end of March to October, males reached sexual maturity earlier than females. Whereas the breeding condition seems to cease for non-breeding season because of the deficiency of food resources, soil invertebrates. Young and old adult males of the breeding season had large testes with enlarged seminiferous tubules that were filled with numerous germ cells, and expanded caudal epididymides with a vast number of spermatozoa, and were more than 10.0 g in the body weight and 0.03 g in the testis and epididymis weight. The females of the breeding season were pregnant condition with 4~6 litters or had the Graafian follicles and the corpus lutea in the ovary, and were more than 9.6 g in the body weight.

• The Korean Journal of Ecology
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• v.22 no.5
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• pp.311-316
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• 1999

Community organization of the drosophilid flies was investigated with respect to the seasonal variation of the species abundance at the natural forests on Mt. Soribong in Kwang-nung (Kyung-Ki Do, Korea) from May to October 1996. The dominant species were Amiota okadai. Scaptomyza pallida, Hirtodrosophila sexvittata. Drosophila bizonata. D. unispina. and D. brachynephros in the annual collection. A. okadai was found with numerically dominance in April and was found in June with less superiority. S. pallida showed their highest peak in occupational in May and after soon they decreased. There was a remarkable increase in the numbers of H. sexvittata in July. This increase may be coincident with the appearance of fungi which provide a breeding site for this species in the forest. On the other hand, D. biauraria and D. triauraria showed their highest peak in May and after soon they decreased, and in September they made the lower peak again. Four species (D. anguraria. D. brachnephros, D. nigromaculata, D. unispina) of qunaria group were found with dominance in August to September. These results suggest that the predominant species in the forest avoid niche overlap by means of seasonal separation of breeding, which is strongly affected by factors associated with season in the deep wooded forests.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.8
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• pp.1067-1072
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• 2001

An experiment was conducted on eight bullocks of Hariana cattle study draft efficiency using different appliances, changes in their physiological, biochemical and haematological parameters, and how the body tries to maintain these within normal physiological range. Blood collection was done at pre-exercise, three hours after exercise and two hours post exercise in summer and winter seasons of the year 1990-91. Average pulse rate and respiration rate per minute were found to be $63.09{\pm}0.78,\;25.60{\pm}0.54,\;97.21{\pm}2.51,\;63.37{\pm}2.70,\;64.05{\pm}1.90,\;25.33{\pm}1.20$, respectively, at pre-exercise, three hours exercise and two hours post exercise rest. The seasonal differences were found to significant and the values were higher in summer than in winter. After two hours post exercise rest Hariana bullocks regained their normal values for all the parameters, except that pulse rate, respiration rate and serum sodium during summer did not reach the pre - exercise levels.

• Applied Microscopy
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• v.40 no.3
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• pp.125-132
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• 2010

Captured specimens of the lesser white-toothed shrew, Crocidura suaveolens were classified into three age classes by tooth wear and seasonal variations of reproductive organs were investigated. Molars of juveniles had not tooth wear and the height of the third molars were lower than the first and second molars, young adults had smooth tooth wear and the third molars reached to the first and second molars, and old adults had heavy tooth wear and the third molars also reached to the first and second molars. On the basis of histological examination, seasonal variation of breeding was confirmed that breeding season of adult males was from early February to early October, having a peak of the breeding in April and July, and non-breeding season was from in the middle of October to late January. Young and old adult males of the breeding season had large testes with enlarged seminiferous tubules filling with numerous germ cells and expanded caudal epididymides with a vast number of spermatozoa, Young and old adult males of the non-breeding season had the small testes with the extremely slender seminiferous tubules filling with only spermatogonia and the reduced caudal epididymides without spermatozoa. Males weighing more than 3.9 g in the body weight and 0.013 g in the testis and epididymis weight reached sexual maturation in breeding season, and the females weighing more than 3.8 g in body weight of the breeding season were pregnant condition having 5~6 litters or had the Graafian follicles and the corpus lutea in the ovary.

• Korean Journal of Veterinary Research
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• v.40 no.2
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• pp.197-211
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• 2000

The pineal body have been known to be affected by superior cervical ganglia, and most of its nerve fibers containing peptidergic neurotransmitters have been considered to be originated from this ganglia. To confirm this relationships, some peptidergic neurotransmitters were identified in both of pineal body and superior cervical ganglia of the Korean native goat, which were divided into two group; breeding season and non-breeding season. The localizations of two catecholamine-synthesizing enzymes; tyrosine hydroxylase (TH) and dopamine beta-hydroxylase (DBH), were investigated by immunohistochemistry in the superior cervical ganglia and the pineal body of adult Korean native goats. Substance P (SP), calcitonin gene-related peptide (CGRP), vasoactive intestinal polypeptide (VIP), neuropeptide Y (NPY) and galanin (GAL) were also identified in these organs by immunohistochemical and double immunofluorescent methods. In superior cervical ganglia, immunoreactivities for TH and DBH were confirmed in the same ganglion cells. The immunoreactivites for SP, VIP(only in male), NPY and GAL were identified in both of ganglion cell bodies and nerve fibers in the ganglia. CGRP immunoreactivity, however, was observed only in nerve fibers. Most NPY- and VIP-immunoreactive(IR) ganglion cells also contained TH. SP and TH were colocalized in the cell bodies, but not in the nerve fibers. TH immunoreactivity was shown in almost all of ganglion cells in the superior cervical ganglia. The immunoreactivity for NPY had some seasonal variation and was stronger in breeding season than in non-breeding season. In pineal body, lots of TH-IR fibers were observed throughout the parenchyma including the pineal stalk and most of them also contained DBH. SP- and NPY-IR fibers were also immunostained with TH or DBH. But a few SP- and NPY-IR fibers were not colocalized with TH or DBH. Exceptionally, a bipolar neuron-like cell was observed to be immunostained with NPY in the pineal body. A few CGRP and GAL-IR fibers were observed, while VIP-IR fibers were not present. It is concluded that most TH- and DBH-IR fibers as well as the peptidergic immunoreactive fibers of the pineal body might be originated from the superior cervical ganglia. Some peptidergic immunoreactive fibers, however, might be come from other regions of brain. We also suggest that NPY in pineal body plays a important role for pineal function. The seasonal variation of NPY immunoreactivity indicates that the synthesis and use of NPY may be different between in breeding and non-breeding seasons.

• Korean Journal of Environmental Agriculture
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• v.32 no.4
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• pp.294-303
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• 2013

BACKGROUND: It is well known that rice-fields can provide excellent foraging places for birds including seasonal migrants, wintering, and breeding and hence the high biodiversity of rice-fields may be expected. However, how environmental change including climate-changes on life-history and population dynamics in birds on rice-fields has not been fully understood. In order to investigate how climate-change affects population migratory patterns and migration timing, I modeled a population dynamics of birds in rice-fields over a whole year. METHODS AND RESULTS: I applied the Lotka-Volterra equation to model the population dynamics of birds that have been foraging/visiting rice-fields in Korea. The simple model involves the number of interspecific individuals and temperature, and the model parameters are periodic in time as the biological activities related to the migration, wintering and reproduction are seasonal. As results, firstly there was a positive relationship between the variation of seasonal population sizes and temperature change. Secondly, the reduced lengths of season were negatively related to the population size. Overall, the effects of the difference of lengths of season on seasonal population dynamics were higher than the effects of seasonal temperature change. CONCLUSION(S): Climate change can alter population dynamics of birds in rice-fields and hence the variation may affect the fitness, such as reproduction, survival and migration. The unstable balances of population dynamics in birds using paddy rice field as affected by climate change can reduce the population growth and species diversity in rice fields. The results suggest that the agricultural production is partly affected by the unstable balance of population in birds using rice-fields.