• 환경생물
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• 제32권3호
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• pp.211-215
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• 2014

본 연구에서는 미국 뉴햄프셔주 13개 임분의 낙엽활엽수림에서 5년간(1994~1996, 2003~2004) 낙엽량 측정을 위한 최소 필요 표본수를 알아보았다. 임분별 최소 필요 표본수는 오차범위 10%에서는 현재의 15개 트랩수와 비슷했으나, 1994년과 1995년은 타 년도에 비해 약 2배인 30개의 트랩수가 필요하였다. 오차범위 20%에서는 5년간 13개 모든 임분에서 필요한 트랩수는 10개미만으로 나타났다. 임분별로 최소 필요 표본수는 차이가 있었는데 특히 경사가 급하고 해발고도가 높은 임분에서 더 많은 트랩이 설치되어야 하며, 임분 연령이나 낙엽량과는 관계가 없음이 나타났다. 결론적으로 낙엽량 측정을 위한 최소 필요 표본수를 산정할 경우, 본 연구에서와 같이 다년간의 샘플링이 필요하며, 임분의 지형적 특성 역시 고려해야 함을 알 수 있었다.

• Asian-Australasian Journal of Animal Sciences
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• 제31권6호
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• pp.842-850
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• 2018

Objective: Several studies have reported the development of new molecular methods for the prognosis and diagnosis of male fertility based on biomarkers aimed at overcoming the limitations of conventional male fertility analysis tools. However, further studies are needed for the field application of these methods. Therefore, alternative methods based on existing semen analysis methods are required to improve production efficiency in the animal industry. Methods: we examined the possibility of improving litter size in various pig breeds using combined Hoechst 33258/chlortetracycline fluorescence (H33258/CTC) staining. The correlation between field fertility and capacitation status by combined H33258/CTC staining in different ejaculates spermatozoa (n = 3) from an individual boar (20 Landrace, 20 Yorkshire, and 20 Duroc) was evaluated as well as overall accuracy. Results: The acrosome reacted (AR) pattern after capacitation (%) was positively correlated with the litter size of Landrace, Yorkshire, and Duroc pigs and the overall accuracy was 75%, 75%, and 70% in Landrace, Yorkshire, and Duroc pigs, respectively. The difference (${\Delta}$) in AR pattern before and after capacitation was positively correlated with the litter size of Landrace, Yorkshire, and Duroc pigs and the overall accuracy was 80%, 65%, and 55% in Landrace, Yorkshire, and Duroc pigs, respectively. However, the difference (${\Delta}$) in capacitated (B) pattern before and after capacitation was negatively correlated with the litter size of Landrace pigs and the overall accuracy was 75%. Moreover, average litter size was significantly altered according to different combined H33258/CTC staining parameters. Conclusion: These results show that combined H33258/CTC staining may be used to predict male fertility in various breeds. However, the selection of specific efficiency combined H33258/CTC staining parameters requires further consideration. Taken together, these findings suggest that combined H33258/CTC staining may constitute an alternative method for predicting male fertility until such time as fertility-related biomarkers are further validated.

• Asian-Australasian Journal of Animal Sciences
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• 제18권10호
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• pp.1375-1378
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• 2005

The objective of this study was to investigate polymorphisms of BMPRIB (bone morphogenetic protein type IB receptor) gene and its effect on litter size traits in sheep. Three populations including 101 Small Tailed Han sheep, 79 Poll Dorset and 81 hybrids (Poll Dorset${\times}$Small Tailed Han sheep) were used to detect the polymorphisms in exon 6 region of sheep BMPRIB gene. A fragment of approximately 190bp was amplified by one pair of primers, the polymorphism was revealed from the analysis of three populations by the technique of PCR -SSCP, and a mutation from A to G at 746 of the coding region was confirmed by sequencing in several individual. Statistical results indicated the distribution of allele B (with a A$\longrightarrow$G mutation) and A (without mutation) or genotype AA, AB and BB frequencies differed in three populations. BB genotype (44.55%) and B allele (66.34%) frequencies of Small Tailed Han sheep were higher than those of the others. Analysis of variance showed that the polymorphism of BMPRIB gene was associated with positive effect on litter size traits. The means of genotype BB and AB were about 1.04 and 0.74 more than genotype AA for litter size (p<0.05). Analysis of BMPRIB genotype effects on litter size in three populations indicates the existence of genotype BB or B allele increases the litter size. It suggested that the polymorphism in exon 6 (at 746 in the coding region) of sheep BMPRIB gene may be used as a marker for early selection of prolificacy in sheep.

• 한국수정란이식학회지
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• 제8권2호
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• pp.97-103
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• 1993

This study was conducted to determine the main effects of the parity and farrowing season on gestation length and newborn pigs on the basis of the data obtained from 234 litters of Landrace breeds raised at an integrated swine farm in Kyunggy province from January 1991 to December 1992. The results obtained are summarized as follows ; 1. The average gestation length was 115.37 days, and 114.64 days of 8th parity and over was shorter than those of other parities. 2. The averages of litter size and litter size alive per sow were 9.91 and 9.50 heads. The litter size horn at 1st parity was smaller than at other parities, and the litter size in spring was larger than in summer, autumn or winter. 3. The averages of birth weight per litter and pig were 13.53 kg and 1.37 kg. The effect of farrowing season for each litter weight(p<0.01) and pig weight(p<0.05) at birth was significantly higher in spring than other seasons. 4. Incidence of malformation and stillbirth at birth was 4. 10%, and it at 8th parity and over showed the highest rate(7.50%).

• 한국토양동물학회지
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• 제2권2호
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• pp.83-91
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• 1997

One year study with litter bags(mesh size - 0.4mm, 0.8mm, 1.7mm and 5.0mm) was carried out to investigate the soil invertebrate community in the process of leaf decomposition in Namsan and Kwangreung deciduous forests, which were considered to be under different degrees of environmental selective pressure. Soil animals collected from litter bags were classified into the class of order or higher taxa. Acari and Collembola were major groups: Acari and Collembola were about 60% and 30% of total soil animals in their numbers, respectively. Among minor groups, Dipteria, Araneae, Diplopoda, Coleoptera and Chilopoda were comparatively dominant. In Namsan forest which was considered to be under higher environmental selective pressure than Kwangreung, the densities of Acari and Collembola were somewhat higher than in Kwangreung, although there was no statistically significant difference between two sites. The densities of Chilopoda, Enchytraeidae and Nematoda were much higher in Namsan than in Kwangreung but Diplopoda and Symphyla were much more in Kwangreung. It was expected that those groups could be used as bioindicators. The densities of Acari and Collembola were very low until March and then showed the peak in May. But they decreased slowly until November. There was no significant difference among the mesh sized of litter bags in the densities of Acari and Collembola but other groups of soil invertebrates seemed to be prevented from immigrating into the litter bag of mesh size 0.4mm. Decomposition rate of litter in the litter bag was low in early stage of decomposition. The % residual mass over initial mass at 8 months after litter bag introduction in the field was over 80%. Thereafter, % residual mass decreased more fast and was about 60% at 1 year after bag introduction. There was little evidence for the effects of soil invertebrates upon the litter decomposition in the period of this study. And there was no significant difference between Namsan and Kwangreung or among mesh sizes of litter bags in the decomposition rate.

• 대한원격탐사학회지
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• 제30권3호
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• pp.351-366
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• 2014

The aim of this study was to develop software for beach litter detection that includes a Graphical User Interface (GUI) and uses images taken by a micro-unmanned aerial vehicle. Videos were taken over Doomo pebble beach, Sogye pebble beach, and Heungnam sand beach on the northeast coast of Geojedo (Geoje Island), Korea. Still images of actual beach litter were obtained from the videos. The image processing involved preprocessing, morphological image processing, and image recognition. Comparison with still images showing beach litter demonstrated that the software could generally detect litter larger than 50 cm in size such as Styrofoam buoys and circular fish traps (excluding small pixel-size ropes). Combining the proposed method with the conventional surveying approach is expected to enhance the accuracy of beach litter detection. The new technique will also aid in predicting the amount of beach litter generated along coastlines, which is currently difficult to monitor.

• Reproductive and Developmental Biology
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• 제35권3호
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• pp.247-250
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• 2011

본 연구는 국립축산과학원에서 조성한 대요크샤종 및 랜드레이스종 근교계통돈 86두에 대해 산지수에 관여하는 유전자로 알려진 PRLR3, FSR, RBP4 후보유전자 3종의 유전적 다형성을 분석하여 이들 후보유전자와 총산자수의 표현형 및 육종가 간의 연관성을 검증함으로써 경제형질과 관련된 유용표지인자 활용 방법을 개발하고자 수행하여 유전적 다형성을 확인하였다. 대요크샤종에서는 PRLR3, RBP4 후보유전자의 AA형 유전자 빈도가 낮게 나타났으나 이들 모두 다형성을 보였고, 이중 PRLR3 후 보유전자는 B대립유전자가 유의적인(p<0.05) 연관성을 가지고 있었으며, RBP4 후보유전자 역시 유의적인 차이는 없었지만 B대립유전자가 연관성을 가지고 있는 것으로 추정되었다. 랜드레이스종에서 PRLR과 FSR 후보유전자는 다형성이 나타나지 않았으며, RBP4 후보유전자에서 BB형 유전자 빈도가 낮게 나타났으나 다형성을 보였고, 유의적인 차이는 없었으나 A대립유전자가 총산지수의 표현형 및 육종가와 연관성을 가지고 있는 것으로 추정되었다. 본 연구 결과를 활용하여 유의적인 후보종돈을 선발할 경우 번식 능력의 향상에 효과적일 것으로 판단된다.

• Asian-Australasian Journal of Animal Sciences
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• 제17권5호
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• pp.598-602
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• 2004

The Tongcheng pig breed is a famous Chinese indigenous breed. The Ministry of Agriculture of China has filed it as 1 of 19 national key conservation breeds selected from more than 100 Chinese indigenous pig breeds in 2000. In order to improve the reproductive performance, it has been intensively selected to increase the litter size for about 10 years. The population randomly sampled from conservation nucleus of eight families in the Tongcheng pigs was genotyped for identification of their estrogen receptor locus polymorphisms with the PCR-RFLPs method. Only AB heterozygotes and BB homozygotes were detected, and $X^2$ test demonstrated that the locus was in disequilibrium at a significant level (p<0.05). In the present paper, the litter sizes in different parities were regarded as different traits. Holistic status of other unspecific and unidentified genes was estimated by using the statistical methods. Coefficients of kurtosis and skewness showed that the litter size still presented segregating characteristic in the 2nd, 5th, 7th, 8th and 9th parities. Analysis of homogeneity of variance between families confirmed the results for the 5th, 7th and 8th parities. The heritability of litter size for the 1st to 10th parities was estimated with paternal half-sib model and individual estimated breeding values (EBVs) were evaluated by a single trait animal model as well. We found that the averages of EBVs for litter size in each parity did not differ significantly between genotypes, despite the significant difference for original phenotype records in the 3rd, 4th and 5th parities (p<0.05 or p<0.01). The results may be explained by the deduction that the polymorphisms of ESR locus are no longer the important genetic base of litter size variation when the frequency of allele B accumulated in the experience of selection procedure, and further conferring that there exist special genes associated with litter size in the recent Tongcheng pigs population can be made.

• 한국수정란이식학회지
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• 제30권2호
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• pp.91-97
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• 2015

Amphiregulin (AREG), a glycoprotein that is a member of the epidermal growth factor (EGF) family, is expressed by the porcine conceptus and endometrium. AREG genotypes were determined based on an SNP in the intron 3 of the gene. Contradictory effects of AREG genotypes on reproductive traits in different pig breeds were reported previously. G allele had undesirable effect on reproductive trait in Meishan breed, while it had favorable effects in Polish Landrace and Large White. We determined AREG genotypes of 179 pigs including the Duroc, Landrace, Yorkshire, Korean native pig (KNP), and Meishan breeds. Two new SNPs were identified near the previously reported SNP in the intron 3 of AREG. Frequencies of AREG alleles among the Duroc, Landrace, Yorkshire, and KNP sows were significantly different (p<0.001), indicating association between AREG genotypes and pig breeds. The first parity litter size was significantly affected by the breeds (p=0.014), but not by AREG genotypes (p=0.148). However, there were breed and AREG genotype associated trends in the first parity litter size. The first parity litter size appeared to be higher in Duroc and KNP sows with G allele, while it appeared to be lower in Landrace sows with G allele. Significant variability of AREG alleles among pig breeds, for the first time in Duroc and KNP sows, was identified. AREG genotypes may influence reproductive traits differentially for each breed and thus, AREG genotypes may need to be considered when sows are bred to increase litter size.

• 대한수의학회지
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• 제39권6호
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• pp.1161-1167
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• 1999

To investigate the effect of diazepam on fetal development in pregnant rats, this experiment was performed in eighty Sprague-Dawley female rats which were 8 weeks old and grouped into two according to different diazepam treatment period during 5-9 days of gestation and 10-14 days of gestation. Both experimental groups were included by saline treated groups (control) and diazepam-treated groups (6mg, 12mg and 24mg), respectively. Diazepam was injected to pregnant rats subcutaneously, which were sacrified on 20 days of gestation and mean litter size, fetal body weight, fetal crown-rump length (CRL) and pathological findings were examined. 1. Concerning mean litter size, diazepam-treated groups showed lower mean litter size than control in both 5-9 days and 10-14 days of gestation groups(p < 0.05) without difference according to dosage of diazepam and day of gestation. 2. Concerning fetal body weight, diazepam-treated groups during 5-9 days of gestation showed lower fetal body weight than control and the other treated group during 10-14 days(p < 0.01) without difference according to dosage of diazepam. Diazepam-treated group during 10-14 days of gestation showed no difference among experimented groups. 3. Concerning fetal crown-rump length (CRL), diazepam-treated groups during 5-9 days of gestation showed shorter CRL than control and the other treated group during 10-14 days of gestation(p < 0.01) without difference according to dosage of diazepam. 4. Reduction of mean litter size, fetal body weight and CRL was shown from when treated by the dosage of 6mg/kg of diazepam. 5. Maternal mortality according to dosage of the 20mg/kg of diazepam were 30% and 20% in the treated group during 5-9 days and 10-14 days of gestation, respectively. These results indicated that diazepam treatment in pregnant rats caused considerable reduction of mean litter size, fetal body weight and fetal crown-rump length when treated during 5-9 days of gestation.