• Journal of Animal Science and Technology
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• v.50 no.1
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• pp.33-44
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• 2008

The purpose of this study was to estimate the genetic parameters and trend of Landrace and Yorkshire pigs, which were raised on private farms from 1999 to 2005 and tested for their reproductive performance by the Korea Animal Improvement Association. Prior to analysis, records without pedigree or having value with larger than±3×standard deviation for the Total number of born were excluded. The effects of breed and environmental factors were estimated with least square method(Harvey, 1979), and estimation of breeding values and genetic parameters were performed on the data of 1’st litter only with GIBBSF90(Misztal, 2001) which was programmed according to Gibbs Sampling method based on Bayesian Inference by Gianola and Fernando(1986), Jensen(1994) and others. Gibbs sampling was performed 50,000 times for each parameter, and the first 5000 samples were regarded as those in burn-in period and thus, excluded for post hoc analysis. Total number of born and total number of accident were statistically significant(p<0.01) for the breed, farrowing year, farrowing season and parity effects, and the number born alive at birth was statistically significantp<(0.01) for the breed, farrowing year, farrowing season and parity effects. No particular trend was observed in the genetic and phenotypic improvement of the total number of born and number born alive at birth before 2001, when the piglet registration system started, but the tendencies of increasing for the total number of born and number born alive and decreasing for the total number of accident were observed since 2001. Somewhat higher heritability estimates of our study seems to be attributed to the situations that first parity records with poor farrowing performances were used in the analyses and it was impossible to obtain accurate reproductive performance due to the absence of criteria for record keeping at the level of individual farms.

• Korean Journal of Poultry Science
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• v.49 no.3
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• pp.145-156
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• 2022

The effect of paternal telomere length on reproductive performance, relationship between paternal and offspring telomere length, and association between paternal telomere length and offspring production performance were investigated in Korean native chickens. Using 22 paternal chickens and 329 offspring, the paternal reproductive performance such as fertility, embryo mortality, and hatchability, as well as the offspring production performance such as survival rate, body weight, and weight gain were analyzed. Telomere length was analyzed through quantitative fluorescence in situ hybridization using lymphocytes. No significant differences were observed in fertility, embryo mortality, and hatchability between paternal chicken telomere lengths (P<0.05). These results indicate that paternal telomere length had a weak negative correlation with fertility and embryonic death rate but a weak positive correlation with hatchability. The correlation coefficient between paternal telomere length and offspring survival rate was r=0.17 (P>0.05). The group of offspring with long paternal telomeres showed relatively poor growth performance. Moreover, a significant negative correlation was estimated between paternal telomere length and offspring growth performance (P<0.05). The correlation coefficient between paternal and offspring telomere lengths was r=0.075 (P>0.05). In conclusion, there was a weak association between paternal telomere length and reproductive performance, offspring survival rate, and offspring telomere length, respectively. However, paternal telomere length and offspring growth performance showed a negative relationship. Such results could be due to the re-extension of telomere length by telomere reprogramming in the early embryonic stage and the different degree of telomere shortening between individuals with increasing age after birth.

• Korean Journal of Poultry Science
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• v.10 no.2
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• pp.83-89
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• 1983

Sixteen crosses from two strains of White Cornish and White Plymouth Rock were reared seperately on floors and abdominal fat was measured every two weeks interval from two weeks to twelve weeks of age. The abdominal fat weights surgically removed were slightly heavier in female than male. Estimates of general combining ability variances of body weight showed significant at all weeks of age in both sexes but those of abdominal fat weight were significant at 2, 8, 10 and 12 weeks of age in female and 2, 6 and 12 weeks of age in male. In percentage of abdominal fat to body weight, the significant differences were observed at 10 and 12 weeks of age only in female. The specific combining ability variances were significant at 4, 6, 10 and 12 weeks of age in female and 4, 8 and 12 weeks of age in male in body weight. In abdominal fat weight, there were significant differences at 4, 8, 10 and 12 weeks of age in female but no significant differences in male. The specific combining ability variances of percentage of abdominal fat to body weight showed significant differences at 4 and 8 weeks of age in female but no significant difference in male.

• Korean Journal of Animal Reproduction
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• v.25 no.1
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• pp.51-61
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• 2001

This study was conducted to determine developmental ability of reconstructed embryos by nuclear transfer using somatic cell of Korean bull with high genetic value. Fibroblast cells obtained from ear biopsy of the bull were cultured in Dulbecco's Modified Eagle's medium (DMEM) at 37$^{\circ}C$ in air containing 5% $CO_2$. The cummulus-oocyte complexes were collected from slaughterhouse and were matured in vitro for 20 h in TCM 199 culture medium and the oocytes were then enucleated in modified phosphate buffered saline with cytochalasin B. Matured bovine oocytes were enucleated by aspirating the first polar body and metaphase chromatin using a beveled pipette in modified phosphate buffered saline. The ear fibroblast cells were fused into enucleated oocyte by electrical stimulation. The reconstructed oocytes were activated with ionomycine and 6-dimethylaminopurine, and then cultured in CR1aa medium for 7.5 days. Out of 524 bovine eggs reconstructed by nuclear transfer 65.6%(277/422) embryos were cleaved, and 30.7% (85/277) cleaved embryos were developed to the morula to blastocysts. There was no difference of developmental ability in vitro of reconstructed embryos regardless of donor cell passages. In order to determine fate of foreign mitochondria of donor nucleus, the Mito Tracker stained cells were fused into enucleated oocytes. The donor mitochondria were detected early stage of embryos, but disappeared rapidly. The developmental ability of reconstructed embryos was not impaired by Mito Tracker treatments. The results indicate that viable reconstructed embryos can be producted by nuclear transfer using somatic cell of Korean bulls.bulls.

• Korean Journal of Animal Reproduction
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• v.23 no.3
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• pp.229-237
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• 1999

The influence of ascorbic acid (Asc) and ferrous sulfate (Fe$^{2＋}$) on capacitation, acrosome reaction and fertility in vitro was investigated in boar frozen-thawed spermatozoa with or without preincubation. The addition of 0-1.0 mM Fe$^{2＋}$ to sperm suspensions during preincubation increase acrosome reaction (P＜0.05) and oocyte penetration. These increase are also associated with addition of 0~0.5 mM Asc, but the penetration rates were higher in those without than with sperm preincubation. The addition of 0.1 mM Asc than 0.5 mM in medium with Fe$^{2＋}$ were significantly (P＜0.05) higher on acrosome reaction at 2 h after sperm preincubation. No significant differences, however, were observed in penetration rates among the concentrations of Asc. On the other hand, when preincubation medium containing the Asc was supplemented with 0.1mM Fe$^{2＋}$, the percentage of spermatozoa acrosome-reacted were significantly (P＜0.05) higher than in medium wothout Fe$^{2＋}$, on the contrary, the penetration rate was significantly (P＜0.05) low during in-vitro fertilization. These findings indicate some apparent effects of Fe$^{2＋}$ or Asc addition on acrosome reaction and the fertilizing potential by sperm preincubation.

• Korean Journal of Animal Reproduction
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• v.23 no.3
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• pp.213-220
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• 1999

The litter size has been the primary interest of economic traits in pig reproduction. It has been recently shown that insulin-like growth factor-Ⅰ(IGF-Ⅰ) plays roles in establishing pregnancy and in supporting fetal growth and development. But, the effect of serum IGF-Ⅰ on litter size has not been studied. Therefore, this study was conducted to relate serum IGF-Ⅰ concentration with porcine litter size and to investigate the possible connection with estrogen receptor(ER) as a candidate gene for the litter size. Sera during day 45 to 105 of pregnancy were collected from two groups showing high and low litter size and serum IGF-Ⅰ concentration was measured by radioimmunoassay (RIA). IGF-Ⅰ levels in both groups decreased gradually as pregnancy stage proceeded but were not significantly different. Secondly, DNA was extracted from blood and PCR-RFLP was utilized to analyze ER genotypes of pigs in each group, which produced three polymorphic patterns. Based on the ER genotypes analyzed, low litter size group showed higher IGF-Ⅰ concentration than high litter size group. Taken together, the results indicate that the serum IGF system was correlated with steroid system but not with the litter size in pigs. Thus, this study implies that porcine litter size could be determined locally at the ovary level.

• Journal of Life Science
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• v.14 no.1
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• pp.72-81
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• 2004

Sexually matured guppies (Poeiria reticulata) were exposed to TBTCI (0.1, 0.32, 1, 3.2, 10, 25, 32, 50, 75 and 100 $\mug/l$) for 144 hours to determine the bioaccumulation rate and effects on the reproduction and behavior. The ratio of TBT residues to $\SigmaBTs\; (TBT:\SigmaBTs)$ was 67% or higher in all the guppies exposed to TBTCl, and the higher the level of TBTCl exposed, the higher the ratio of TBT:∑BTs, suggesting that the higher the level of TBTCl exposed, the lower the metabolism rate of the fish. TBTCl exposure led to a poor reproductivity and an abnormal sexual behavior in the fish, i.e. a reduced number of the male sexual sigmoid display and of spermatophore in the efferent duct was observed in the fish exposed to 0.1 $\mug/l$ and higher levels of TBTCl, and a decreasing ratio of the testicular spermatophore cyst to the whole germ cell cysts was observed in the fish exposed to 0.32∼10 $\mug/l$)of TBTCl. The reduced ratio of the spermatophore cyst seems to be an effect of the endocrine disrupter inhibiting spermiogenesis. In the fish exposed to 25 $\mug/l$ and higher levels of TBTCl, more serious effects, such as a rapid increase of mortality, the necrosis of most of the germ cells, great damages in Sertoli cells and epithelial cells of the efferent duct, a significant increase of abnormal swimming behavior, and a cessation of feeding were observed, which suggest the acute toxicity of TBTCl inhibiting not only the reproduction and behavior but also the survival of the fish itself.

• Korean Journal of Animal Reproduction
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• v.25 no.4
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• pp.295-304
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• 2001

Characterization of quantitative trait loci (QTL) was investigated in the experimental crosses between Berkshire and Yorkshire breed. A total of 525 F$_2$ progenies from 65 matting of F$_1$ Parents were produced. Phenotypic measurements included average daily gain (ADG), average back fat thickness (ABF), and loin eye area (LEA). To identify the presence of QTL for reproductive performance, birth weight (BWT) and body weight at 16 days (16DAY) were included as indirect trait. QTL segregation was deduced using 8 markers assigned to chromosome 2 (SSC2). Quantitative trait locus analyses were performed using interval mapping by regression under line-cross model. Presence of imprinting was tested under the statistical model that separated the expression of paternally and maternally inherited alleles. To set the evidence of QTL presence, significance thresholds were derived by permutation following statistical tests, respectively. Genome scan revealed significant evidence for three quantitative trait loci (QTL) affecting growth and body compositions, of which two were identified to be QTL with imprinting expression mode near the ICF II gene region. For average back fat thickness (ABF), a paternally expressed QTL was found on chromosome 2 (SSC2). A paternally expressed QTL affecting loin eye area (LEA) was found in the region of SSC2 where evidence of imprinted QTL was found for average back fat thickness (ABF). For average daily gain (ADG), QTL expressed with Mendelian mode was found on chromosome 2 (SS2). Also, QTL affecting average daily gain (ADC), was identified to be expressed with Mendelian express mode.

• Journal of Animal Environmental Science
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• v.15 no.2
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• pp.139-146
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• 2009

This study was carried out to investigate the reproductive and weaned performances in sow farms, which located in Boryeong city, Chungnam. Data surveyed a total of 10,394 litters of sow recorded from April, 2007 to March, 2008 were collected and analyzed. The results obtained were as follows; 1. The average of number of sow and farrowing rate were 314.10 sows and 78.77%, respectively. And then, there was not significant difference among seasons in number of sows, but significant difference among season was found in farrowing rate (p<0.05). 2. The average of litter size at farrowing and at initial sucking were 11.04 and 10.22 pigs, respectively. The significant differences were not all found in litter size among seasons. 3. The number of pigs, age and growth rate at weaning were 9.23 pigs, 25.77 days and 91.48%, respectively. The significant differences among seasons were not found in number of pigs and age at weaning. However, there was significant difference in growth rate at weaning (P<0.05). 4. The average of farrowing rate of sows per year, pigs from sow per year (PSY), and body weight at marketing were 2.25 times, 20.75 pigs, and 110.46 kg, respectively. The significant differences among seasons were not found in farrowing rate per year and weight at marketing, but that was found only in PSY (p<0.05), respectively.

• Journal of Animal Environmental Science
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• v.19 no.2
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• pp.141-148
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• 2013

This study was conducted to evaluate the effect of different housing systems on the performances of sows and their piglets during gestation. A total of 90 sows (Landrace ${\times}$ Yorkshire) were employed into 3 experimental farms to give 3 treatments, stall housing, group housing in either slatted floor or litter floor. Individual sow was used as an experimental unit. Group housed sows were fed with electronic sow feeder during gestation. Performance measures were taken on sows and piglets. Back-fat thickness and body condition score of sows were not affected by housing systems for pregnant sows. There was no difference of estrus interval of pregnant sows between housing systems. The lower number of still-birth was observed in group housing type. The number of wounded sows in slatted floor was remarkably increased compared with sows in litter floor. This study showed that the housing systems could fairly impact sow and piglet performances.