A study was performed to investigate the effect of reseeding rates of Italian ryegrass (IRG)〔Lolium multiflorum L.〕on its nutritive value and productivity in native grasssland of Jeju region from Oct. 2011 to Jul. 2012. IRG was sown at reseeding rates (0 30, 40 and 50 kg/ha) in native grassland. When IRG was sown, there was no draught and lodging damage. Plant height in treatment 30 kg/ha of reseeding IRG was the tallest at all harvest stages (p<0.05). DM yield in treatment of 30 kg/ha of reseeding IRG was 12,790 kg/ha and increased 2.7 folds as compared to control. However, there was no significant difference among the treatments. The content of neutral detergent fiber (NDF) significantly decreased in treatment of reseeding, compared to control (p<0.05). In general, the content of NDF in second harvest stage was lower than that of control in first harvest stage. The content of acid detergent fiber (ADF) also showed simliar trend as content of NDF. The content of total digestible nutrients (TDN) in treatments of 30 kg/ha and 50 kg/ha of reseeding were approximately 45.2% each. The content of TDN in treatments of 30 kg/ha and 50kg/ha of reseeding increased as compared to 40 kg/ha and control of reseeding (p<0.05). Therefore, it is conclued that reseeding rate of IRG may improve the yield and nutritive values of IRG at 30 kg/ha.

The objective of the study is to assess temperament of a horse based on general temperament test by a questionnaire survey. Five test criteria were identified: gentleness, patience, aggressiveness, sensitivity, and friendliness, each on a 5-point scale. 114 horses bred at the National Institute of Animal Science (NIAS) in 2010, 2011 and 2012. The horses recorded scores of 3.6∼3.9 for gentleness, 3.1∼3.6 for patience, 3.4∼4.0 for aggressiveness, 2.8∼3.2 for sensitivity, and 3.4∼3.8 for friendliness, the overall score for sensitivity the lowest. Horses born in 2012 scored lower than the rest in all five areas at a statistically significant level (P<0.05). By gender, the colts scored higher than the fillies in all five areas, but the discrepancy was not statistically significant. Factor analysis yielded only one factor, and the Cronbach's α value was 0.980 for standardization of Factor 1, indicating a high reliability of internal consistency. The correlation coefficients among the test criteria ranged between 0.85 and 0.91 (P<0.01). The assessment criteria used in this study are expected to provide a useful basis designing a temperament test horses.

This study was carried out to examine a molecular marker system for parentage test in Jeju Black cattle (JBC). Based on the preliminarily studies, we finally selected for construction of a novel genetic marker system for molecular traceability, identity test, breed certification, and parentage test in JBC and its related industrial populations. The genetic marker system had eight MS markers, five indel markers, and two single nucleotide polymorphisms (SNPs; g.G299T and g.del310G) within MC1R gene which is critical to verify the breed specific genotypes for coat color of JBC differing from those of exotic black cattle breeds such as Holstein and Angus. The results showed lower level of a combined non-exclusion probability for second parent (NE-P2) of 4.1202×10-4 than those previously recommended by International Society of Animal Genetics (ISAG) of 5.000×10-4 for parentage, and a combined non-exclusion probability for sib identity (NE-SI) of 2.679×10-5. Parentage analysis has been successfully identified the JBC offspring in the indigenous population and cattle farms used the certified AI semens for production using the JBC-derived offspring for commercial beef. This combined molecular marker system will be helpful to supply genetic information for parentage test and traceability and to develop the molecular breeding system for improvement of animal productivity in JBC population.

This study was carried out to investigate synthetic extender for semen cryopreservation of Jeju Native Black Bull. The semen was collected using an artificial vagina and transported to the laboratory. The semen was diluted 1:1 by Tris-Egg yolk extender and contrifuged in 1,500 rpm for 15 minutes. The supernatant was removed. The pellect was diluted to final sperm concentration of 2×108/ml by doubling in every 30 minutes at 4℃ cold chamber. The semen was equilibrated for 4 hours at cold chamber and packed to 0.5 ml straw. The semen straws were located above 5 cm for 10 minutes. The height and duration affect the freezing speed by temperature. The frozen straw was plunged to LN2. The presented straws were examined the viability and motility after thawed at 37℃ water bath. Frozen-thawed sperm were evaluated sperm viability, membrane integrity and acrosome integrity. Post-thawed sperm viability has been significantly higher (p<0.05) in fresh sperm (93.27±1.62%) than frozen-thawed sperm (73.34±3.27%). However, there were no significant differences between fresh and frozen-thawed dead cell rate (7.35±2.63 vs, 13.71±2.85). In sperm motility, between Triladyl and AndroMed Extender, there was no significant different (72.86±2.83 vs, 81.47±2.48), similarly, the dead cell rates was similar (18.41±3.42% and 17.26±4.25). The results of our study suggest that AndroMed to the freezing extender showed more positive effect on the frozen-thawed spermatozoa in Jeju Native Black bull semen.

The present study was to assess the in vitro viability and sexing rate of bovine embryos. Blastocysts were harvested on day 7～9 day after insemination(in vitro and in vivo), and the sex of the embryos was examined using the LAMP method. Embryo cell biopsy was carried out in a 80 μl drop Ca2+, Mg2+ free D-PBS and, biopsied embryos viability were evaluated after more 12 h culture in IVMD culture medium. The formation of recovered embryo to expanded and hatching stages had ensued in higher of sexed embryo in vivo than in vitro (100% vs. 89%, p<0.05), and in vitro, the rates of degeneration after sexing were significantly (p<0.05) higher in vitro than in vivo(11% vs. 0.0%). The rates of the predicted sex were female 61% vs. 56%, and male 39% vs. 44% in vivo and in vitro, respectively. The rates of survival following different biopsy methods were seen between punching and bisection method in vivo and in vitro (100% vs. 89% and 100% vs, 78% respectively). Biopsy method by punching was significantly (p<0.05) higher than bisection between produced embryos in vivo and in vitro. The present data indicate that with microblade after punching for embryo sexing results in high incidence of survivability on development after embryo biopsy. It is also suggested that LAMP-based embryo sexing suitable for field applications.

Sperm examination is an important tool in estimating the fertilizing capacity of an ejaculate. The number of spermatozoa in a semen dose, morphology and motility are important for the fertilization process. By evaluation of semen, artificial insemination (AI) using high quality of semen can increase fertilization rate. Boar semen is subject to contamination by various pathogens that can result in fertility disorders in sows. Among these pathogens, porcine reproductive and respiratory syndrome virus (PRRSV), porcine parvovirus (PPV), porcine circovirus-2 (PCV-2) are of particular importance and accurate monitoring prior to and during the presence of boars in AI stations is essential. Because of the high risk of dissemination of disease via AI, The absolute goal is to provide pathogen-free semen and this is feasible with the adequate measures. The disease affects boars semen causes a significant reduction quality. In this study we investigated the characterization boar semen in Jeju, interaction of pathogenic virus infection with characterization of boar semen. Forty-two boar semen from 13 farms were investigated. The semen were stored during 5 days at 17℃ and the sperm qualities in the stored semen were analysed. Visual-motility assessment is a tool (Computer- Assisted Semen Analysis) used to determine the quality of boar semen. Percentage of morphologically normal spermatozoa were assessed. PRRS ,PPV and PCV-2 were detected in boar semen using PCR. The motion characteristics in boar semen was showed 68.4±9.1% for motility, 48.6±7.1 μm/s for VAP, 45.3±7.0 μm/s for VSL, 79.1±8.7 μm/s for VCL, 1.3±0.2 μm/s for ALH, 8.3±0.4 Hz for BCF, 93.6±3.5% for STR, 57.9±6.4 % for LIN. The percentage of sperm with abnormal head, midepeice and tail were 0.3±0.7%, 14.4±12.5%, 4.9±6.6%, respectively. Based on the PCR method, PPV was detected in 20 samples (48%). However, PCV-2 and PRRSV were not detected in any cases. Marked differences in motility and morphology between PPV negative and PPV positive semen were not observed. Sperm cell production was not affected by PPV infection. However, slight increases in detached head, coiled tail after infection were observed (p<0.05). The motility of semen in Jeju is similar to case comparing with other regions in Korea. Although PPV in semen was not affected in semen quality, there is the high risk of virus excretion in the semen of Jeju boars. Therefore continuous screening tests for some particular pathogens in boar semen would be warranted.

The objective of this study was to examine effect of ethylene glycol for semen cryopreservation in Korean Jeju Black Bull. The semen was cryopreserved with extenders containing cryoprotectants (7% glycerol and 3%, 5%, 7% ethylene glycol) and packed to 0.5 ml straws. The semen straws were located above 3 cm of liquid nitrogen for 5 min, 5 cm for 10 min and 8 cm for 10 min. And then frozen straw was plunged into LN2. Post-thawed sperm motility, viability and membrane integrity were significantly higher in 5% ethylene glycol (72.5±5.00%, 54.88±0.66% and 46.00±2.40%; p<0.05). Motility and viability were similar between 7% glycerol and 5% ethylene glycol. However, the membrane integrity was significantly higher in 5% ethylene glycol (34.69±4.64% vs 46.00±2.40%; p<0.05). The viability and membrane integrity were significantly higher in 5 cm for 10 min and 8 cm for 10 min than 3 cm for 5 min (viability: 55.81±2.94, 55.19±3.34 vs 47.94±3.48%; p<0.05 and membrane integrity: 44.94±3.51, 46.06±2.25 vs 40.38±1.03%; p<0.05). The percentage of capacitated sperm assessed by CTC staining, percentage of F pattern was higher in 7% glycerol, 5% and 7% ethylene glycol, and AR pattern was significantly higher in 3% ethylene glycol. F pattern was significantly increased in 5 cm for 10 min and 8 cm for 10 min (p<0.05), but AR pattern was significantly increased in 3 cm for 5 min (p<0.05).