Purpose The Jeju black cattle are a type of traditional Korean native cattle with a characteristic black fur that covers the entire body. The Jeju black cattle are rare breed and designated as national natural monuments in 2013. It is necessary to improve reproductive techniques for the preservation and proliferation of Jeju black cattle. Methionine acts as a precursor amino acid for glutathione in protection of cells from oxidative damage, and plays a vital role in detoxification. Low sperm motility causes infertility because when sperm do not have progressive motility, it was unable to reach the ovum. The purpose on this study was to investigate whether intake of L-methionine improves sperm motility and fertility. Materials and Methods 6 Jeju black cattles over 10 years of age are raised in Subtropical Livestock Research Institute, National Institute of Animal Science, RDA. 6 Jeju black cattles was fed with L-methionine with 10g/day during 6 weeks. Semen of Jeju black cattle were collected by artificial vaginal technique. Collected sperm was diluted with AndroMed® extender and cryopreserved in 0.5 ml French straws. Fresh and freeze-thawed sperm viability and motility were evaluated by CASA. Results The viability and progressive motility of fresh spermatozoa(live spermatozoa means: from 74.41% to 80.22%, progressive motility means: from 80.60% to 95.40%) and freeze-thawed spermatozoa(live spermatozoa means: from 51.26% to 62.05%, progressive motility: from 29.68% to 45.44%) incresed after L-methionine ingestion. Conclusion The intake of L-methionine in genetically valuable cattle over 10 years of age seems to be useful for improving sperm function.

To investigate the adhesion effect of various kinds and contents of polymeric methylene diphenyl diisocyanates (pMDIs) on adhesion performance, wood adhesives (A-1~5) were synthesized and characterized. As results, when the amount of pMDI increased in adhesives, the dry tensile strength was found to be proportionally increased sustaining at around 16.0~21.6 kgf/cm2. The polyurethane (PU) resin, which used M11S as a source of pMDI showed the best wet tensile strength at 11.9 kgf/cm2 and cyclic boil tensile strength at 8.1 kgf/cm2, which satisfied the requirement of over 7 kgf/cm2. Thermal properties of the rice powder (RP) based polyurethane resins were characterized by differential scanning calorimetry (DSC) and Thermal gravimetric analysis (TGA). Thermal stability of polyurethane resins increased to 250℃ with adding pMDIs. The more pMDI (M5S) was added to adhesive, the higher thermal stability of the resin was observed by TGA.