The major limiting factor of the reproductive performance on many farms is the failure to detect estrus in a timely and accurate manner. The estrus detection for Hanwoo cows (Bos taurus coreanea) is generally performed by the visual observation which is estimated at about 40% detection rate only. This recurring problem among farmers has motivated the development of various estrus detection aids. The mounting event duration threshold, standing heat event frequency threshold, estrus detection algorithm and so on, are necessarily needed in order to detect the estrus of Hanwoo cows accurately when using some automatic devices. However, they are not yet investigated for Hanwoo cows. Therefore, the objective of this study was to establish a mounting event duration threshold and standing heat event frequency threshold more specifically for Hanwoo breed by discriminating the duration of standing heat mounting from shorter duration spurious mountings which routinely occur in cattle herds. One hundred and fifty Hanwoo cows with an age between 2 to 5 years were used in this study. Cows that were expected to come into estrus within 3days were randomly assigned to each compartment for the estrus group (EG). The heated cows were video recorded for about 24 hours until after post estrus. The results showed that Hanwoo cows can be considered on estrus when it stand immobile during mounted by any other cow in more than or equal to 3.15s and 3.22s in chest-tail head mount (CTM) and head-above back mount (HBM) and that occurs consecutively at least three times within 876.4s interval. The algorithm was also developed using the thresholds of the mount duration, mount interval and consecutive occurrence number.

An experiment was conducted to study effects of abomasal infusions of casein, glucose or starch on milk production and blood metabolites in dairy cows. Four lactating cows (559±41.9kg) fitted with 100 mm ruminal cannulas were used in a 4 × 4 Latin square experiment. The cows were given access ad libitum to grass silage and received 6.2 kg dry matter (DM) of a mixture of rapeseed meal (5.3kg/d DM) and barley grain (0.9kg/d DM) as a basal diet (CON), the basal diet plus intra-abomasal infusions of 270 g sodium caseinate (CAS), 300 g of glucose (GLU) or 243 g of starch (STA) starting at 09:00 h each day. Abomasal infusion of different nutrients did not affect (p>0.05) grass silage intake and rumen fermentation parameters (rumen pH, ammonia N and volatile fatty acids). As unexpected, milk yield and composition data did not differ between CON and the treated groups (p>0.05). Most of plasma amino acids were not significantly (p>0.05) affected by the abomasal infusions of CAS, GLU or STA except for histidine, tryptophan and glycine. Although histidine, known as the first limiting amino acid in dairy cows fed grass silage based diets, was significantly (p=0.003) increased by CAS, we failed to result in a clear increase in milk yield and protein yield. This discrepancy between plasma AA profiles and milk production could be presumably explained by relatively high concentration of total amino acids in the present study (2,039μmol/l).

In present work, amorphous TiCuNi powders were fabricated by mechanical alloying process. Amorphization and crystallization behaviors of the TiCuNi powders during high-energy ball milling and subsequent microstructure changes were studied by X-ray diffraction and transmission electron microscope. TEM samples were prepared by the focused ion beam technique. The morphology of powders prepared with different milling times was observed by field-emission scanning electron microscope and optical microscope. The powders developed a fine, layered, homogeneous structure with milling times. The crystallization behavior showed that glass transition, , onset crystallization, , and super cooled liquid range were 628, 755 and 127K, respectively. The as-prepared amorphous TiCuNi powders were consolidated by spark plasma sintering process. Full densified TiCuNi samples were successfully produced by the spark plasma sintering process. Crystallization of the MA powders happened during sintering at 733K.

The study was conducted to evaluate the effect of drying, curing and freezing on the quality of beef. Three types of dried (without salt = T1, with salt = T2 and salt + spices = T3); three types of cured (salt curing = T4, sugar curing = T5 and brine curing = T6) and three types of frozen beef (0℃ = T7, -10℃ = T8 and -20℃ = T9) were analyzed at different time intervals up to the period of 180 d. Parameters studied were protein, fat, ash, color and cooking loss of beef. All the chemical constituents (protein, fat and ash) were decreased gradually up to 120 d. The decreasing trend was observed rapid after 120 d up to 180 d of preservation. Highest protein loss was found in T7 (11.1%) and the lowest protein loss was found in T6 (3.85%) in 180 d preservation and significant (p < 0.01) differences were observed among the different preservation methods. Highest fat loss was observed in T6 (7.62%) and the lowest fat loss was observed in T2 (3.18%) and the differences were also significant (p < 0.05) among different methods during the experimental period. Spices dried beef showed a brighter color than others and cured beef showed brown color and the intensity of color was reduced gradually with the increasing of storage period. T9 showed the lowest cooking loss among 3 treatments of frozen beef and the differences also significant (p < 0.01) up to 180 d. It might be stated that sugar curing (T5) and spices drying (T3) would be the useful technique of meat preservation in rural areas and freezing (T9) would be used in large scale preservation at urban areas.

The effects of additions/deletions in glycosylated residues of recombinant human EPO (rhEPO) produced in CHO-K1 on their secretion were examined. hEPO cDNA was amplified from human liver mRNA and cloned into the pCR2.1 TOPO. Using overlapping-extension site-directed mutagenesis method, glycosylation sites at 24th, 38th, 83rd, and 126th were respectively or accumulatively removed by substituting its asparagine (or serine) with glutamine. To add novel glycosylation sites, 69 and 105th leucine was mutated to asparagine. Mutant and wild type rhEPO constructs were cloned into the pcDNA3 expression vector with CMV promoter and transfected into CHO cell line, CHO-K1, to produce mutant rhEPO mutant rhEPO proteins. Enzyme-linked immunosorbant assay (ELISA) and Western analysis with monoclonal anti-EPO antibody were performed using supernatants of the cultures showing transient and stable expressions respectively. Addition of novel glycosylation reduced rhEPO secretion dramatically while deletion mutants had little effect except some double deletion mutants (△24/83 and △38/83) and triple mutant (△24/38/83). This fact suggests that not single but combination of changes in glycosyl groups affect secretion of rhEPO in cell culture, possibly via changes in their conformations.

수출 볏짚 제품내에 들어있는 월도 이화명충을 방제하기 위하여 Phostoxin 훈증제를 기온상태에서 들이 프라스틱 chamber를 사용하여 농도 및 처리시간을 달리하여 시험한 결과 다음과 같은 결과를 얻었다. 1. 월동유충은 처리 48시간, 옹은 24시간, 성충은 8시간에서 의 살충율 얻었다. 2. 약제의 사용농도 보다는 처리시간의 장단에 따라서 살충효과의 차이가 있었다.