• 한국습지학회지
• /
• 제19권2호
• /
• pp.252-258
• /
• 2017

계류에서 보가 저서성 대형무척추동물 군집에 미치는 효과를 확인하기 위해 도림천 상류에서 계단식 구간(100m 당 3.02개의 보)과 비계단식 구간(100m 당 0.96개의 보)을 나누어 저서성 대형무척추동물을 정성, 정량 조사하였다. 평균 유속은 계단식 구간(0.043m/s) 보다 비계단식 구간(0.149m/s)에서 더 빨랐다. 정수역을 선호하는 파리목(Diptera)는 비계단식 구간(32%)보다 계단식 구간(78.3%)에서 더 많이 출현하였다(p<.05). 유수역을 선호하는 하루살이목(Ephemeroptera)는 계단식 구간(4.5%)보다 비계단식 구간(14.1%)에서 더 풍부하게 출현하였다(p=.203). 날도래목(Trichoptera)는 종에 따라 출현하는 빈도가 다르게 나타났다. 주워먹는 무리(gathering-collector)비계단식 구간보다 계단식 구간에서 1.8배나 많이 출현하였다(p<.05). 반면 걸러 먹는 무리(filtering-collector)는 계단식 구간에서 약 4.4배 더 많이 출현하였다(p=.124). 균등도 지수(J')는 계단식 구간과 비계단식 구간에서 각각 0.41과 0.77로 나타났다. 수환경을 평가하는 데 이용되는 한국오수생물지수 KSI는 계단식 구간과 비계단식 구간에서 각각 4.0과 2.4이었다. 군집의 균형성을 나타내는 EPT/C 지수는 계단식 구간과 비계단식 구간에서 각각 0.1과 0.7으로 나타났다. 본 연구는 저서성 대형무척추동물의 다양성을 유지하기 위해서는 소형보를 계류에 설치할 것을 제안한다.

• 소성∙가공
• /
• 제21권8호
• /
• pp.506-511
• /
• 2012

Aluminum brazing normally requires a careful control of temperature due to the small interval between brazing and melting temperatures for base materials. Unsuitable processing conditions, including brazing temperature outside admissible range, gap between brazed materials or inadequate flux feeding, can lead to joining defects. In this study, A357 was used as a filler metal for the brazing of pure aluminum base materials and brazed at temperatures in the semi-solid state. Interface microstructures with base materials were observed using optical metallography(OM) and scanning electron microcopy(SEM) with energy dispersive spectroscopy(EDS), and compared to conventional aluminum brazing.

• Asian-Australasian Journal of Animal Sciences
• /
• 제14권7호
• /
• pp.970-973
• /
• 2001

An experiment was carried out to assess the effect of feeding concentrate mixtures varying in bypass protein levels with urea-treated or untreated grass on the performance of twelve Red Kandhari calves (14 months of age and 78.15 kg body weight) for a period of 75 days. Dry grass was treated with 4 percent urea solution and ensiled for 30 days. The CP ($N{\times}6.25$) content in urea treated grass increased from 3.96 to 8.89 percent. Two iso-caloric and iso-nitrogenous concentrate mixtures (CM-I and CM-II) varying in RDP to UDP ratio viz., 65:35 and 55.45 were prepared. The calves in control group ($T_1$) were fed concentrate mixture-I with ad libitum untreated dry grass and those in experimental group ($T_2$) were fed concentrate mixture-II with ad libitum urea treated dry grass. The dry matter consumption in group $T_2$ was significantly (p<0.01) higher as compared to group $T_1$. The total DMI in $T_1$ and $T_2$ was 146.92 and 166.95 kg respectively, whereas the DMI per day and per 100 kg body weight was 1.94 and 2.22 and 1.90 and 2.35 kg, respectively. The average total gain in body weight (kg) and average daily gain (g) of calves in $T_2$ was significantly (p<0.01) higher as compared to those in $T_1$ the values being 28.66, 18.33 and 382.16, 244.44, respectively. Feed efficiency in terms of kg DM per kg gain in body weight was significantly (p<0.01) lower in group $T_1$ than in $T_2$. The cost of feed per kg gain in body weight for $T_2$ and $T_1$ group was Rs. 21.14, 28.22, respectively. The digestibility coefficients of DM, CP, EE, CF, NFE, NDF and ADF were 59.60, 57.50, 53.00, 65.04, 45.82, 48.48, 52.48 and 55.73 for $T_1$ group. The coressponding values were 68.78, 67.80, 59.83, 71.41, 49.93, 53.37 and 57.81, respectively for $T_2$ group. The digestibility coefficients for all the proximate principles in $T_2$ were significantly (p<0.01) higher as compared to $T_1$. However, NDF and ADF digestibilities were not significantly different. Nutritive value determined in terms of DCP and TDN for The experimental ration was significantly (p<0.01) higher than control ration, the values being 7.32 and 47.34 and 9.39 and 52.40% respectively. The blood urea nitrogen levels at 0, 3 and 6 h interval after feeding were significantly (p<0.01) lower in calves fed experiment ration as compared to control. The overall results indicated that in Red Kandhari calves an optimum growth can be economically achieved by feeding 4 percent urea treated dry and mature grass as basal roughage supplemented with a concentrate mixture containing 20 percent CP, 70% TDN and 45% UDP/bypass protein.

• Pediatric Gastroenterology, Hepatology & Nutrition
• /
• 제15권1호
• /
• pp.29-37
• /
• 2012

Purpose: To examine the prevalence of $Clostridium$ $difficile$ ($C.$ $difficile$) colonization (CDC) and potential neonatal determinants of CDC in hospitalized preterm infants. Methods: Fecal samples were serially collected within 72 h after birth and at 1, 2, and 4-6 weeks of age from preterm infants in the neonatal intensive care units (NICUs) of two different university hospitals. Total bacterial DNA was extracted from each fecal sample from 49 infants, and polymerase chain reaction (PCR) was performed with primers for the 16S gene of $C.$ $difficile$ and the toxin A and toxin B genes. The correlation between the results of $C.$ $difficile$ PCR assays and the clinical characteristics of the infants was analyzed. Results: The prevalence rates of CDC were 34.7, 37.2, 41.3, and 53.1% within 72 h after birth and at 1, 2, and 4.6 weeks of age, respectively. The toxin positivity rate was significantly higher in the infants with persistent CDC than in those with transient CDC (8/12 [66.7%] vs. 6/25 [24.5%] ($p$=0.001). Among the various neonatal factors, only the feeding method during the first week after birth was significantly associated with persistent CDC. Exclusive breast-milk feeding (EBMF) significantly decreased the risk of persistent CDC compared to formula or mixed feeding (adjusted odds ratio: 0.133, 95% confidence interval: 0.02-0.898, $p$=0.038). Conclusion: The prevalence of CDC increased with the duration of hospitalization in preterm infants in the NICU. EBMF during the first week after birth in hospitalized preterm infants may protect against persistent CDC.

• 한국수정란이식학회지
• /
• 제21권3호
• /
• pp.177-182
• /
• 2006

본 연구는 $MGA+PGF_{2{\alpha}}$ 투여에 의한 발정 동기화 방법이 한우의 혈청 $P_4$ 수준, 발정 발현율과 수태율에 미치는 영향을 규명하고자 수행하였다. 첫째로, 한우 미경산우에서 $MGA+PGF_{2{\alpha}}$ 투여가 혈청 $P_4$ 수준에 미치는 영향을 조사하기 위하여 한우 미경산우 10두 및 프리마틴 1두에 대하여 MGA를 1일 0.5 mg을 14일간 오전 배합 사료에 섞어 급여하였으며, 19일이 경과한 후에 $PGF_{2{\alpha}}$ 25 mg을 투여하였다. MGA feeding 후 혈청 $P_4$ 농도 수준을 분석하기 위하여 MGA 급여 기간과 급여 종료 후 발정이 관찰될 때까지는 3일 간격, $PGF_{2{\alpha}}$ 투여 시, 발정 및 인공 수정 시, 인공 수정 후 15일째 및 2개월째에 혈액을 채취하였다. 한우 미경산우의 혈청 $P_4$ 수준은 MGA급여 7일 이후부터 상승하기 시작하여 투여 9일차에는 5.4 ng/ml로써 이후 상승된 상태에서 유지되었다. $PGF_{2{\alpha}}$ 투여시점인 33일차에는 7.6 ng/ml 수준으로 피크를 나타냈고, 투여 2-3일이 경과하고 발정이 발현됨에 따라 1.4 ng/ml로 급강하하는 양상을 보였다(p<0.05). 그러나 프리마틴의 경우에는 시험 기간 동안 P4수준의 변화가 인정되지 않았다. 둘째로, 한우 미경산우 및 경산우 194두를 이용하여 상기한 $MGA+PGF_{2{\alpha}}$ 투여 방법(n=104)과 대조군으로 $PGF_{2{\alpha}}$ 투여(11일 간격 2회 투여, n=90)에 따른 발정 발현율 및 수태율을 비교하였다. 발정 발현율은 대조군인 $PGF_{2{\alpha}}$ 투여군 72.2%에 비해 $MGA+PGF_{2{\alpha}}$ 투여군에서 91.3%로써 유의적으로 높았다(p<0.05). 인공 수정 후 수태율은 $MGA+PGF_{2{\alpha}}$ 투여군이 $PGF_{2{\alpha}}$ 투여군에 비해 1회 수정 수태율(51.1 vs. 59.6%), 2회 수정 수태율(77.8 vs. 84.6%) 및 전체 수태율(88.9 vs. 94.2 %)이 유의적으로 높았다(p<0.05). 본 연구의 결과는 $MGA+PGF_{2{\alpha}}$를 이용한 발정 동기화 방법은 $PGF_{2{\alpha}}$ 투여법에 비해 높은 발정 동기화율 및 수태율을 나타냄으로서 한우의 번식 능력 향상에 적절히 활용될 수 있음을 보여준다.

• 한국응용곤충학회지
• /
• 제58권3호
• /
• pp.219-224
• /
• 2019

Zophobas morio는 주로 애완동물의 먹이로 사용되고 있으며 대형어, 파충류, 양서류, 조류의 주식 및 간식으로 활용하기도 한다. Zophobas morio는 $27^{\circ}C$ 이상에서 사육하면 부화 후 80일째에 0.6 g 이상의 유충 무게를 얻었다. 보조사료를 선발하기 위해 콩가루, 어분, 보리, 메밀가루를 이용하였을 때 단백질 함량이 높은 콩가루와 어분에서 부화 후 80일째에 0.7 g이상의 유충무게를 확보하였다. Zophobas morio를 대량 사육하기 위해 성충의 산란율 증가와 균일한 유충을 확보하는 기술이 필요하다. 성충의 산란 격리틀을 이동시켜 줌으로써 유충 단계가 혼재되어 선발하는데, 노동력을 줄이며 높은 수확량과 균일한 유충을 확보하기 위해 5일, 10일, 15일 간격으로 성충을 산란틀로 옮겼을 때 5일 간격으로 성충을 옮기는 처리에서 총 부화유충수 7,256마리로 10일 5,439마리, 15일 2,060마리보다 더 많은 유충수를 확보할 수 있다. 따라서 Zophobas morio 성충을 5일 간격으로 산란틀을 옮기면서 산란을 9회 시키면 7,000마리 이상의 유충을 확보할 수 있으며 이때 한 마리당 무게는 0.68 g 확보가 가능하다.

• Reproductive and Developmental Biology
• /
• 제34권3호
• /
• pp.213-216
• /
• 2010

This study was carried out between November 2008 and October 2009 in the experimental farm of Chunnam National University to investigate the effect of feeding of Sudangrass silage on the reproductive performance of Hanwoo cows. Two diets, rice straw or Sudangrass silage separately from concentrate were fed 19 Hanwoo cows. In control group (=CON), cows (n=9) were fed 5 kg (/head) rice straw and 3 kg (/head) commercial diet. In Sudangrass silage group (=SGS), cows (n=10) were fed 12.5 kg (/head) Sudangrass silage and 1 kg (/head) commercial diet. 1. Days to post-partum insemination were $78.8{\pm}25.3$ days for CON and $84.7{\pm}24.6$ days for SGS group and days to post-partum conception in CON or SGS were $90.1{\pm}24.1$ and $87.7{\pm}26.8$ days, respectively. 2. Post-partum conception rates for first service in CON or SGS was 66.7% and 90.0%, respectively, and caving interval was $375.1{\pm}46.7$ days for CON and $370.2{\pm}34.4$ days for SGS group. 3. Body Condition Scores of Hanwoo cows at artificial insemination was 5.36 for CON group and 4.93 for SGS group.

• Journal of Biosystems Engineering
• /
• 제5권1호
• /
• pp.51-57
• /
• 1980

It is desirable to increase the diameter of rice bundle harvested by Japanese reaper binder recently introduced into Korean farmers , since it is too small for stalking in the field for preliminary drying prior to threshing operation which is dominant procedure in rice harvesting . Accordingly, this study was conducted to analyze the effect of the size of rice-bundle on the performance of binder and self-feeding thresher. The results are summarized as follows : 1. The diameter of rice-bundle could be increased from $\phi$80-98 to $\phi$105.0-125.4 while the number of rice bundles per 10 a were reduced to 1200 from 1600. The time required for harvesting 10 a of rice was 81 minutes in small size bundles and 84 minutes in large size bundles and no statistical difference was obtained. 2 .The grain loss due to discharge and cutting were slightly increased with large size bundle compared to the small size but no statistical difference was obtained. The precision of operation and drying rate was not significantly different between small and large size bundles. 3. The unthreshed losses were the same between large and small sizes of rice bundles when self-feeding thresher was used. When 8 PS engine was used , continuous operation was possible for small size bundles , but 1.5seconds of time interval was necessary for large size buldles. 4. The consumption of binding twine was reduced to 603 from 820 meters with the larger bundles , and the labour requirement for stalking rice bundles in the field was also reduced to 1.83 form 2.50 man-hour per 10 a Therefore, harvesting cost can be reduced up to 26.5 percent by increasing the bundle size.

• Asian-Australasian Journal of Animal Sciences
• /
• 제25권5호
• /
• pp.738-748
• /
• 2012

One of the main goals of small, medium and large farms is to improve the reproductive performance of rabbit does. Stocks of lower productivity can be improved by crossing with intensive breeds. A better nutritional status of both foetuses and suckling kits has a positive effect on their later productivity. Overfeeding young females before first mating can lead to conditions of fattiness. Using restricted feeding or higher fibre content in the feed and changing it for a higher level ad libitum feeding about one week prior to first mating leads to longer lifespan and higher productive level. Intensive reproductive rhythm creates a negative energy balance in does : they are unable to consume enough feed (energy) for the nutritional requirements of foetus and lactation, and therefore lose most of their fat reserves. Furthermore, primiparous does also expend energy because they are still growing. Under intensive conditions, the 42-d reproductive rhythm (re-mating 11 days after parturition) is recommended. Under extensive conditions, the 18 or 25-d mating interval with 35 to 42-d weaning could be suitable. On small farms, natural mating is favoured; on large farms AI is commonly employed. The main advantage of AI is the all-in, all-out system. Hormonal (PMSG) treatment is used with AI to increase receptivity on d 11. Frequent and high level PMSG use can lead to higher anti-PMSG antibody rates. Lower level (max. 20 IU) and less frequent PMSG injection or non-hormonal alternative methods (short dam-litter separation, changing nursing method or lighting programs) are recommended for this reason.

• Asian-Australasian Journal of Animal Sciences
• /
• 제22권7호
• /
• pp.1060-1068
• /
• 2009

The buffalo (Bubalus bubalis) is an important contributor to milk, meat, power, fuel and leather production in many developing countries. Buffaloes can be categorized into Asian and Mediterranean buffaloes. Asian buffalo includes two subspecies known as Riverine and Swamp types. Riverine (water buffalo) and Swamp buffaloes possess different genetics (50 vs. 48 chromosomes, respectively), morphology (body frame, body weight, horn shape and skin color) and behavior (wallowing in mud or water) and thus, are reared and used for different purposes. Low per head milk yield, poor reproductive performance (seasonal breeding behavior, anestrous, and longer calving interval) and low growth rate in buffaloes have been attributed to insufficient supply of nutrients. In many parts of Asia, where the buffalo is an integral part of the food chain and rural economy, irregular and inadequate availability of quality feedstuffs and their utilization are hampering the performance of this unique animal. Balanced nutrition and better management can enhance buffalo productivity. Many efforts have been made in the last few decades to improve nutrient supply and utilization in buffaloes. Recent research on locally available feed resources such as crop residues, and industrial by-products, dietary addition of micronutrients, use of performance modifiers and use of ruminally protected fat and protein sources have shown significant potential to improve growth, milk yield and reproductive performance of buffaloes. However, a number of issues, including establishment of nutrient requirements for dairy and beef, development of buffalo calf feeding systems, nutritional management of metabolic and reproductive anomalies, and understanding and exploitation of the buffalo gut ecosystem, need to be addressed. Extensive coordinated research and extension efforts are required for improved buffalo nutrition in developing countries.