• Journal of Animal Science and Technology
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• v.49 no.5
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• pp.677-688
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• 2007

돼지를 포함한 대부분의 동물은 일정한 발정주기를 가지고 일정한 시기에 배란을 하는 자연배란동물이지만, 토끼, 고양이, 밍크 등의 암놈은 교미자극에 의해 배란이 일어나는 유기배란동물이다. 또한 1년에 한 번만 발정하는 단발정동물과 1년에 수차례 발정하는 다발정동물이 있다. 이 중에서 모돈은 1년에 수차례 발정하는 다발정 동물로서 발정기에 들면 비발정기와는 다른 행동을 나타낸다(Diehl 등, 2001). 양돈가의 수익을 최대화하기 위해서는 비생산일수를 최소로 줄여야 한다. 모돈의 비생산일수를 줄일 수 있는 한 가지 방법은 성공적으로 교배를 시키는 것이다. 이처럼 성공적으로 교배를 시키기 위해서는 수정적기를 정확히 예측해야 한다. 만약 수정적기를 정확히 판단하지 못하여 수태가 되지 않으면, 비생산일수가 늘어나 손실을 입게 된다. 따라서 수정적기를 정확히 판단하는 것은 모돈의 성공적인 인공수정에 있어서 중요한 요소이다. 수정적기는 배란이 일어나기 전 10시간에서 12시간 사이이며, 발정이 시작되는 시점을 기준으로 하였을 때 경산돈의 경우 26시간에서 34시간 사이이고 미경산돈의 경우는 18시간에서 26시간 사이이다(Evans 등, 2001). 현재 하루에 두 번 모돈의 발정을 확인하는 것이 일반화되어 있으며, 이 때 웅돈을 접촉시키거나 육안관찰을 통하여 발정 유무를 판단한다. 이러한 방법에는 숙련된 기술과 풍부한 경험이 요구될 뿐만 아니라 총 소요노동력의 30% 정도가 요구된다(Perez 등, 1986). 하루에 두 번밖에 발정을 감지하지 않기 때문에 발정이 언제 시작되었는지를 정확히 알 수 없으며, 또한 발정의 대부분이 새벽에 시작되므로 수정적기를 정확히 판단하기란 매우 어렵다. 만약 발정을 감지했더라도 적기에 인공수정을 하지 못한다면, 수태율이 낮아지므로 경제적 손실이 초래된다. 현재 이러한 문제점 때문에 2회에서 3회에 걸쳐 인공수정을 하고 있으나 이에 따른 소요비용과 소요노동력 등은 양돈가의 부담을 가중시키는 요인이 되고 있다. 돼지는 발정기가 되면 비발정기에 나타내지 않던 외음부의 냄새를 맡는 행동, 귀를 세우는 행동 및 승가허용 행동 등을 나타낸다(Diehl 등, 2001). 또한 돼지는 비발정기에 비하여 발정기에 더 많은 활동량을 나타낸다(Altman, 1941; Erez and Hartsock, 1990). Freson 등(1998)은 스톨에서 개별적으로 사육되고 있는 모돈의 활동량을 적외선센서를 이용하여 측정함으로써 발정을 86%까지 감지하였다고 보고하였다. 그러나 이 연구는 단지 모돈의 발정을 감지하였을 뿐 번식관리에 있어서 가장 중요한 수정적기의 판단 기준을 제시하지 못하였다. 따라서, 본 연구는 스톨에서 사육되는 모돈의 활동량을 측정함으로써 발정시작시각을 감지하고 이를 기준으로 인공수정적기를 예측할 수 있는 인공수정적기 예측 장치를 개발한 후 이의 성능을 농장실증실험을 통하여 시험하고자 수행되었다.

• Analytical Science and Technology
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• v.27 no.1
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• pp.34-40
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• 2014

SPLITT fractionation (SF) allows continuous (and thus a preparative scale) separation of micronsized particles into two size fractions ('fraction-a' and 'fraction-b'). SF is usually carried out in a thin rectangular channel with two inlets and two outlets, which is equipped with flow stream splitters at the inlet and the outlet of the channel, respectively. A new large scale splitter-less gravitational SF (GSF) system had been assembled, which was designed to eliminate the flow stream splitters and thus is operated by the full feed depletion (FFD) mode (FFD-GSF). In the FFD mode, there is only one inlet through which the sample is fed. There is no carrier liquid fed into the channel, and thus prevents the sample dilution. The effects of the sample-feeding flow rate, the channel thickness on the fractionation efficiency (FE, number % of particles that have the size predicted by theory) of FFD-GSF was investigated using industrial polyurethane (PU) latex beads. The carrier liquid was water containing 0.1% FL-70 (particle dispersing agent) and 0.02% sodium azide (used as bactericide). The sample loading rate was varied from about 4 to 7 L/hr with the sample concentration fixed at 0.01%. The GSF channel thickness was varied from 900 to $1300{\mu}m$. Particles exiting the GSF channel were collected and monitored by optical microscopy (OM). Sample recovery was monitored by collecting the fractionated particles on a $0.45{\mu}m$ membrane filter. It was found that FE of fraction-a was increased as the channel thickness increases, and FE of fraction-b was increased as the flow rate was increased. In all cases, the sample recovery has higher than 95%. It seems the new splitter-less FFD GSF system could become a useful tool for large scale separations of various types of micron-sized particles.

• Journal of Life Science
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• v.30 no.3
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• pp.313-319
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• 2020

Recently, cattle epidemic diseases are caused by a pathogen such as a virus or bacterium. Such diseases can spread through various pathways, such as feed intake, respiration, and contact between livestock. Diagnosis based on the ELISA (Enzyme-linked immunosorbent assay) and PCR (Polymerase chain reaction) methods has limitations because these traditional diagnostic methods are time consuming assays that require multiple steps and dedicated equipment. In this review, we propose the use of the CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) Cas system based on DNA and RNA levels for early point-of-care diagnosis in cattle. In the CRISPR/Cas system, Cas effectors are classified into two classes and six subtypes. The Cas effectors included in class 2 are typically Cas9 in type II, Cas12 in type V (Cas12a and Cas12b) and Cas13 in type VI (Cas13a and Cas13b). The CRISPR/Cas system uses reporter molecules that are attached to the ssDNA strands. When the Cas enzyme cuts the ssDNA, these reporters either fluoresce or change color, indicating the presence of a specific disease marker. There are several steps in the development of a CRISPR/Cas system. The first is to select the Cas enzyme depending on DNA or RNA from pathogens (viruses or bacteria). Based on that, the next step is to integrate the optimal amplification, transducing method, and signal reporter. The CRISPR/Cas system is a powerful diagnostic tool using a gene-editing method, which is faster, better, and cheaper than traditional methods. This system could be used for early diagnosis of epidemic cattle diseases and help to control their spread.

• Korean Journal of Poultry Science
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• v.42 no.1
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• pp.51-59
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• 2015

Chickens are exposed to the external and internal stressors such as low and high temperature, high stocking density, feed restriction and disease. There have been a few studies on gene expressions through the investigation of chickens under direct exposure to the stress of high stocking density. The objective of the present study was to determine the expressions of genes associated with stress, endoplasmic reticulum (ER)-stress, lipid and glucose metabolism in two strains of chickens, Korean Native Chicken (KNC) and White Leghorn (WL), raised in high stocking density. A total of 164 chickens aged 40 weeks were randomly allotted to a $540cm^2/bird$ stocking density (control), whereas the chickens in a high density group were assigned in a $311cm^2/bird$ stocking density with feeding ad libitum for 10 weeks. Total RNA was extracted from the live for qRT-PCR. The expression levels of hsp70 and $hsp90{\alpha}$ were higher in WL subjected to stress with high stocking density compared with those genes in control (P<0.05), while the expressions of genes were not affected in KNC. ER stress marker gene XBP1 was also highly expressed in WL with stress (P<0.05), but the stress of high stocking density did not influence to ER stress marker genes in KNC. Lipid metabolism associated genes including FABP4, FATP1 and ACSL1 were highly expressed in WL compared with KNC when subjected to high stocking density stress (P<0.05). The expression of glucose transport gene GLUT2 and GLUT8 were increased in chickens exposured to the stress of high stocking density (P<0.05). The data indicate that WL is more sensitive to the stress of high stocking density compared with KNC and the stress may influence the modulation of lipid and glucose metabolism in the liver of chickens.

• Korean Journal of Environmental Agriculture
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• v.19 no.4
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• pp.339-344
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• 2000

Utilization of animal excreta in aquaculture can have potentials of high fish production and low maintenance costs for fish farming and it can reduce water pollution caused by animal waste disposal. Integration of wastewater treatment pond system with aquaculture has been utilized in many countries. Ecologically balanced pond ecosystem is formed through the stabilization of wastes, the growth of aquatic plants, and the cultivation of fish. The most appropriate fish for rearing in these ponds are those which can feed directly on phytoplankton, especially algae. Carp were introduced into a tertiary pond - water depth of 2.2 m, water surface area of $130\;m^2$, volume of $148\;m^3$ - of a pond system treating milk cow excreta. The carp production was $125g{\cdot}m^{-2}year^{-1}$ which falls into upper range of $18\;-\;137g{\cdot}m^{-2}year^{-1}$ of treated sewage-fed carp farming of other countries. Average $BOD_5$ and T-N of the pond was 19.8 and $21.0\;mg{\cdot}L^{-1}$ respectively, and the ecological environment of it was suitable for growth of carp. Several carp of 100g were introduced in August into a secondary pond of the treatment system, whose average $BOD_5$ and T-N was 27.9 and $30.8\;mg{\cdot}L^{-1}$ respectively. They were died within one week, which may be attributed to the depletion of dissolved oxygen at dawn. Effluents from primary treatment can be used in fish pond with dilution and those from secondary treatment can be directly funnelled into it. Waste stabilization pond treating animal excreta can be utilized for fish rearing when its water quality maintains secondary treatment level.

• Korean Journal of Poultry Science
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• v.40 no.4
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• pp.305-313
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• 2013

The objective of this study was to investigate occurrence patterns of Clostridium perfringens on different raising periods in broilers. In different raising periods, we investigated the change in the gross lesion and microscopic histological findings of the mucose of the small intestine, colony forming unit (CFU) and the types C. perfringens with PCR assay. According to the gross lesions on the mucose of small intestine with 10-days-old broilers, the non-antibiotic group showed a higher value (0.6) than the antibiotic group (0.0). Whereas 20-days-old broilers with, the antibiotic treatment had a slightly lower value (1.0) than the non-antibiotic group (1.3). In the histological examination on the villi of the small intestine, there was no damage of the villi of the small intestine with 1-day-old broilers in both groups; however, the non-antibiotic group showed a higher value (0.4) than the antibiotic group (0.0) with 10-days-old broilers. In the non-antibiotic group, the CFU of C. perfringens of the fecal samples from the small intestine increased from 10 days of raising broilers and rapidly increase after 20 and 30 days of raising broilers. There was no detection of C. perfringens types with PCR assy in 1-day-old broilers, but we found C. perfringens type A in 10-, 20- and 30-days-old broilers. Although it is possible to raise healthy broilers by using antibiotics, the addition of antibiotics to concentrate feed is prohibited for public health. The results of this study would contribute to proper feeding management through the careful use of antibiotics.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.7
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• pp.820-825
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• 2007

Earthworm casting was the natural fertilizer that contained high concentrations of nutrients such as nitrogen, phosphate and potassium and of over $10^8$ CFU/ml of microorganisms. Greater than 80% of feed was excreted through the fermentation by the intestinal enzyme, after worm had eaten feeds such as fallen leaves and rotten roots under the ground. Also, the soil structure of casting was known to be very efficient in the aspects of the porosity, the water permeability, and deodorizing activities. In this research, the biofilter packed with a biomedia made of casting and waste polyurethane foam, a binder, which helped to improve the durability and perpetuity of casting, was investigated to degrade malodorous hydrogen sulfide gas. The biomedia had no need of extra supply of nutrients and of microbial inoculations. On the beginning of the operations, it showed 100% removal of hydrogen sulfide gas without lag phase. At SV of 50 $h^{-1}$, hydrogen sulfide gas from the outlet of the biofilter was not detected, when inlet concentration increased to 450 ppmv. After that, removal efficiency decreased as increasing inlet hydrogen sulfide concentration. Hydrogen sulfide removal was maintained at almost 93% until inlet concentration was increased up to 950 ppmv, at which the elimination capacity of $H_2S$ was 61.2 g $S{\cdot}m^{-3}{\cdot}h^{-1}$. Maximum elimination capacity guaranteing 90% removal was 61.2, 65.9, 84.7, 89.4 g $S{\cdot}m^{-3}{\cdot}h^{-1}$ at SV ranging from 50 $h^{-1}$ to 300 $h^{-1}$, but was 59.3 g $S{\cdot}m^{-3}{\cdot}h^{-1}$ at SV of 400 $h^{-1}$. The results calculated from Michaelis-Menten equation revealed that $V_m$ increased from 66.04, 88.96, 117.35, 224.15, to 227.54 g $S{\cdot}m^{-3}{\cdot}h^{-1}$ with increasing space velocity in the range of 50 $h^{-1}$ to 400 $h^{-1}$. However, saturation constant$(K_s)$ decreased from 79.97 ppmv to 64.95 and 65.37 ppmv, and then increased to 127.72 and 157.43 ppmv.

• Journal of Animal Science and Technology
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• v.49 no.1
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• pp.41-50
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• 2007

Data from a comparative slaughter experiment with two hundreds of Korean native (Hanwoo) beef steers were utilized to determine net energy and protein requirements for growth (NEg and NPg). Eight randomly selected steers were used in the initial slaughter group of 6 month of age and the remaining steers allocated to treatments within two groups. The restricted groups were fed 1.2 to 1.5% concentrate per kg body weight (BW) in the growing period (6～12 month of age), 1.7 to 1.8% concentrate per kg BW in the early fattening period (13～18 month of age), and concentrate feed ad libitum in the late fattening period (19～30 month of age). Ad libitum groups were fed concentrate ad libitum through the whole period. Rice straw was offered ad libitum for 24 month of two feeding systems. The steers were slaughtered when animals reached every 2 month from 8 to 30 month of age. For all body composition determinations, whole empty body components were weighed, taken each proportional subsample was ground for chemical analysis. Equations developed with the pooled data to predicted NEg and NPg were similar to the equations of Japanese Feeding Standard for Beef Cattle (2000). First equations were developed to predicted NEg; NEg = 0.05332×LBW0.75×DG for restricted treatment and NEg = 0.04912×LBW0.75×DG for ad libitum treatment. Second equations were developed to predicted NPg; NPg = DG × (224.7－0.251×LBW) for restricted treatment and NPg=DG×(210.1－0.214×LBW) for ad libitum treatment.

• Journal of Animal Science and Technology
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• v.44 no.1
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• pp.105-112
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• 2002

In order to investigate the effects of heat treatment of three animal by-products(feather meal, tallow meal, viscera meal) on in situ ruminal degradation characteristics and gastrointestinal availability of dietary crude protein(CP), three ruminally and duodenally cannulated dry Holstein cows were employed. Cows were fed a diet containing 60% concentrate and 40% orchard grass hay, and had free access to water and mineral block. Experimental feeds were processed for 4 hr at 149$^{\circ}C$ in a forced-air oven, and were passed through a 1-mm screen. Degradation kinetics of feed protein in the rumen were fitted to an exponential type model, and intestinal availability was estimated by the mobile nylon bag technique. Effective CP degradabilities in the rumen for feather meal, tallow meal and viscera meal were 30.2%, 75.0% and 56.4% at 5% passage rate per hour(k=0.05), respectively. In addition, heat treatment increased effective ruminal CP degradability on feather meal and viscera meal treatments, whereas decreased in tallow meal treatment(P$<$0.05). Gastrointestinal CP disappearances of feather meal, tallow meal and viscera meal were 56.2%, 18.6%, and 37.9%, respectively. In addition, heat treatment decreased the gastrointestinal CP disappearance on feather meal and viscera meal treatment, but increased in tallow meal treatment(P$<$0.05). Intestinal availability of rumen undegradable protein(A-UDP) was 80.4% for feather meal, 83.8% for tallow meal and 86.9% for viscera meal. In addition, heat treatment increased A-UDP on feather meal and tallow meal treatment, 94.0% and 91.3%, respectively, but decreased on viscera meal treatment, 76.5%(P$<$0.05).

• Journal of Animal Science and Technology
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• v.48 no.4
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• pp.503-512
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• 2006

This study was conducted to investigate the effects of dietary Lactobacillus brevis (3.4×108 CFU/g) supplementation on growth performance, DM and N digestibilities, blood cell counts and fecal odor emission compounds in growing pigs. Ninety six crossbred [(Landrace×Yorkshire)×Duroc] pigs with an initial BW of 24.60±1.28kg were used for 42-d feeding trial according to a completely randomized design. Three corn- soybean meal based dietary treatments included: 1) CON (basal diet); 2) LB1 (basal diet + Lactobacillus brevis 0.2%) and 3) LB2 (basal diet+Lactobacillus brevis 0.4%). There were three dietary treatments with eight replicate pens per treatment and four pigs per pen. Through the entire experimental period, ADG, ADFI and gain/feed had no significant differences among treatments(P>0.05). Nitrogen digestibility was increased in LB1 and LB2 treatments compared to CON treatment (linear effect, P<0.05), however, DM digestibility had no significant difference among all the treatments (P>0.05). The WBC, RBC and lymphocyte concentrations in whole blood were not affected by treatments (P>0.05). Fecal NH3N and H2S concentrations were significant decreased in LB2 treatment compared to CON treatment (linear effect, P<0.05). Fecal VFA (acetic acid and propionic acid) concentration was also reduced in LB2 treatment compared to CON treatment (linear effect, P<0.05). In conclusion, Lactobacillus brevis (3.4×108 CFU/g) supplementation at the level of 0.4% can improve nitrogen digestibility and decrease the concentrations of fecal odor emission compounds in growing pigs.