• 한국임상수의학회지
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• 제15권1호
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• pp.62-74
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• 1998

In feedlot cattle the abrupt change of diet from roughage to a large quantity of grain for the purpose to improve production often results in increased occurrence of rumen acidosis or acute carbohydrate encouragement enterotoxemia, bloats diarrhea liver abscess and laminitis or robot disease. The common management practice to control these problem is to increase the amount of concentrates in the diet in a stepwise manner until the animals are adapted to a high-grain ration. However this practice requires at least about 3 weeks adaptation period and specially prepared adaptation rations which contain various amount of concentrates. Present experiment was undertaken in order to findout the more simple and rapid adaptation method of cattle to a high grain ration. Nineteen Korean calves aging from four to six month were fed artifical hay (Youngchoun Chuk-Hyup, Korea) which contains 10% of concentrates or alfalfa and rye grass hays for two months and randomly alloted to three experimental groups and two control groups. The experimental group-1 was inoculated by stomach tube for two days with li500 ml/day of ruminal fluid fished from Korean beef cattle that had been previously adapted to a high-energy ration. The experimental group-2 was inoculated by trocalization for two days with the same ruminal fluid. The experimental group-3 was inoculated by trocalization with 1,500 ml/day of bacterial culture which contained 2$\times $10$^{9}$/m1 of Gram-negative bacteria derived from adapted luminal fluid. The two control groups were treated with normal saline solution by the same methods. All animals were fed high-energy ration that contained 80% of grain ad libitum for 30-74 days beginning on the third of the treatment. The effect of the inoculation on the adaptation was observed clinicopathologically with the following results; All of the experimental calves inoculated with the ruminal fluid or Gram-negative bacterial culture derived from adapted cattle did not show any signs of rumen acidosis or other related diseases, while most of the control calves did show diarrhea and bloat and a calf laminitis. The average daily weight gain and feed efficiency of experimental calves were slightly improved compared with control calves. Following the feeding of high-grain rational the pH of the ruminal fluid was lowered in both the experimental and control groups. However severe acidosis with the pH of below 5.0 was observed in only a control group-2. The protozoal number in ruminal fluid was markedly decreased during the high-grain feeding in both the experimental and control calves. However the decrease was mere severe in control calves compared with the experimental calves. The activation of the protozoa were completely disappeared within nine hours at the refrigerator temperature (4"C). No significant differences in heamatological and blood chemical values between the experimental and control calves were recognized. However in one control calf which showed clinically laminitis marked elevations of serum glutamic oxaloacetate transaminase and lactic dehydrogenase activities and a decrease of serum glucose level were observed. From these results it would be concluded the intraruminal transplantation of unadapted calves with the adapted ruminal fluid from cattle previously adapted to a high-energy ration prevents disease problem associated with high-grain feeding and improve weight gain and feed efficiency.ency.

• Asian-Australasian Journal of Animal Sciences
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• 제21권12호
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• pp.1689-1695
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• 2008

Leptin, the hormone product of the obese gene, is secreted predominately from white adipose tissue and regulates feed intake, energy metabolism and body composition. It has been considered a candidate gene for performance, carcass and meat quality traits in beef cattle. The objective of this study was to identify SNPs in the promoter region of the leptin gene and to evaluate the possible association of the SNP genotypes with carcass and meat quality traits in Korean cattle. We identified a total of 25 SNPs in the promoter region (1,208-3,049 bp upstream from the transcription start site) of the leptin gene, eleven (g.1508C>G, g.1540G>A, g.1545G>A, g.1551C>T, g.1746T>G, g.1798ins(G), g.1932del(T), g.1933del(T), g.1934del(T), g.1993C>T and g.2033C>T) of which have not been reported previously. Their sequences were deposited in GenBank database with accession number DQ202319. Genotyping of the SNPs located at positions g.2418C>G and g.2423G>A within the promoter region was performed by direct sequencing and PCR-SSCP method to investigate the effects of SNP genotypes on carcass and meat quality traits in Korean cattle. The SNP and SSCP genotypes from the two mutations of the leptin promoter were shown to be associated with the BF trait. The average BF value of animals with heterozygous SNP genotype was significantly greater than that of animals with the homozygous SNP genotypes for the g.2418C>G and g.2423G>A SNPs (p<0.05). Analysis of the combined genotype effect in both SNPs showed that animals with the AC SSCP genotype had higher BF value than animals with BB or AA SSCP genotypes (p<0.05). These results suggest that SNP of the leptin promoter region may be useful markers for selection of economic traits in Korean cattle.

• 응용통계연구
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• 제11권2호
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• pp.233-246
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• 1998

1995년 가축통계 총조사자료에 기초하여 1998년부터의 향후 5년간의 표본설계를 하였다. 먼저 본 설계에서는 시도별 변이계수가 목표인 점을 고려하여 농가별 사육마리수를 전체사육마리수로 나눈 사육비율을 구한 다음 이를 전수기준과 총화에 이용하였다. 전수농가기준은 전수농가를 제외 한 후 조사구의 축종별 사육비율의 분산이 일정하게 하는 기준을 정하였고, 층화는 네축종중 최 대사육비율이 비슷한 조사구를 complete linkage 방법에 의해 층화하였다. 충의 개수는 층화에 따른 표본개수를 최소화하는 충의 수를 선정하였다. 또한 표본설계과정상의 해결하기 힘들었던 문제점을 열거하였다.

• Asian-Australasian Journal of Animal Sciences
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• 제18권8호
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• pp.1176-1181
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• 2005

This study investigated the effects of restricted suckling (RS) on some physiological and behavioural stress parameters compared to temporal weaning (TW). Twenty Brahman (Bos indicus) cow-calf pairs were assigned to one of two groups: Calves in the RS group were limited to suckle their dams once daily for 30 min during days 30 to 33, while calves in the TW group were removed from their dams during days 59 to 62 postpartum. Heart and respiratory rates, serum cortisol concentration and body temperature were registered in cows and calves. In addition, the number of steps was also registered in calves. All parameters were recorded 24, 48 and 72 h after the beginning of the two treatments, respectively. In TW calves, higher (p<0.05) cortisol concentration and number of steps were recorded in the 1st samples and 1$^{st}$ and 2$^{nd}$ observations, respectively. No difference was found in body temperature between treatments. However, respiration and heart rates differed in the 1$^{st}$ and 2$^{nd}$ observations, respectively. In general, a significant decrease (p<0.05) in these three parameters was observed over time. In cows, no differences were found in cortisol concentration or body temperature between treatments or with time. Heart and respiratory rates were lower (p<0.05) in the TW treatment only 24 h after beginning of treatment. It was concluded that (a) RS resulted in less behavioural and physiological indices of distress compared to TW in calves, although in general, differences were found only in some variables, mainly during the 1$^{st}$ day following start of the treatment, and there in a chance of age effects. (b) Cows were less affected than their young, regardless of the treatment applied.

• 생명과학회지
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• 제25권4호
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• pp.376-384
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• 2015

소의 질을 평가하기 위해서는 중요한 인자인 근육내 지방(또는 마블링)을 조절하는 분자를 연구해야 한다. cDNA microarray를 사용하여 등지방 조직과 최장근의 유전자발현 차이를 비교하였다. 이 연구를 통해, 우리는 한우의 지방조직에 1211개, 근육조직에서 1346개의 특이 유전자를 확인하였다. bovine chip은 지방조직의 920개 유전자와 근육조직의 760개 유전자로 이루어진 1680개의 특이 유전자로 구성되어있다. 이 실험에서 Microarray 분석은 등지방조직(Cy3)과 최장근(Cy5)의 유전자 발현에 있어서 큰 차이를 보여준다. 차이를 보이는 많은 특이유전자 중에서, 12-리폭시게나아제 유전자와 프로스타글란딘 D 합성효소는 근육내 지방의 축적을 조절하는 중요한 효소이다. 본 연구에서, 일반적으로 발현되지만 한우의 근육과 지방 조직에서 차이를 보이는 많은 유전자를 hybridization 분석을 통해 발견하였다. 선택된 유전자의 발현 수준은 반정량적 RT-PCR을 통해 확인하였고, 그 결과는 cDNA microarray와 유사하였다.

• 한국수정란이식학회지
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• 제29권3호
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• pp.283-287
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• 2014

Sexed semen is commonly used for the production of calves of the desired gender. Gender selection is important in animal production industries. For example, female cattle are required for the dairy industry while males are preferred in the beef cattle industry. The present study was to assess the in vivo embryo production efficiency using the semen separated according to sex during superovulation in Hanwoo. Seventy Hanwoo donor cows were flushed on day 7 of estrus cycle with same FSH and artificial insemination by the same technicians. Embryos were recovered on 7 days after the third insemination by flushing the uterus with embryo collection medium. KPN semen straws used artificial insemination contained 20 million sperm (total number 60 million per donor). Sex-sorted semen straws contained 4 million sperm (total number 12 million per donor). The results obtained were as follows: No differences were observed in the efficiency of superovulation rates on KPN semen 87%, and sexed semen 100%, respectively. The mean numbers of total embryos are each $12.58{\pm}8.31$ and $13.25{\pm}7.86$. The mean numbers of transferable embryos, sexed semen were significantly lower than KPN semen ($3.75{\pm}1.98$ vs. $8.23{\pm}6.07$, P<0.05). The rates of unfertilized embryos from superovulation using sexed semen were significantly higher than KPN semen (50% vs. 15%, P<0.05). The rate of degenerated 2-cell embryos from sexed and KPN semen was 60.87% and 11.11%, respectively (p<0.05). In conclusion, these results indicate that superovulation using sexed semen was useful, but efficient embryo production was important to reducing the damage caused by the Flowcytometer-based sperm sorting procedure.

• 농업과학연구
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• 제47권4호
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• pp.1109-1122
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• 2020

The aim of this study was to develop a marbling classification and prediction model using small parts of sirloin images based on a deep learning algorithm, namely, a convolutional neural network (CNN). Samples were purchased from a commercial slaughterhouse in Korea, images for each grade were acquired, and the total images (n = 500) were assigned according to their grade number: 1++, 1+, 1, and both 2 & 3. The image acquisition system consists of a DSLR camera with a polarization filter to remove diffusive reflectance and two light sources (55 W). To correct the distorted original images, a radial correction algorithm was implemented. Color images of sirloins of Hanwoo (mixed with feeder cattle, steer, and calf) were divided and sub-images with image sizes of 161 × 161 were made to train the marbling prediction model. In this study, the convolutional neural network (CNN) has four convolution layers and yields prediction results in accordance with marbling grades (1++, 1+, 1, and 2&3). Every single layer uses a rectified linear unit (ReLU) function as an activation function and max-pooling is used for extracting the edge between fat and muscle and reducing the variance of the data. Prediction accuracy was measured using an accuracy and kappa coefficient from a confusion matrix. We summed the prediction of sub-images and determined the total average prediction accuracy. Training accuracy was 100% and the test accuracy was 86%, indicating comparably good performance using the CNN. This study provides classification potential for predicting the marbling grade using color images and a convolutional neural network algorithm.

• Animal Bioscience
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• 제36권4호
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• pp.591-600
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• 2023

Objective: We aimed to evaluate the efficacy of a modified Double-Ovsynch protocol vs artificial insemination following estrus detection (AIED) for the enhancement of reproductive performance in Hanwoo cattle. Methods: Four hundred twelve Hanwoo cows were allocated to two treatment groups. The first group of cows were administered gonadotropin releasing hormone (GnRH) on Day 36 (±0.6), prostaglandin F_2α (PGF_2α) on Day 46 (8 to 12 days later), and GnRH on Day 49, which was followed by Ovsynch, consisting of an injection of GnRH on Day 56, PGF_2α on Day 63, and GnRH 56 h and timed AI (TAI) 16 h later (modified Double-Ovsynch group, n = 203). The second group of cows underwent AIED (AIED group, n = 209) and were designated as controls. Results: The pregnancy per AI 60 days after the first AI was higher in the modified Double-Ovsynch (68.5%) than in the AIED (56.5%) group, resulting in a higher probability of pregnancy per AI (odds ratio: 1.68, p<0.05). Moreover, cows in the modified Double-Ovsynch group were more likely (hazard ratio: 1.28, p<0.05) to be pregnant by 150 days after calving than cows in the AIED group, and this difference was associated with a lower mean number of AIs per conception (1.27 vs 1.39, p<0.05) and a shorter median interval between calving and pregnancy (72 vs 78 days, p<0.1). Conclusion: The modified Double-Ovsynch protocol, adjusted according to the herd visit schedule, can be readily used to increase the pregnancy per AI following the first AI and to shorten the interval between calving and pregnancy in beef herds.

• 한국축산시설환경학회지
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• 제9권1호
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• pp.1-8
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• 2003

우리나라는 1998년도에 가축 사육두수가 감소되고 축산물 소비가 둔화되는 등 어려운 점이 많았으나 2012년까지 장기전망으로는 가축 사육두수가 축종에 관계없이 완만하게 상승될 전망이다. 분뇨분해에 의한 아산화질소 배출량은 고유의 분뇨처리시설 유형 점유형태에 대한 자료를 가지고 IPCC (2000)에서 제시하는 조건별 $N_2O$ emission factor 적용하여 산출하였으며 기준년도인 1990년도에 3.71 Gg이었으며 2005, 2010, 2015 및 2020년도에 5.84, 6.07, 6.23 및 6.53Gg으로 각각 추정되었고 기준년도에 비해 2005, 2010, 2015 및 2020년도에는 각각 57.4, 63.6, 67.9 및 76.0% 증가할 것으로 전망되었다. 아산화질소 배출을 줄이면 메탄배출이 오히려 증가하는 특성이 있어 아직까지는 아산화질소 배출저감을 위한 수단이 미약한 실정이며 추후 기술적인 검토가 필요하며 IPCC의 고정값을 사용한 것을 고유의 값으로 교체해야 하는 등 배출계수 (emission factor)의 정확도를 제고시켜나가야 한다는 과제를 안고 있다.

• 한국환경농학회지
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• 제24권3호
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• pp.295-302
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• 2005

The nitrogen (N) balance in Korea during 1985-1997 was calculated according to the surface balance method of the PARCOM guidelines and compared with Japanese N balance. The some differences were founded in the coefficients used on calculating N balance in two nations. Of the important parameters, which can make a big difference in balance, N input by organic fertilizers was not included in Korea different with Japanese, due to absence of reliable statistics and then made lower the input. Nitrogen destruction rate from livestock manure was adjusted differently with 15% in Korea but 28% in Japan. There was some difference in the conversion factors of livestock number into manure N quantity in two nations, but the gap was ignoble scale except beef cattle. Our manure N production rate of beef cattle might be evaluated to be so lower than Japanese. Biological N fixation by pulses was very higher in Korea than in Japan but scarcely affect the increase of total N input, due to small cultivation area. In contrast, N fixation rate by free-living organisms in Korean and Japanese wet paddies showed the big difference with 7.6 and $37.0kg\;ha^{-1}\;yr^{-1}$, respectively, and therefore $29.4kg\;ha^{-1}\;yr^{-1}$ of nitrogen was estimated to be more inputted in Japan. Although there are many points to be more specified and improved, still, Korean N balance was very high with $250-257kg\;ha^{-1}$ in the mid of 1990s, which was the second highest level in OECD countries and furthermore increased continuously during the investigation. In contrast in Japan, which has similar fanning system with Korea, N balance was lower with $130-158kg\;ha^{-1}$ and has decreased continuously since 1993. This high N balance was mainly due to a high usage of chemical fertilizers in our intensive fanning system and the fast increment of livestock feeding. Therefore, the more active action to decrease chemical fertilizer utilization and reduce livestock feeding density is required in the government and farmer sides.