Eung-Gi Kwon

Effects of polyclonal antibodies to abdominal and subcutaneous adipocytes on ruminal fermentation patterns and blood metabolites in Korean native steers.

Sixteen ruminally cannulated Korean native steers (Hanwoo; kg) were used to investigate the effects of polyclonal antibodies against abdominal (AAb) and subcutaneous adipocyte membrane proteins (SAb) on ruminal fermentation patterns and blood metabolites. The body weight (BW) of Hanwoo was decreased 2-weeks after AAb and SAb injection, BW reduction was also observed in control and non-immunized serum groups, indicating that stress induced by other factors (e.g. blood sampling etc.) rather than antibodies injection may affect the BW reduction. Antibodies treatment did not affect (P > 0.05) rumen pH, volatile fatty acids and ammonia-N concentration. The ranges were similar with typical ranges of those in Hanwoo. Compared with control, blood urea N concentration was decreased in AAb group and increased (P 0.05) affected at 2- or 4-weeks after the treatment. Concentration of plasma glucose in the non-immunized serum group was significantly higher (P 0.05) between the groups and ranged from 11.4 to 19.9 mg/dl, which is the perfect range of plasma triglyceride of Hanwoo fed concentrate based diets. In conclusion, these results may indicate that the present AAb and SAb have safety in nutritional physiological metabolism in Hanwoo. Further study on in vivo fat reduction of the antibodies against abdominal and subcutaneous adipocytes PMPs of Hanwoo is required for inedible fat-reduced high quality beef production.

Effect of Indigenous Herbs on Growth, Blood Metabolites and Carcass Characteristics in the Late Fattening Period of Hanwoo Steers

This study was conducted to evaluate the effects of indigenous herbal supplements on growth, blood metabolites and carcass characteristics in the late fattening period of Hanwoo steers. In a 6 month feeding trial, thirty Hanwoo steers (647±32 kg) were allotted to one of 5 treatment groups, control (basal diet contained lasalocid), licorice, clove, turmeric and silymarin, with six steers per pen. All groups received ad libitum concentrate and 1 kg rice straw/animal/d throughout the feeding trial. Blood samples were collected at the beginning, middle, and the end of the experiment and the steers were slaughtered at the end. Blood glucose, triglyceride, total protein, and albumin concentrations were higher in the turmeric treatment compared with other treatments. Blood urea nitrogen and creatinine concentrations were highest (p<0.003 and p = 0.071, respectively) in steers treated with silymarin. Alanine aminotransferase activity was lower (p<0.06) for licorice and silymarin compared with the control group. There were no alterations in serum aspartate aminotransferase and gamma glutamyltransferase activities as a consequence of herb treatments (p = 0.203 and 0.135, respectively). Final body weight, body weight gain, average dairy gain and dry matter intake were not significantly different among treatments. Yield grade, marbling score and quality grade were higher for silymarin group than those of the control group (p<0.05). Therefore, the results suggest that silymarin can be used an effective dietary supplement as an alternative to antibiotic feed additive and a productivity enhancer, providing safe and more consumer acceptable alternative to synthetic compounds during the late fattening period of steers.

Effects of Thymol, Eugenol and Malate on In vitro Rumen Microbial Fermentation

The purpose of this study was to investigate effects of increased levels of eugenol, thymol and malate on pH and the concentrations of VFA, lactate and ammonia-N during in vitro ruminal incubation. One Hanwoo beef steer (741 kg) fitted with a rumen cannula was used and fed 0.5 kg/day rice straw and 10 kg/day corn-based concentrate (ratio of concentrate to rice straw = 95 : 5 on DM basis). Three different doses of thymol, eugenol and malate were used. Treatments of the experiment were as follows: Treatments of thymol were control (1g D-glucose/40ml), T1 (1g D-glucose + 40 mg thymol/40 ml), T2 (1g D-glucose + 50 mg thymol/40 ml) and T3 (1g D-glucose + 60 mg thymol/40 ml). Treatments of eugenol were control (1g D-glucose/40 ml), E1 (1g D-glucose + 55 mg eugenol/40 ml), E2 (1g D-glucose + 65 mg eugenol/40 ml) and E3 (1g D-glucose + 75 mg eugenol/40 ml). Treatments of malate were control (1g D-glucose/40ml), M1 (1g D-glucose + 25 mg malate/40ml), M2 (1g D-glucose + 50 mg malate/40 ml) and M3 (1g D-glucose + 100 mg malate/40 ml). The results of this study showed that eugenol and thymol have improved stability of the ruminal fermentation by decreasing lactic acid concentration and increasing ruminal pH. However, it inhibited the production of total VFA, acetate and propionate. Malate also improved stability of the ruminal fermentation by decreasing lactic acid concentration and increasing ruminal pH, but it had a very little effect on ruminal lactate concentrations and pH. On the other hand, malate did not decrease the concentrations of total VFA, acetate and propionate. Therefore, at the low ruminal pH expected in high-concentrate diets, thymol, eugenol, and malate are potentially useful in Hanwoo finishing diets. Further studies are necessary for determining the effectiveness of these additives on in vivo rumen fermentation and animal performance in Hanwoo finishing steers.

Effects of Dietary Barley on the Growth Performance and Carcass Characteristics in Hanwoo Steers

본 연구는 보리의 급여수준 또는 가공 형태가 반추위 내 발효특성과 소화율 및 한우의 성장과 육질에 미치는 효과를 조사하고자 실시하였다. 분쇄보리와 압편보리를 이용하여 반추위 fistula를 장착한 한우암소 4두를 이용하여 4종류 시험사료(옥수수구, Corn; 분쇄보리구, GB; 압편보리구, DRB; 분쇄압편보리구, GDRB)에 대한 소화시험을 수행하였고(시험 1), 아울러 19개월령 거세한우 40두를 공시하여 비육후기 한우 거세우의 보리 급여가 육질에 미치는 효과를 구명하기 위한 사양시험을 실시하였다(시험 2). 시험 1: 보리첨가 시험사료의 소화 및 영양학적 가치 조사1.사료 섭취에 따른 반추위 내 pH의 변화는 GB와 DRB에 비해 Corn 및 GDBR 형태에서 pH의 저하 폭이 더 컸으며, GDRB구는 최저 pH가 5.5까지 떨어져 반추위 내에서 사료분해가 급격하게 이루어지는 경향을 보였다. 2.암모니아농도의 변화는 시험사료에 따른 차이는 없었으나, GR구와 DBR구에서는 꾸준하게 다른 두 처리구에 비해 비교적 낮은 농도로 안정적인 발효환경을 보였다. 시험 2 : 비육후기 한우 거세우의 가공보리 첨가사료 급여에 따른 증체 및 육질 개선효과 1.시험 개시 후 280일이 지난 28개월령의 DRB구 거세한우의 평균 체중이 683kg로 가장 높았고, 분쇄 및 압편보리를 첨가한 GDRB구의 평균 체중이 653.3kg로 가장 낮았다. 2.옥수수구(Corn)와 분쇄보리(GB)를 섭취한 거세한우는 전 기간 비슷한 일당증체를 보였으며, GDRB구의 일당증체가 가장 낮았다. 그러나 DRB 사료를 섭취한 거세한우의 19~23개월령 평균 일당증체가 0.89kg이었고, 24~28개월령 사이에는 0.43kg로 다른 처리구에 비해 높은 증체 효과를 보였다. 3.보리의 가공 형태는 생체중, 냉도체중, 도체율, 등지방두께 및 육량지수 등에 영향하지 않았으나 등심단면적은 분쇄보리를 급여한 GB구에서 92.5cm2로서 현저히 증가되었는데(P 【This study was carried out to determine the effects of processing methods of barley as a proper source of grain in diets of Hanwoo on fermentation pattern in the rumen fluid and digestibility of the diets, the growth performance and carcass characteristics of Hanwoo. The degree of ruminal pH change in the cows fed diets of the Corn(corn basis) and GDRB(ground and dry-rolled barley) tended to be greater than those in the cows fed other two diets (ground barley, GB and dry-rolled barley, DRB). The diet of GDRB showed the lowest ruminal pH(5.5), indicating the rapid degradation of the diet in the rumen. Although ammonia concentration was not affected by diet, the GR and DBR diets maintained the low concentrations of ruminal ammonia compared with other two treatments. And the effects of feeding processed barley grain on body weight gain and meat quality of Hanwoo steers were as follows. Steers fed DRB diet had the highest body weight, 683.0kg at 28 months old, while those fed the GDRB showed the lowest body weight, 653.3kg. The average daily gain(ADG) was similar between the steers fed Corn and GR throughout the whole period, but the GDRB showed the lowest ADG. The steers fed the DRB showed the significant increase in ADG(0.89kg/d from 19 to 23 months old and 0.43kg/d from 24 to 28 months old) compared with those fed other diets. Feeding diets containing corn and/or barley did not influence live body weight, cold carcass weight, carcass yield, back-fat thickness and carcass grade of Hanwoo steers.】

Effects of Mixing Time for Total Mixed Rations using Corn Silage on Ruminal In situ Dry Matter Degradation and Milk Production in Dairy Cows

This study was conducted to evaluate the effect of mixing time for TMR (total mixed rations) mixed with corn silage on particle size, peNDF (physically effective neutral detergent fiber), laceration, and ruminal in situ dry matter degradation. The study also aimed to evaluate the effect of consumption of the TMR on the milk yield and milk components of mid-lactational dairy cows. TMRs were mixed for 30 minutes (T1) and 50 minutes (T2) using the same material. All samples were then analyzed with a Penn State Particle Size Separator (PSPS). The particle size of T1 was significantly lower in the bottom pan (8 mm>) than that of T2 (p 8.0 was significantly higher in T1 (17.18%) than in T2 (13.85%) (p 19 mm), no significant difference was found after 72 hours incubation, although T1 degradation was significantly higher after 24 hours incubation (p<0.01). Milk yield was no different between the groups of cows, whereas the milk fat from T1 fed cows was significantly higher (p<0.01). The results show that feeding TMR mixed for 30 minutes to dairy cows may improve the physical value of forage without negative effects on the milk yield and milk components. (Key words : Corn silage, Dairy cows, Laceration, Particle size, Total mixed rations)

The effect of nanoemulsified methionine and cysteine on the in vitro expression of casein in bovine mammary epithelial cells

Objective Dairy cattle nutrient requirement systems acknowledge amino acid (AAs) requirements in aggregate as metabolizable protein (MP) and assume fixed efficiencies of MP used for milk protein. Regulation of mammary protein synthesis may be associated with AA input and milk protein output. The aim of this study was to evaluate the effect of nanoemulsified methionine and cysteine on the in-vitro expression of milk protein (casein) in bovine mammary epithelial cells (MAC-T cells). Methods Methionine and cysteine were nonionized using Lipoid S 75 by high-speed homogenizer. The nanoemulsified AA particle size and polydispersity index were determined by dynamic light scattering correlation spectroscopy using a high-performance particle sizer instrument. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was performed to determine the cytotoxicity effect of AAs with and without nanoionization at various concentrations (100 to 500 μg/mL) in mammary epithelial cells. MAC-T cells were subjected to 100% of free AA and nanoemulsified AA concentration in Dulbecco’s modified Eagle medium/nutrient mixture F-12 (DMEM/F12) for the analysis of milk protein (casein) expression by the quantitative reverse transcription polymerase chain reaction method. Results The AA-treated cells showed that cell viability tended to decrease (80%) in proportion to the concentration before nanogenesis, but cell viability increased as much as 90% after nanogenesis. The analysis of the expression of genetic markers related to milk protein indicated that; αs2-casein increased 2-fold, κ-casein increased 5-fold, and the amount of unchanged β-casein expression was nearly doubled in the nanoemulsified methionine-treated group when compared with the free-nanoemulsified methionine-supplemented group. On the contrary, the non-emulsified cysteine-administered group showed higher expression of genetic markers related to milk protein αs2-casein, κ-casein, and β-casein, but all the genetic markers related to milk protein decreased significantly after nanoemulsification. Conclusion Detailed knowledge of factors, such nanogenesis of methionine, associated with increasing cysteine and decreasing production of genetic markers related to milk protein (casein) will help guide future recommendations to producers for maximizing milk yield with a high level of milk protein casein.

Effect of Types of Milking Instrument and Season on Milk Composition in Holstein-Friesian lactating Cows

ABSTRACT This study was conducted to examine the effect of different types of milking instrument and season on milk composition (fat, protein, non-fat milk solids, milk urea nitrogen and somatic cell count) on Holstein-Friesian lactating cows. Raw milk samples were collected from 20 automatic milking system (AMS) installed dairy farms and 85 conventional milking system (CMS) installed dairy farms. Milk fat, protein, NFMS and MUN contents did not changed between AMS and CMS and different seasons. On the other hand, the average SCC in AMS was 239×10 3 cells/mL which was lower than in CMS (373×10 3 cells/mL, (p<0.05). In conclusion, present results indicated that SCC in milk might be influenced by AMS. However, this area needed more study to confirm the reason of reducing SCC content from AMS. ( Key words : Automatic milking system, Conventional milking system, Season, Milk compositions) 서 론 1980년대 이후 젖소 사육농가 수는 지속적인 하락세를 보이고 있는 반면에 농가당 사육 두수는 1984년 9두에서 2013년 현재 71두로 지속적으로 증가해 왔다(Statistics Korea, 2013). 이는 국내 젖소농장도 타 축종과 유사하게 복합경영 농가 형태에서 전업농 또는 기업농 형태의 단일경영으로 빠르게 변화하고 있는 것으로 판단된다. 이에따라 목장의 착유시스템에도 많은 발전이 있었는데, 가구당 착유우 두수가 10두 미만인 1980년대에는 주로 손으로 착유를 하였으며 1980년대 중반 이후, 콤프레셔와 버킷식 설비가 목장에 도입되었으며, 냉각기 보조금 지급 및 보냉기능이 있는 집유차량이 목장별로 운행하기 시

Effects of Lactation Stage and Milk Yield on Reproductive Performance in Holstein Dairy Cows

【This study aimed to improve the reproductive efficiency of dairy herds by comparison and analyzing estrous appearance rate, conception and non-conception rate according to the stage of lactation using the lactation and reproductive records of average (less than 10,000 liters milk in 305 days) and high yielding (more than 10,000 liters milk in 305 days) Holstein cows (n=102). Milk production and reproduction data were collected between January 2010 and December 2012 from Holstein cows kept in the commercial dairy farms. Average (n=32) and high yielding (n=24) Holstein cows used to analyze the relationship between milk yield and reproductive performance. Our results showed that estrous appearance rate according to the stage of lactation was 25.0% (30~59d), 40.6% (60~89d), 25% (90~110d) and 9.4% (>111d) in average yielding cows and 16.7% (30~59d), 20.8% (60~89d), 12.5% (90~110d) and 50.0% (>111d) in high yielding cows, respectively. Conception rate according to the stage of lactation was 87.5% (30~59d), 61.5% (60~89d), 75.0% (90~110d) and 66.7% (>111d) in average yielding cows and 25.0% (30~59d), 0% (60~89d), 33.3% (90~110d) and 50.0% (>111d) in high yielding cows, respectively. Days between parturition and conception was 23.7% ( 210 d) in average yielding cows and 69.0% ( 210d) in high yielding cows, respectively. Conception rate from 110 days postpartum in high yielding cows was 41.7% (110~150d), 50.0% (151~180d) and 50.0% (>181d). Body condition score (BCS) in 120 days postpartum was

Effects of a Mixture of Eugenol, Thymol and Malate on Growth Performance, Beef Quality and Liver Function in Hanwoo Finishing Steers Fed a High-Concentrate Diet

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Effects of Ruminally Inserted Artificial Fiber on Growth Performance, Feed Intake and Carcass Characteristics of Hanwoo Steers

in average yielding cows and