Young-Han Song

Effects of Dietary Garlic Extract on Growth, Feed Utilization and Whole Body Composition of Juvenile Sterlet Sturgeon (Acipenser ruthenus)

This study was carried out to investigate the supplemental effects of dietary garlic extract (GE) on growth performance of juvenile sterlet sturgeon (Acipenser ruthenus). The first experiment was designed to determine the optimum levels of garlic extract as growth promoter during 10 weeks. Three groups (two replicates/group) of 240 fish with mean body weight of 85 g were fed with diets containing 0 (control), 0.5 and 1.0% of GE. The highest weight gain (%) and feed efficiency (%) were found in fish groups fed with diet containing 0.5% GE. Subsequently, the supplemental effects of dietary GE was studied on growth of juvenile sterlet sturgeon (Acipenser ruthenus) with an average body weight of 59.6 g. Fish cultured in freshwater were randomly allotted to each of 10 tanks (two groups of five replicates, 20 fish/tank) and fed diets with 0.5% GE or without GE (control), respectively, at the level of 2.0% of fish body weight per day for 5 weeks. Weight gain (51.1%), feed efficiency (79.1%), specific growth rate (1.18%) and protein efficiency ratio (1.50) of fish fed 0.5% GE were significantly (p<0.05) higher than those fish fed the control diet. Significantly higher protein (PRE 20.4%) and lipid retention efficiencies (LRE, 74.5%) were also found in 0.5% GE group (p<0.05). The present results suggested that dietary GE could improve growth and feed utilization of juvenile sterlet sturgeons.

Association of a single nucleotide polymorphism in the akirin 2 gene with economically important traits in Korean native cattle

The akirin 2 gene, located on chromosome 9 in cattle, was previously reported to be associated with nuclear factor-kappa B (NF-κB), involved in immune reactions and marbling of meat. To determine whether a single nucleotide polymorphism (SNP) in akirin 2 is associated with economically important traits of Korean native cattle, the c.*188G>A SNP DNA marker in the 3-UTR region of akirin 2 was analyzed for its association with carcass weight, longissimus muscle area and marbling. The c.*188G>A SNP was genotyped by polymerase chain reaction restriction fragment length polymorphism, and the frequency of the AA, AG, and GG genotypes were 6.82%, 71.29% and 21.88% respectively. This SNP was significantly associated with longissimus muscle area (Bonferroni corrected Pxa0<xa00.05), and marbling score (Bonferroni corrected Pxa0<xa00.01). These results suggest that the c.*188G>A SNP of akirin 2 might be useful as a DNA marker for longissimus muscle area and marbling scores in Korean native cattle.

Prediction of Carcass Meat Quality Grade by Ultrasound in Hanwoo

For the establishment of prediction strategies of carcass meat quality grade and for the enhancement of prediction accuracy, sixty six Hanwoo steers were ultrasonically tested at 24 months of age. Ultrasonic meat quality grade were predicted by standard ultrasonic image and decision tree method using ultrasonic meat quality index. From the results of decision tree method using ultrasonic meat quality index, it was found that the marbling score was mainly influenced by the distinctness of rib on ultrasound image. Prediction accuracy of meat quality grade by ultrasonic meat quality index was 86.4%, resulting in 7.6% higher accuracy than that by standard ultrasonic image (78.8%).

Early Prediction of Carcass Yield Grade by Ultrasound in Hanwoo

This study was carried out to make early prediction of carcass yield grade. Sixty six Hanwoo steers were measured for back fat thickness, longissimus muscle area and body weight at 18, 21 and 24 months of age by ultrasound. Carcass evaluation was done after ultrasound measurement at 24 month of age. Ultrasonic yield grade at 18, 21 and 24 month of age were predicted by regression and decision tree methods. Classifying by carcass yield grade, ultrasonic back fat thickness at 18, 21 and 24 months of age was significantly different in each carcass yield grade (p

Effects of Raising Farm on Genetic Evaluation for Carcass Traits in Hanwoo Cows

This research was conducted to analyze the effects of raising farm on the heritability and breeding values of Hanwoo cows for their carcass traits, including cold carcass weight (CWT), back-fat thickness (BFT), eye-muscle area (EMA) and marbling score (MAR). The carcass data and pedigree data were collected from steers raised on Hanwoo farms in Pyeongchang-gun, Gangwon-do, South Korea. Three analytical models were applied for the estimation of heritabilities and breeding values. The first model (model 1) included slaughter house-year-month combination as fixed effects and age at slaughter was fitted as linear and quadratic covariates. The second model (model 2) was similar to model 1, but raising farm was additionally included as random effect. The third model (model 3) was similar to model 1 but farm effects were additionally included as fixed effect. The comparisons between the model 1 and the models including farm effect (model 2 and model 3) revealed that heritability estimates from model 2 or model 3 were smaller to those from model 1 for all carcass traits. Especially, obvious decrease of heritability was observed in CWT where heritability was 0.23 from model 1, 0.15 from model 2 and 0.18 from model 3. The maximum log likelihood of the model 2 and 3 were higher than those of model 1 for all traits. In model 2 that raising farm was included as a random effect, the ratio of farm variance to the total phenotypic variance were ranged from 4% (EMA) to 18% (CWT). Top 10% and bottom 10% of female cows were selected based on the breeding values from model 1, and the Spearmans rank correlation coefficients among models were estimated for each trait within selected group. The correlation coefficients were ranged from 0.57 to 0.95 in top 10% group and from 0.68 to 0.95 in bottom 10% group. These results show that the discrepancies in the rankings of breeding values can be based on the models applied. In conclusion, the results obtained in this study suggest that the herd effect or farm effect should be included in the analytical model when breeding values are estimated with the purpose of improvement of carcass traits of Hanwoo breeding cows. (Key words : Hanwoo, Carcass trait, Farm effect, Heritability)

Analysis of Factors for Seasonal Meat Color Characteristics in Hanwoo(Korean Cattle) Beef using Decision Tree Method

This study analyzed the effects of pH, sex, backfat thickness, ribeye area, cold carcass weight, shipping month, muscle internal temperature, average daily temperature, and average relative humidity for slaughtered Hanwoo to meat color by season. The analyses focused on interaction and each effect to meat color of the factors. For the result for analysis of multiple linear regressions, meat color values were decreased as pH increased in all meat color, and the meat color values increased as the backfat thickness was increased. As the results of the decision tree analysis by each factor, cow and steer slaughtered in spring and autumn were the highest in the lightness(L*). The redness(a*) was the cases that pH was less than 5.63 and average relative humidity was over than 71.5% for Hanwoo slaughtered in autumn. The chroma(C*) value was the highest for Hanwoo that was slaughtered in summer and autumn, the pH was less than 5.60, and the back fat thickness was over than 8 mm. The hue angle() was shown that the muscle internal temperature was less than 4.7 among Hanwoo which was slaughtered in spring, summer, and autumn, the pH was less than 5.66, and the back fat thickness was over than 8 mm.

Evaluation on the Greenhouse Gas Emission According to the Intake Levels of Total Mixed Rations of Hanwoo Cow

This study was conducted to investigate the effects of different feeding level of TDN (Total Digestible Nutrients) on the generation of main greenhouse gases such as carbon dioxide and methane in Hanwoo cows. The diet TDN (kg) adjusted to achieve ADG of 0 g/day (Control), 200 g/day (T1), and 400 g/day (T2) of the maintenance level TMR (Total Mixed Ration) delivered twice a day at 08:30 and 17:30. Cow are housed in a respiration chamber and the environmental temperature was maintained at 20 . The gases were measured for 24 hours using the multi-detector instrument Mamos-300. The analyzed methane emissions of T1 and T2 were 33.5% and 69.6% higher than control, respectively, and the carbon dioxide emissions were 21.1% and 40.6% higher than control. Also, the hourly pattern of carbon dioxide and methane production were showed very similar emission. Gas production showed peak after 1 hour of feeding and this gap was wider in the afternoon than in the morning hours. It is clearly conducted that CO2 and CH4 emissions were different by limited intake levels of feed. (Key words : Carbon dioxide, Hanwoo, Methane gas, TDN, TMR)

Prediction of Carcass Yield by Ultrasound in Hanwoo

This study was conducted to predict the carcass yield traits using ultrasound before slaughter and to enhance the prediction accuracy of carcass yield grade by applying various strategies. For this experiment, five hundred seventy three Hanwoo steers of 24 months of age were used. Difference between ultrasound result and carcass measure of BFT and LMA was 0.61.65mm and 0.75.56cm2, respectively. Correlation coefficient between ultrasound result and carcass measure of BFT and LMA was 0.86 and 0.82, respectively (p

Studies on the Failure Rate of Artificial Insemination in Korean Native Cows

본 연구는 강원도 영동지방에서 사육중인 1,619두의 암소를 대상으로 암소의 인공수정 실패율에 관한 조사 연구를 실시하였다. 분석에 이용된 1,619두 암소의 평균 인공수정 실패율은 34.36%로 나타났고, 동해시에서 41.46%로 가장 높은 인공수정 실패율을 보여 각 지역별로 인공수정 실패율에 차이가 있는 것으로 나타났다. 산차에 따른 인공수정 실패율에 따르면 1 산차에서 가장 높은 실패율인 49.14%를 나타냈으며, 5 산차에서 가장 낮은 실패비율인 29.91%를 나타내 산차가 증가함에 따라 인공수정 실패율이 낮아지는 경향을 나타냈으나, 6 산차 이상의 경우 실패율이 높아지는 것으로 나타났다. 또한, 둔근지방 두께(rump fat thickness by ultrasound)에 따른 암소의 인공수정 실패율을 비교하였을 때 둔근지방 두께가 15 mm 초과인 경우 인공수정 실패비율이 33.4%로 가장 높게 나타났으며, 5 mm 초과 10 mm 이하에서 가장 낮은 비율(28.9%)을 보여 둔근지방의 두께와 인공수정 실패 사이에는 밀접한 연관이 있는 것으로 사료된다. 인공수정 실패율이 높은 어미암소가 생산한 자우암소의 인공수정 실패율이 높을 확률은 약 80% 이상으로 나왔으며, 어미암소와 자우암소의 인공수정 실패율은 0.2186의 정의 상관관계를 나타내었다. 이상의 결과를 종합하여 볼 때 암소의 인공수정에 영향을 미치는 요인은 암소의 둔근지방 두께, 산차, 어미암소의 수태율 등으로 분류할 수 있었으며, 한우 번식능력을 평가할 수 있는 기초 자료로써 이용할 수 있을 것으로 사료된다. 더 나아가 강원 영동지방이 아닌 전국에 더 많은 샘플 수집을 통해 분석해야 할 것이며, 번식형질에 관련된 유전자 탐색 및 단일염기다형성분석 또한 이루어져야 할 것으로 사료된다. 【This study was carried out to investigate the influence of artificial insemination (AI) failure in 1,619 Korean native cows at Gangwon East area, Korea. The average AI failure rate was 37.02% in the cows and the highest rate was 40.85% in Yangyang-city. Based on the parity in the cows, the AI failure rate was 49.14% and 29.91% in the first and fifth parity cows, respectively. Whereas cows until fifth parity were decreased in AI failure, cows with sixth or more parity showed an upturning AI failure trends with the increasing of parity number. AI failure rate incidence according to the rump fat thickness measured by ultrasound was 28.9% and 33.4% at 5 mm to 10 mm and over than 15 mm, respectively. There was a positive correlation (0.2186) between AI failure rate of mother and that of their offspring cows. That is, offspring of dams with high AI failure rate showed also higher AI failure than those of dams having lower AI failure rate. In conclusion, these results indicate that the AI failure rate was closely related to the rump fat thickness, parity number, and conception rate of mother cows. In addition, these results might strengthen the basis to improve the reproductive performance in Korean native cows.】