Byoungho Park

Development of International Genetic Evaluation Models for Dairy Cattle

This study was aimed to solve the problems of current national genetic evaluation systems in Korea and its development to pass the verification processes as required by International Bull Evaluation Service (Interbull). This will enable Korea to participate in international genetic evaluation program. A total of 1,416,589 test-day milk records with calving dates used in this study were collected by National Agricultural Cooperative Federation from 2001 to 2009. Parity was limited up to fifth calving and milk production records were adjusted to cumulative 305 day lactation. The pedigree consisted of 2,279,741 animals where 2,467 bulls had 535,409 parents. A newly developed multiple trait model was used in calculation of breeding values for milk yield, milk fat, and protein yield. Data were edited with SAS (version 9.2) and R programs, and genetic parameters were estimated using VCE 6.0. Results showed a continuous increase in genetic potentials, in general, and no remarkable differences were found between performances by parity. Except fat yield, potentials in milk yield and protein yield were well calculated. We found an increased number of daughters per each top ranked 1,000 bulls in recent years of calf births compared to the cases of previous evaluations. Of the bulls ranked top 100 by our new models (multiple-trait models) we found that increased numbers of bulls were included. Of twenty eight bulls born in 2006, twenty bulls born in 2007 and eight bulls born in 2008 that were listed by new models, only 23, 12, and 2 bulls born in respective years were represented on top 100 by old single-trait models. Re-ranking of the daughters or sires by multiple-trait models suggest that this new multiple trait approach should be used for dairy cattle genetic evaluation and seed-stock selection in the future to increase the accuracy of multiple trait selection. Breeding values for these traits should also be calculated by new method for international genetic evaluation. (Key words : Holestein, Genetic evaluation, Multiple trait models, Breeding values)

Comparison of Hanwoo Proven and Young Bulls for Major Economic Traits

2004년부터 2006년까지 상 하반기에 후대검정에 공시한 후보씨수소와 동일 시점에 판매한 보증씨수소의 표현형 및 유전 능력을 비교하였다. 12개월령 체중, 도체중 및 등심단면적의 표현형 능력의 경우 대부분 후보씨수소가 유의하게 우수하였으며, 등지방두께 표현형 능력의 경우 후보씨수소가 유의하게 두꺼웠다. 12개월령 체중, 도체중, 등심단면적, 등지방두께 및 근내지방도의 유전능력과 선발지수를 비교한 결과 후보씨수소와 보증씨수소 사이에 대부분 유의한 차이가 없었다. 후보씨수소와 1등급 보증씨수소의 유전능력을 비교한 결과 등심단면적을 제외하고는 유의한 차이가 없었다. 【This study was conducted to compare the phenotypic performance and genetic merits in terms of weight at 12 months, carcass weight, eye muscle area, backfat thickness, marbling score and selection index of Hanwoo young bulls and proven bulls from the year 2004 to 2006. The data of 208 bulls used in this study were taken from the Nnational Hanwoo genetic evaluation coordinated by National Institute of Animal Science. Hanwoo young bulls were superior in the phenotypic performance of weight at 12 months, carcass weight, and eye muscle area showing significant differences from Hanwoo proven bulls in most comparisons. The backfat thickness of Hanwoo young bulls was significantly thicker higher than Hanwoo proven bulls in all comparisons (p】

Physicochemical, Microbiological and Sensory Properties of Korean Frozen Pork Loins for Export

The Korean frozen pork loins in vacuum packaged were obtained from three different Korean export companies and investigated for pH, proximate composition, cooking loss, physico-chemical and sensory characteristics. The frozen pork loins were stored at -20 for 40 days. The results were as follows: The protein contents were relatively higher in the samples from the company II and the ash contents were relatively higher in the samples from the company I than those from the other companies. The samples from the company Ⅱ had highest pH and water-holding capacity, and cooking loss and shear force were lowest in the company II. The total plate counts and coliform bacteria for loins from 3 companies were in the range of 3.043.75 log cfu/ or g and 0.371.32 log cfu/ or g in average, respectively. The TBARS values were 0.350.38 mg malonaldehyde/kg sample. There were no significant differences in sensory characteristics for raw and cooked loins from all companies.

Estimation of Genetic Parameters for Milk Production Traits in Holstein Dairy Cattle

The purpose of this study was to estimate (co) variance components of three milk production traits for genetic evaluation using a multiple lactation model. Each of the first five lactations was treated as different traits. For the parameter estimation study, a data set was set up including lactations from cows calved from 2001 to 2009. The total number of raw lactation records in first to fifth parities reached 1,416,589. At least 10 cows were required for each contemporary group, herd-year-season effect. Sires with fewer than 10 daughters were discarded. Lactations with 305d milk yield exceeding 15,000 kg were removed. In total, 1,456 sires of cows were remained after all the selection steps. A complete pedigree consisting of 292,382 records was used for the study. A sire model containing herd-year-season, caving age, and sire additive genetic effects was applied to the selected lactation data and pedigree for estimating (co) variance components via VCE. Heritabilities and genetic or residual correlations were then derived from the (co) variance estimates using R package. Genetic correlations between lactations ranged from 0.76 to 0.98 for milk yield, 0.79~1.00 for fat yield, 0.75~1.00 for protein yield. On individual lactation basis, relatively low heritability values were obtained 0.14~0.23, 0.13~0.20 and 0.14~0.19 for milk, fat, and protein yields, respectively. For the combined lactation heritability values were 0.29, 0.28, and 0.26 for milk, fat, and protein yields. The estimated parameters will be used in national genetic evaluations for production traits. (Key words : Holestein, Genetic parameters, Milk production traits, Heritability )

Comparison of Proven and Young Holstein Bulls for Major Economic Traits

You Lim Choi*, Kwang Hyun Cho*, Byeong Soon Jeon*, Kwang Soo Baek*, Byoungho Park*, Hyun Joo Lim*,Hyo Sun Kim*, Joo Hyun Cho**, Byeong Seog Ahn* and Nae Soo Kim***National Institute of Animal Science, RDA*, Dairy Cattle Improvement Center, NACF**,Chungbuk National University***ABSTRACTThe Objective of this study was to compare performances of proven and young holstein bulls bred in Korea. Proven bulls are categorized into the imported and the korean ones. Data from 148,329 heads of daughters of 1,128 bulls from 1990 to 2004 were used in this study. Proven bulls showed higher milk yield than young bulls in same year. Young bulls, however, always yielded more milk than korean bulls when proven bulls were categorized into the imported and the korean ones. Hence, it was proven that dairy bull selection program had properly been functioned in Korea. Selected bulls, which were korean proven bulls and young bulls, yielded higher milk fat than imported bulls as the selection was weighted on the yield of the milk fat. This comparison was based on the performances of daughters without the consideration of the semen price. Semen price of the imported proven bulls were higher than the korean proven bulls and the semen of young bulls was free. Hence, the performances of korean bulls with the consideration of the preferential effect would be much higher than others, and further studies are necessary.(Key words :Holstein, Proven bull, Young bull, Progeny test)

Microbiological and Sensory Characteristics of Vacuum Packed Korean Chilled Pork Loins for Export

The Korean fresh pork loins in vacuum packaged were obtained from three different Korean export companies and investigated for microbiological and sensory properties. The fresh pork loins were stored at 2 for 50 days and analyzed with an interval of 510 days. The results were as follows: The overall numbers of total plate counts and coliform bacteria were higher in swab method than in meat sampling method. The total plate counts in the loins from the company I were maintained low levels (10 cfu/ or 10 cfu/g) for entire storage periods(50 days at 2), whereas the loins from the company III had high levels when they were compared to the domestic standard for the allowance limit. The samples from the company III showed that total plate counts were over 106 after about 30 days when determined by meat sampling method and total plate counts were over 106 after 15 days when determined by swab method. The overall numbers of coliform bacteria were also significantly lowest in the samples from the company I, whereas they were highest in the company III. Therefore, all meat companies will have to make an effort to prevent bacterial contamination in each stage such as slaughtering, marketing and consumer in order to ensure the production of safe meat and the extension of shelf-life. For fresh products, scores of intramuscular fat were higher in samples form the companies II and III than those from the company I when visibly evaluated with the standard. There were no significant differences in scores of meat color, drip and fresh meat flavor. However, the samples from the company I had the lowest score of off-flavor and highest score of overall acceptability. For cooked products, there were no significant differences in meat flavor, off-flavor, juiciness and overall acceptability.

Correlation Analyses on Body Size Traits, Carcass Traits and Primal Cuts in Hanwoo Steers

This study was conducted to estimate the correlation structure between body size traits, carcass traits, and primal cuts in Hanwoo steers. Hanwoo progeny test data (body weight and body measurements) were collected from 2008 to 2010 from a total of 882 steers at the Hanwoo Improvement Main Center (NACF). Carcass traits considered were cold carcass weight, eye muscle area, backfat thickness, and marbling scores evaluated at the time of carcass grading. Correlation analyses were performed with observed scales of the traits and with residuals considering fixed environmental effects in generalized linear models. The correlation coefficient estimated between loin weight and chest girth was high at 0.74. The shank negatively correlated with pelvic width (-0.23) and hipbone width (-0.27). In addition, rib weight and chest girth was highly correlated (0.80). The correlation between carcass weight and chest girth was 0.86 in observed scale. Residual correlation between these traits was estimated at 0.65. Correlation between carcass weight and loin was 0.87 in the observed scale. Residual correlation was estimated at 0.83. The correlation coefficient estimated between shank weight and brisket and flank weight was negative at -0.69. Chest girth had a high correlation between primal cuts weight and body measurements. Thus, we believe that these results will provide a greater understanding on the relationship of primal cuts and other phenotypes, thus enabling valid production models for Hanwoo steers.

Development of Algorithm in Analysis of Single Trait Animal Model for Genetic Evaluation of Hanwoo

Estimate breeding value can be used as single trait animal model was developed directly using the Fortran language program. The program is based on data computed by using the indirect method repeatedly. The program develops a common algorithm and imprves efficiency. Algorithm efficiency was compared between the two programs. Estimated using the solution is easy to farm and brand the service, pedigree data base was associated with the development of an improved system. The existing program that uses the single trait animal model and the comparative analysis of efficiency is weak because the estimation of the solution and the conventional algorithm programmed through regular formulation involve many repetition; therefore, the newly developed algorithm was conducted to improve speed by reducing the repetition. Single trait animal model was used to analyze Gauss-Seidel iteration method, and the aforesaid two algorithms were compared thorough the mixed model equation which is used the most commonly in estimating the current breeding value by applying the procedures such as the preparation of information necessary for modelling, removal of duplicative data, verifying the parent information of based population in the pedigree data, and assigning sequential numbers, etc. The existing conventional algorithm is the method for reading and recording the data by utilizing the successive repetitive sentences, while new algorithm is the method for directly generating the left hand side for estimation based on effect. Two programs were developed to ensure the accurate evaluation. BLUPF90 and MTDFREML were compared using the estimated solution. In relation to the pearson and spearman correlation, the estimated breeding value correlation coefficients were highest among all traits over 99.5%. Depending on the breeding value of the high correlation in Model I and Model II, accurate evaluation can be found. The number of iteration to convergence was 2,568 in Model I and 1,038 in Model II. The speed of solving was 256.008 seconds in Model I and 235.729 seconds in Model II. Model II had a speed of approximately 10% more than Model I. Therefore, it is considered to be much more effective to analyze large data through the improved algorithm than the existing method. If the corresponding program is systemized and utilized for the consulting of farm and industrial services, it would make contribution to the early selection of individual, shorten the generation, and cultivation of superior groups, and help develop the Hanwoo industry further through the improvement of breeding value based enhancement, ultimately paving the way for the country to evolve into an advanced livestock country.

Estimation of Primal Cuts Yields by Using Body Size Traits in Hanwoo Steer

ABSTRACT The study aimed to develop prediction models of primal cut yield using body measurements of Hanwoo steers in Korea. The progeny of 874 steers at Hanwoo Improvement Main Center from 2008 to 2010 were recorded. Pearson’s correlation coefficients for primal cuts and other traits were estimated. Primal cuts were adjusted for slaughter date and age using the SAS GLM procedure. Afterwards, a stepwise regression was performed on each primal cut by fitting body measurement traits. An independent covariable was selected at the highest coefficient of determination with the greater fitness model using Mallows’s Cp statistic. Results showed that primal cuts were significantly influenced by slaughter date (P<0.01). The age at slaughter, however, was only significant for the top round (P<0.05). There was a moderate to high correlation between chest girth and tenderloin (0.54), loin (0.74), and rib (0.80). Most primal cut percentages were negatively related to BFT. Similar negative to low positive correlations were observed for primal cut percentage and body size traits. In addition, a correlation of 0.21 was observed between rib percentage and chest girth. The regression of body measurements on the adjusted primal cuts were significant for later traits. Regression estimates revealed that wither height, body length, rump length, hip bone width, and chest girth are important for primal cut weight and percentage determination. In particular, chest girth was always important for primal cut weight estimates. (

Evaluation of the Degrees of Genetic Connectedness Among Duroc Breed Herds

The genetic connectedness between herds is an essential requirement to make robust across-herd estimation of the breeding values of the animals. In this study, genetic connectedness between herds was evaluated by a connectedness rating method. A total of 24,971 records of days to 90 kg (D90KG) of the pigs on performance testing programs collected from six herds (labeled from A to F) of Duroc breed along with pedigree information comprising 456,697 families were used. Results showed that a total of eight boars were used for semen exchange programs among participant farms. Herds A through E were found strongly connected among them. But F herd was genetically connected strongly only with A herd. The highest average connectedness rating was 91.7% between A herd and C herd. The lowest average connectedness rating was 65.1% between D and F. The concept of a single genetic group comprising six Duroc herds studied is meaningful due to high connectedness rates among them. Therefore, with this high genetic ties between participant Duroc farms, the more accurate genetic evaluation would be possible.