• 농업과학연구
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• 제50권4호
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• pp.869-881
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• 2023

A genetic improvement program in Korea was implemented to improve the performance of Hanwoo cattle by generating livestock with genetically desirable economic characteristics. In particular, in response to external changes, such as the expansion of Free Trade Agreement (FTA), the livestock genetic improvement program has increased farm income by improving the productivity and quality of Hanwoo cattle. Using production cost data from Statistics Korea, the total input and output indices of Hanwoo feeding cattle from 2008 - 2021 were estimated and the growth and productivity changes were analyzed. The productivity change measures results were used to estimate the cumulative effects of the Hanwoo genetic improvement program on quality improvement, another purpose of the program, using a finite distributed lag model. The average annual increase in output (market weight) of Hanwoo was 0.9%. However, total input increased by 1.6%, resulting in a 0.6% decline in total factor productivity. In contrast, the Hanwoo genetic improvement program contributed significantly to the production of high quality beef, rather than contributing to improved productivity of the cattle. Hanwoo carcass weight, which is used as a performance indicator for the livestock genetic improvement program, has significantly improved and is projected to increase at a slower rate. The collective findings indicate the need for new performance indicators that can comprehensively indicate the performance of the genetic improvement of Hanwoo.

• Asian-Australasian Journal of Animal Sciences
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• 제12권8호
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• pp.1316-1323
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• 1999

Extensive emphasis on milk and milk fat yields with no diversion for beef performance increased the yield efficiency of North American dairy cattle. Heavy demand for North American genetics followed national strain comparison trials in Poland, and US and Canadian dairy cattle and germplasm still are an important source of genetics for many countries. Genetic improvement has accelerated in many countries because of the implementation of sampling programs for young bulls and improved evaluation procedures. Rapid access to information and more frequent calculation of genetic information also are having a positive impact on genetic improvement. Traits other than yield should be considered in a breeding program, but those traits mist have a reasonable opportunity for improvement and sufficient economic worth. Because of ever increasing efficiency, the world's milk supply comes from fewer cows each year. However, no decline in the rate of genetic improvement is apparent under current genetic practices; estimates of heritability are increasing, and a decline in yield efficiency is unlikely in the near future. As management improves, especially for subtropical conditions, many of the selection principles used in temperate climates will be adopted for more adverse environmental conditions.

• Asian-Australasian Journal of Animal Sciences
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• 제33권9호
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• pp.1369-1377
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• 2020

Objective: The main objectives of the present study were to assess the genetic diversity, population structure and to appraise the efficiency of ongoing selective breeding program in the closed nucleus herd of Nellore sheep through pedigree analysis. Methods: Information utilized in the study was collected from the pedigree records of Livestock Research Station, Palamaner during the period from 1989 to 2016. Genealogical parameters like generation interval, pedigree completeness, inbreeding level, average relatedness among the animals and genetic conservation index were estimated based on gene origin probabilities. Lambs born during 2012 and 2016 were considered as reference population. Two animal models either with the use of F_i or ΔF_i as linear co-variables were evaluated to know the effects of inbreeding on the growth traits of Nellore sheep. Results: Average generation interval and realized effective population size for the reference cohort were estimated as 3.38±0.10 and 91.56±1.58, respectively and the average inbreeding coefficient for reference population was 3.32%. Similarly, the effective number of founders, ancestors and founder genome equivalent of the reference population were observed as 47, 37, and 22.48, respectively. Fifty per cent of the genetic variability was explained by 14 influential ancestors in the reference cohort. The ratio f_e/f_a obtained in the study was 1.21, which is an indicator of bottlenecks in the population. The number of equivalent generations obtained in the study was 4.23 and this estimate suggested the fair depth of the pedigree. Conclusion: Study suggested that the population had decent levels of genetic diversity and a non-significant influence of inbreeding coefficient on growth traits of Nellore lambs. However, small portion of genetic diversity was lost due to a disproportionate contribution of founders and bottlenecks. Hence, breeding strategies which improve the genetic gain, widens the selection process and with optimum levels of inbreeding are recommended for the herd.

• Journal of Animal Science and Technology
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• 제55권1호
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• pp.1-6
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• 2013

본 연구는 국내 국가단위 평가결과의 문제점을 해결하면서 유전 능력평가시스템을 고도화하고 우리나라가 국제유전평가에 참여하기 위하여 국제평가기구에서 요구하는 검증작업을 통과하기 위하여 수행하였다. 본 연구에 이용된 자료는 농협중앙회 젖소개량부에서 수집한 분만일이 2001년부터 2009년까지의 검정성적으로 총 1,416,589개이며 산차는 5산으로 제한하였으며, 누적착유일은 75~305일로 제한하였고, 전체 혈통자료는 2,279,741개이며 부모를 갖는 개체는 535,409개이고 아비소는 2,467두로 구성되어 있는 기록들을 이용하였다. 유량, 유지방, 유단백에 대한 육종가는 신규로 개발한 다형질모형(Multiple traits model)을 이용하여 육종가를 구하였으며 기초작업은 SAS version 9.2와 R프로그램을 이용하였으며 유전모수를 추정하기 위하여 VCE 6.0을 이용하였다. 전반적으로 유전적 추세는 꾸준히 지속되어 오고 있으며 산차별 차이가 두드러지게 나타나지는 않았다. 유지방을 제외하고 유량과 유단백 형질의 추세가 잘 추정되었음을 알 수 있다. 유전평가분석결과 상위 1000두의 랭킹안에 최근의 생년을 갖는 딸소가 기존에 사용한 모수로 분석한 결과보다 딸소가 증가했음을 알 수 있다. 국제유전평가모형을 통해 새로 평가한 결과 씨수소상위 100두를 기존 평가모형에 의한 평가결과와 비교했을 때, 2006년생은 23두에서 28두로 2007년생은 12두에서 20두로 2008년생은 2두에서 8두로 증가하였다. 이는 최근의 딸소나 씨수소의 유전능력이 우수함에도 불구하고 상위에 랭크되지 못했던 결과가 새 모형의 적용으로 보완하여 새로운 평가분석에 적용할 수 있을 것으로 판단된다. 따라서 기존의 단형질 모형 대신 다형질 모형을 이용한 분석방법으로 평가를 실시하고 국제유전평가에도 다형질 모형을 이용한 육종가를 제시함으로써 다형질 선발의 정확도가 향상될 수 있을 것이다.

• Asian-Australasian Journal of Animal Sciences
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• 제5권4호
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• pp.623-628
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• 1992

Records on weaning (3803) and yearling weight (2990) of beef cattle (Bibos banteng) from the Bali Cattle Improvement Project were examined. A mixed model analysis involving all main non-genetic effects (village, year of birth, season of birth, age of dam, sex of calf, all significant interactions and age at weighing as a covariate) as fixed effects and sire nested within village as a random effect was undertaken. Variance components were estimated by Henderson's Method III. Paternal half-sib components of variance and covariance were used to estimate heritabilities of weaning and yearling weights, as well as their genetic and phenotypic correlations. Heritability estimates ($\pm$ standard error) obtained by Henderson's Method III for weaning and yearling weights were $.11{\pm}.03$ and $.13{\pm}.04$, respectively while the phenotypic and genetic correlations were estimated as .32 and $.64{\pm}.10$, respectively. The parameters estimated in this study were at the lower end of the range of reported values from various breeds. It is concluded that further information should be gathered to assist in estimating genetic parameters for other economic traits of Bali beef cattle and to provide more accurate estimates for weaning and yearling weights. These parameters should then be used to formulate a selection program to enable the genetic improvement of Bali Beef cattle.

• 한국수정란이식학회지
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• 제28권2호
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• pp.79-85
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• 2013

The recent development in genetic assisted selection (combining traditional- and genome assisted selection method) and reproduction technologies will allow multiplying elite cow in Hanwoo small farm. This review describes the new context and corresponding needs for genome assisted selection schemes and how reproductive technologies can be incorporated to get more genetic gain for cow genetic improvement in Hanwoo. New improved massive phenotypes and pedigree information are being generated from commercial farm sector and these are allowing to do genetic evaluation using BLUP to get elite cows in Korea. Moreover cattle genome information can now be incorporated into breeding program. In this context, this review will discuss about combining the reproductive techniques (Multiple Ovulation Embryo Transfer; MOET) and genome assisted selection method to get more genetic gain in Hanwoo breeding program. Finally, how these technologies can be used for multiplication of elite cow in small farm was discussed.

• Journal of Animal Science and Technology
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• 제48권6호
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• pp.759-766
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• 2006

본 연구는 농협중앙회 가축개량사업소가 보유하고 있는 1998년부터 2005년까지 실시한 한우 당대검정 대상우 2,532두의 자료와 1996년부터 2002년까지 실시한 한우 후대검정 대상우 1,819두의 자료를 이용하여 당대 및 후대의 형질을 다형질 개체모형을 이용하여 유전모수를 추정하였다. 적합한 통계분석모형을 찾기 위하여 각 형질별로 회귀분석을 통한 변수선택방법으로 고정효과와 공변량을 결정하고, MTDFREML 패키지를 이용하여 유전모수를 추정하였다. 분석형질은 등지방두께, 도체중, 도체율, 등심단면적, 근내지방도 및 12개월령 체중으로, 이들의 유전력은 각각 0.51, 0.32, 0.27, 0.33, 0.50 및 0.26로 나타났다. 한편 유전평가에서 제외되었던 등지방두께 및 도체율의 유전력이 각각 0.51 및 0.27으로 추정되어 이에 대한 선발이 가능할 것으로 나타났다. 특히 등지방두께는 현 육량지수 산출식에서 그 영향력이 매우 크므로 한우보증씨수소 선발지수에 포함하는 방안을 고려할 필요가 있을 것으로 사료된다. 도체형질간의 유전상관은 등지방두께와 등심단면적을 제외하고 모두 양의 상관을 나타났다. 그러나, 12개월령 보정체중과 도체율 및 근내지방도의 유전상관은 각각 0.09 및 0.27으로 나타나 현행 한우개량체계에서 처럼 당대검정우를 12개월령 체중으로 선발할 경우 등심단면적과 근내지방도가 우수한 개체가 탈락할 가능성이 있는 것으로 나타나 이의 보완을 위한 혈통지수의 활용방안이나 초음파단층촬영기술의 이용방법에 대한 추가연구가 필요한 것으로 사료된다.

• Asian-Australasian Journal of Animal Sciences
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• 제26권4호
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• pp.470-475
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• 2013

The objective of this study was to estimate genetic parameters that are to be used for across-herd genetic evaluations of seed stock pigs at GGP level. Performance data with pedigree information collected from swine breeder farms in Korea were provided by Korea Animal Improvement Association (AIAK). Performance data were composed of final body weights at test days and ultrasound measures of back fat thickness (BF), rib eye area (EMA) and retail cut percentage (RCP). Breeds of swine tested were Landrace, Yorkshire and Duroc. Days to 90 kg body weight (DAYS90) were estimated with linear function of age and ADG calculated from body weights at test days. Ultrasound measures were taken with A-mode ultrasound scanners by trained technicians. Number of performance records after censoring outliers and keeping records pigs only born from year 2000 were of 78,068 Duroc pigs, 101,821 Landrace pigs and 281,421 Yorkshire pigs. Models included contemporary groups defined by the same herd and the same seasons of births of the same year, which was regarded as fixed along with the effect of sex for all traits and body weight at test day as a linear covariate for ultrasound measures. REML estimation was processed with REMLF90 program. Heritability estimates were 0.40, 0.32, 0.21 0.39 for DAYS90, ADG, BF, EMA, RCP, respectively for Duroc population. Respective heritability estimates for Landrace population were 0.43, 0.41, 0.22, and 0.43 and for Yorkshire population were 0.36, 0.38, 0.22, and 0.42. Genetic correlation coefficients of DAYS90 with BF, EMA, or RCP were estimated to be 0.00 to 0.09, -0.15 to -0.25, 0.22 to 0.28, respectively for three breeds populations. Genetic correlation coefficients estimated between BF and EMA was -0.33 to -0.39. Genetic correlation coefficient estimated between BF and RCP was high and negative (-0.78 to -0.85) but the environmental correlation coefficients between these two traits was medium and negative (near -0.35), which describes a highly correlated genetic response to selection on one or the other of these traits. Genetic Trends of all three breeds tend to be towards bigger EMA or greater RCP and shorter DAYS90 especially from generations born after year 2000.

• Asian-Australasian Journal of Animal Sciences
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• 제4권4호
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• pp.305-328
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• 1991

Pig breeding programs have been very successful in the improvement of animals by the simple expedient of focusing on a few traits of economic importance, particularly growth efficiency and leanness. Further reductions in leanness may become more difficult to achieve, due to reduced genetic variation, and less desirable, due to adverse correlated effects on meat and eating quality. Best linear unbiased prediction (BLUP) of breeding values makes possible the incorporation of data from many sources and increases the value of including traits such as sow performance in the breeding objective. Advances in technology, such as electronic animal identification, electronic feeders, improved ultrasonic scanners and automated data capture at slaughter houses, increase the number of sources of information that can be included in breeding value predictions. Breeding program structures will evolve to reflect these changes and a common structure is likely to be several or many breeding farms genetically linked by A.i., with data collected on a number of traits from many sources and integrated into a single breeding value prediction using BLUP. Future developments will include the production of a porcine gene map which may make it possible to identify genes controlling economically valuable traits, such as those for litter size in the Meishan, and introgress them into nucleus populations. Genes identified from the gene map or from other sources will provide insight into the genetic basis of performance and may provide the raw material from which transgenic programs will channel additional genetic variance into nucleus populations undergoing selection.

• Asian-Australasian Journal of Animal Sciences
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• 제15권5호
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• pp.627-632
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• 2002

Genetic parameters for dairy performance traits were estimated, breeding values for the traits of all breeding sires and cows were predicted and the genetic trends were estimated using the breeding values in the Central Cattle Breeding Station (CCBS). A total of 3,801 records for Bangladeshi Local, 756 records for Red Sindhi and 959 records for Sahiwal covering the period from 1961 to 1997 were used in this analysis. Traits considered were total milk production per lactation (TLP), lactation length (LL) and daily milk yield (DMY). The genetic parameters were estimated by the REML using MTDFREML program. The breeding values were predicted by a best linear unbiased prediction (BLUP). In all sets of data, the genetic trends for the dairy performance traits were computed as averages of breeding values for cows born in the particular year. The estimates of heritability for TLP (0.26 and 0.27) and DMY (0.28 and 0.27) were moderate in Bangladeshi local and Red Sindhi breed, respectively. Furthermore, the heritability estimate for LL (0.24) was moderate in Red Sindhi. The estimates of heritabilities for all traits were low in Sahiwal. The repeatability estimate was high for TLP, moderate for LL and moderate to high for DMY. All variances estimated in Bangladeshi Local were low, comparing the respective values estimated in both Red Sindhi and Sahiwal. On the other hand, additive genetic variances for the three traits were estimated very low in Sahiwal. The genetic trends for the three dairy production traits have not been positive except for the recent trend in Bangladeshi Local.