Publications (2)4.19 Total impact
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Article: The use of link provider data to improve national genetic evaluation across weakly connected subpopulations.
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ABSTRACT: Data from 3 prefectures and a nationwide farming corporation were used to assess the usefulness of the "link provider data" in providing indirect genetic links for the national genetic evaluation for carcass weight across weakly connected subpopulations of the Japanese Black cattle. The data from the farming corporation provided genetic links to those of all prefectures and was therefore used as the link provider data. Two national genetic evaluation strategies under an animal model were compared, based on the generalized coefficient of determination (CD) of contrasts between mean EBV of sires or maternal grandsires (MGS) from different prefectures: strategy PA-1 was a pooled analysis of the data sets of the 3 prefectures, and strategy PA-2 was a pooled analysis of the data sets of the 3 prefectures and the farming corporation. The CD of the contrasts were greater for PA-2 than for PA-1. Under PA-2, the CD of the contrasts between mean EBV of sires or MGS ranged from 0.67 to 0.78 or from 0.61 to 0.70, respectively. Pooling the data from the 3 prefectures and the farming corporation increased the degree of connectedness through the link provider data rather than the amount of information by adding more data, thus improving the accuracy of prediction. The differences between mean EBV of sires or MGS from different prefectures were smaller for PA-1 than for PA-2. This finding suggests that genetic differences in carcass weight among prefectures are present, but that they would be confused with the environmental differences under PA-1 because of the lack of genetic connectedness among the prefectures. On the other hand, the genetic differences among the prefectures would be predicted precisely under PA-2 because the genetic connectedness among the prefectures was improved by using the link provider data. The results demonstrate that the link provider data could be used to unify within-prefecture evaluation to form a Japanese national genetic evaluation across weakly connected subpopulations.Journal of Animal Science 10/2008; 87(1):62-71. · 2.10 Impact Factor -
Article: Comparison of genetic gains per year for carcass traits among breeding programs in the Japanese Brown and the Japanese Black cattle.
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ABSTRACT: The breeding program for beef cattle in Japan has changed dramatically over 4 decades. Visual judging was done initially, but progeny testing in test stations began in 1968. In the 1980s, the genetic evaluation program using field records, so-called on-farm progeny testing, was first adopted in Oita, Hyogo, and Kumamoto prefectures. In this study, genetic trends for carcass traits in these 3 Wagyu populations were estimated, and genetic gains per year were compared among the 3 different beef cattle breeding programs. The field carcass records used were collected between 1988 and 2003. The traits analyzed were carcass weight, LM area, rib thickness, s.c. fat thickness, and beef marbling standard number. The average breeding values of reproducing dams born the same year were used to estimate the genetic trends for the carcass traits. For comparison of the 3 breeding programs, birth years of the dams were divided into 3 periods reflecting each program. Positive genetic trends for beef marbling standard number were clearly shown in all populations. The genetic gains per year for all carcass traits were significantly enhanced by adopting the on-farm progeny testing program. These results indicate that the on-farm progeny testing program with BLUP is a very powerful approach for genetic improvement of carcass traits in Japanese Wagyu beef cattle.Journal of Animal Science 03/2006; 84(2):317-23. · 2.10 Impact Factor
