Animal Breeding and Genetics
Animal Breeding and Genetics
Staff
 | Assoc. Prof. Dr.Takayuki IBI E-mail： ibi-t＠（@okayama-u.ac.jp） Specialty： Animal Breeding and Genetics Investigating invisible genetic events using statistical and molecular genetics analysis |
Research Topics
The aim of animal breeding and genetics is to investigate invisible genetic events using statistical and molecular genetics analysis. Then we can understand the genetic structure of a population and the genetic features of an animal, which is useful for designing an optimum breeding program. In particular, we are interested in genetic analysis of reproductive traits in Japanese Black cattle, the genetic diversity in the animal population and theory of QTL (Quantitative traits locus) analysis. Through our research activity, young scientists are encouraged to acquire the necessary knowledge and techniques to pursue scientific careers in quantitative genetics in the post-genome era.
Genetic parameters for calf mortality in Japanese Black cattle
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The Japanese Black cattle is the predominant beef breed in Japan. In Japan, calves are sold at action, so, the death of calves is an economic loss for the reproductive farm. In spite of the economic importance of calf mortality, studies of the genetic parameters of calf mortality are few. Because, calf mortality is not a continuous trait such as body weight, but a threshold trait, classified only as live or dead. However, in recent years, the genetic parameters of threshold traits can be analyzed. Therefore, we investigate the genetic parameters of calf mortality in Japanese Black cattle. |  |
Genetic parameters for reproduction traits in Japanese Black cattle
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In recent years, Japanese Black cattle have been selected mainly for their meat quality, especially the degree of (intramuscular) marbling. In practice, genetic improvement for meat quality is very high. On the other hand, fertility performance is falling. Therefore, it is very important for genetic improvement of fertility performance to investigate the genetic parameters for reproduction traits and the genetic correlation between reproduction traits and carcass traits in Japanese Black cattle. Moreover, we investigate the genes responsible for reproduction traits with another institute. |  |
Genetic diversity in Japanese Black cattle
As mentioned above, genetic improvement for meat quality in Japanese Black is very high. A small number of elite sires with high estimated breeding values for meat quality have been intensively used. As a result, the effective population size of the breed has decreased during recent decades. Therefore, the increase of the effective population size to maintain the high levels of genetic diversity is important for maintaining future breeding options in this breed, since genetic diversity is essential for maintaining selection response to increase productivity and to adapt to economic and environmental changes. Therefore, we investigated the genetic diversity of Japanese Black cattle using genetic markers.
Publication List
- K. Oishi, T. Ibi, A. K. Kahi and H. Hirooka. (2011) Optimal culling strategy in relation to biological andeconomic efficiency and annualized net revenue in the Japanese Black cow–calf production system. J. Agr. Sci. 149, 783-799.
- T. Munim, T. Oikawa, T. Ibi, T. Kunieda and Md. A. Hoque. (2012) Genetic variability of maternal effect on body measurements and its intra- and inter-genetic relationship with direct effect in Japanese Black calves. Anim. Sci. J. 83, 199-206.
- T. Munim, T. Oikawa, T. Ibi and T. Kunieda. (2013) Genetic relationship of body measurement traits at early age with carcass traits in Japanese Black cattle. Anim. Sci. J. 84, 206-212.
- T. Nishimaki, T. Ibi, Y. Tanabe, Y. Miyazaki, N. Kobayashi, T. Matsuhashi, T. Akiyama, E. Yoshida, K. Imai, M. Matsui, K. Uemura, N. Watanabe, T. Fujita, Y. Saito, T. Komatsu, T. Yamada, H. Mannen, S. Sasazaki and T. Kunieda. (2013) The assessment of genetic diversity within and among the eight subpopulations of Japanese Black cattle using 52 microsatellite markers. Anim. Sci. J. 84, 585-591.
- S. Sasaki, T. Ibi, T. Watanabe, T. Matsuhashi, S. Ikeda and Y. Sugimoto. (2013) Variants in the 3' UTR of General Transcription Factor IIF, polypeptide 2 affect female calving efficiency in Japanese Black cattle. BMC Genet. 14, 41-51.
- S. Sukegawa, T. Miyake, T. Ibi, Y. Takahagi, H. Murakami, F. Morimatsu and T. Yamada. (2014) Multiple marker effects of the single nucleotide polymorphisms in three genes, AKIRIN2, EDG1 and RPL27A, for marbling development in Japanese Black cattle. Anim. Sci. J. 85, 193-197.
- S. Sasaki, T. Ibi, S. Ikeda and Y. Sugimoto. (2014) A genome-wide association study reveals a quantitative trait locus for age at first calving in delta/notch-like EGF repeat containing on chromosome 2 in Japanese Black cattle. Anim. Genet. 45, 285-287.