わが国ホルスタイン種の遺伝学的分析

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書誌事項

タイトル別名
  • Genetic Analysis of the Holstein Breed in Japan
  • ワガクニ ホルスタインシュ ノ イデンガクテキ ブンセキ 1
  • I. Genetic Contributions of Important Breeders and Animals and of Groups of Animals Imported in Different Periods
  • I. 主要ブリーダーおよび種牛ならびに時期別輸入牛の遺伝的寄与

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説明

As the first part of the genetic analysis of the Holstein breed in Japan, with emphasis on the breeding in the last thirty-odd years, per cent genetic contributions of important breeders and important animals, as well as of groups of animals imported during the different five-year periods since 1928, to sample heifers drawn from the pedigree-registrations of 1933, 1938, 1943, 1948, 1953 and 1958 were estimated.<br>It was found that the animals, especially bulls, imported in the early years of 5howa(1928-1937) were overwhelmingly important in the "improvement" of the breed during the last three decades.<br>Several breeders, including the national government, could be regarded as ones that were predominantly important in spreading the genes of those imported bulls aver indigenous animals. It was estimated that more than half of the genes of the 1958 sample heifers were derived from the bulls bred by those breeders. Those breeders, however, have performed a function to multiply imported animals rather than to breed up actually their own animals.<br>Per cent genetic contributions by individual animals in each of the sample years were generally very low. The highest values, mostly for imported bulls, through all the sample years were only about 3 per cent. This means that there has been no such individual as predominated the whole breed. This scattering of values of individual contribution, probably the most marked of all the dairy breeds of which any analysis of this kind has ever been reported, has been brought about because the number of imported animals was fairly large and because important breeders usually used two or more imported bulls contemporarily, instead of linebreeding the whole herd to a single animal.<br>The bulls imported in Japan after World War II have not shown much influence as yet in terms of per cent genetic contribution. There are indications, however, that their contribution will increase very rapidly.

収録刊行物

  • 日本畜産学会報

    日本畜産学会報 33 (2), 187-192, 1962

    公益社団法人 日本畜産学会

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