| Registro completo |
| Provedor de dados: |
OAK
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| País: |
Japan
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| Título: |
Investigation of genetic and environmental factors for test day milk yields on each stage of lactation for holstein cattle in Hokkaido
乳牛の各泌乳ステージにおける検定日乳量に影響を及ぼす諸要因の検討
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| Autores: |
増田, 豊
鈴木, 三義
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| Data: |
2008
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| Ano: |
2008
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| Palavras-chave: |
Environmental effect
Genetic parameter
Lactation curve
Test day milk yield
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| Resumo: |
乳牛の各泌乳ステージにおける検定日乳量に関して，環境効果の大きさおよび遺伝的パラメータを推定し，各要因の泌乳パターンへの寄与について調査した．データは(社)北海道酪農検定検査協会により1989年1月から2006年7月までに集積された初産および2産牛からの検定日記録，ならびに日本ホルスタイン登録協会北海道支局が保持する血縁情報であった．泌乳ステージは分娩後6日から30日間隔で設定した．牛群・分娩年は乳期を通して泌乳量の変動を最も説明したが，分娩月齢および分娩年月による変動は相対的に小さかった．遺伝率は初産において0.19から0.35，2産において0.12から0.29の範囲にあった．牛群・分娩年および分娩年月による泌乳曲線を説明するには，高次の多項式関数が必要であった．相加的遺伝曲線を説明するには，両産次とも2次のLegendre多項式で十分であったが，泌乳パターンは産次によって異なることが示された．
The objectives of this paper were to estimate the influence of environmental factors and genetic parameters on test day milk yields on each stage of lactation and to investigate the contribution of these effects to pattern of lactation curve for dairy cattle in Hokkaido. Data included 8,419,665 and 6,253,857 test day records from 849,349 and 630,978 Holstein cows calving between 1989 and 2006 collected by Hokkaido Dairy Milk Recording and Testing Association for first and second lactation, respectively. The pedigree information was provided by Holstein Cattle Association, Hokkaido Branch. Stages of lactation were defined at 30 days intervals from 6 day in milk. Herd-year of calving accounted for 30 to 49 percent of total sum of squares. However, age of calving and month-year of calving explained a relatively small variation. Heritability estimates ranged from 0.19 to 0.35 and 0.12 to 0.29 for first and second lactation, respectively. Lactation curves nested within herd-year and year-month of calving needed higher order polynomials. Eigenvalues and eigenvectors for additive genetic covariance functions showed that second order Legendre polynomials were enough to account for describing variability for additive genetic curve in each lactation but pattern of the curve differed by parity.
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| Idioma: |
Japonês
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| Identificador: |
http://ir.obihiro.ac.jp/dspace/handle/10322/2603
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| Editor: |
日本畜産学会
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| Formato: |
application/pdf
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| Direitos: |
日本畜産学会
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