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| 河原, 孝吉; 後藤, 裕作; 萩谷, 功一; 鈴木, 三義; 曽我部, 道彦. |
| 本分析では, 一般的な方法 (RA) とVanRadenが提案した方法 (VRA) から算出した近交係数を比較検討し, 北海道のホルスタイン集団における近親交配の状況と産乳能力の近交退化および育種価への影響を調査した. 近交係数は, 4,630,163頭の血縁情報を使用し, 再帰的アルゴリズムを用いて算出した. 分析では, 第1に, RAと利用可能なすべての血縁を使用した場合 (RA0), 第2に, RAを使用し, 基礎世代を1950年以前にした場合 (RA50), 第3として, VRAを使用し, 基礎世代を1950年以前にした場合 (VRA50) の3種類の近交係数を算出した. 産乳量の近交退化と育種価は, 1976から2000年8月までに乳期を終了した検定記録から推定した. アニマルモデルには, 近交退化を説明するための偏回帰を含めた. また, 両親の近交係数を使用し, メンデリアンサンプリング分散を補正した. VRA50は, RA50と比較し, 平均近交係数のレベルを高く推定した. RA50とVRA50は, 計算時間の短縮に効果があった. 1960, 1970, 1980, 1990および2000年生まれの雌牛の平均近交係数は, VRA50で各々0.26, 0.56, 1.23, 1.89および4.18%, 種雄牛は各々0.31, 0.43, 0.77, 1.97, および5.14%であった. 1971-1980, 1981-1990および1991-2000年の各期間に生まれた雌牛の年あたり近交係数平均上昇量は, 各々0.07, 0.06および0.22%/年, 種雄牛は各々0.03, 0.12および0.45%/年であった. RA0はVRA50と比較し, 近交退化量を若干低く推定した. 乳量, 乳脂量,... |
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Palavras-chave: Inbreeding coefficient; Inbreeding depression; Breeding Value; Milk production; Holsteins. |
| Ano: 2002 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/2616 |
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| Silva,Mário Henrique Magalhães Araújo da; Malhado,Carlos Henrique Mendes; Kern,Elisandra Lurdes; Daltro,Darlene dos Santos; Cobuci,Jaime Araujo; Carneiro,Paulo Luiz Souza. |
| ABSTRACT The objective of this study was to evaluate inbreeding depression in Holstein cows in Brazil, considering their 305-day milk production (MP), age of first calving (AFC), and calving interval (CI). The effects of inbreeding depression on the traits were determined using four regression models (linear, quadratic, exponential, and Michaelis-Menten) about the errors generated by the animal model. The linear model was significant for CI, and the quadratic model was significant for CI and AFC. The Michaelis-Menten and exponential models were significant for MP, AFC, and CI. Inbreeding depression affected MP and CI. Cows with inbreeding coefficient of 15% produced approximately 260 kg less milk than non-inbred cows. A 1% increase in the inbreeding level... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Calving interval; Inbreeding coefficient; Linear models; Non-linear models. |
| Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982019000100307 |
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| Albuquerque,Daniele Menezes; Oliveira,Carlos Antonio Lopes de; Rodriguez,Maria Del Pilar Rodriguez; Ribeiro,Ricardo Pereira. |
| ABSTRACT The aim of this study was to characterise genetic variability in five groups of Pseudoplatystoma reticulatum: Mato Grosso I (MT-I), Mato Grosso II (MT-II), Mato Grosso III (MT-III), Mato Grosso do Sul I (MS-I) and Mato Grosso do Sul II (MS-II), taken from a centre for genetic improvement. In order to determine the allelic frequency, observed heterozygosity (HO), inbreeding coefficients (FIS), Hardy-Weinberg equilibrium (HW-p) and genetic differentiation, eight polymorphic microsatellite loci (Pcor01, Pcor05, Pcor08, Pcor10, Ppu01, Ppu04, Ppu09 and Ppu10) were selected, in which a total of 62 alleles were observed in the individuals (n = 211). The MS-I population had the highest (Pcor08 allele 83: 0.5000) and lowest (Pcor10 allele 50: 0.1667) mean... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Cachara; Inbreeding coefficient; Allelic Frequency; Population genetics; Microsatellites. |
| Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1806-66902020000100402 |
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