Multivariate analysis of test day milk yields of British Holstein-Friesian heifers using Gibbs sampling

Firat M. Z., Theobald C. M., Thompson R.

ACTA AGRICULTURAE SCANDINAVICA SECTION A-ANIMAL SCIENCE, cilt.47, sa.4, ss.221-229, 1997 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 47 Sayı: 4
  • Basım Tarihi: 1997
  • Doi Numarası: 10.1080/09064709709362390
  • Dergi Adı: ACTA AGRICULTURAE SCANDINAVICA SECTION A-ANIMAL SCIENCE
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.221-229
  • Anahtar Kelimeler: genetic and phenotypic variance matrices, heritability, multivariate half-sib sire model, test day milk records, VARIANCE-COMPONENTS, GENETIC-PARAMETERS, MODEL, COWS
  • Akdeniz Üniversitesi Adresli: Hayır

Özet

Estimates and posterior distributions of genetic and phenotypic variance matrices for test day milk records are obtained for 23 873 British Holstein-Friesian heifers, the progeny of 40 proven and 649 unproven sires, using restricted maximum likelihood (REML) and Gibbs sampling methods with two different prior specifications in a multivariate sire model. Results from the two methods are then compared. The REML estimates and posterior expectations of heritability and individual test day records range from 0.28 to 0.42. Generally, heritabilities for test day records are lowest at the start and highest in the second half of the lactation. Estimates of genetic correlations between test day milk yields range from 0.59 to 0.99, whilst those of phenotypic correlations are between 0.30 and 0.76, the correlations being highest for adjacent tests. Bayesian inferences are more informative, but require much more computer time.

Estimates and posterior distributions of genetic and phenotypic variance matrices for test day milk records are obtained for 23 873 British Holstein-Friesian heifers, the progeny of 40 proven and 649 unproven sires, using restricted maximum likelihood (REML) and Gibbs sampling methods with two different prior specifications in a multivariate sire model. Results from the two methods are then compared. The REML estimates and posterior expectations of heritability and individual test day records range from 0.28 to 0.42. Generally, heritabilities for test day records are lowest at the start and highest in the second half of the lactation. Estimates of genetic correlations between test day milk yields range from 0.59 to 0.99, whilst those of phenotypic correlations are between 0.30 and 0.76, the correlations being highest for adjacent tests. Bayesian inferences are more informative, but require much more computer time.