Variances of direct and maternal genetic effects for milk yield and age at first calving in a herd of Friesian cattle in Egypt


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KHATTAB A., Atil H. , BADAWY L.

ARCHIV FUR TIERZUCHT-ARCHIVES OF ANIMAL BREEDING, cilt.48, ss.24-31, 2005 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 48 Konu: 1
  • Basım Tarihi: 2005
  • Doi Numarası: 10.5194/aab-48-24-2005
  • Dergi Adı: ARCHIV FUR TIERZUCHT-ARCHIVES OF ANIMAL BREEDING
  • Sayfa Sayıları: ss.24-31

Özet

A total of 2095 lactation records of Holstein Friesian cattle kept at Dalla Farm in Egypt during the period from 1988 to 1992 were used in this study. Those data were used to estimate variances from direct and maternal genetic effects. The data was analyzed by using Multiple Traits Derivative Free Restricted Maximum Likelihood (MTDFREML) according to BOLDMAN et al. (1995) using repeatability Animal Model. Two models were used: Model 1 includes month of calving, year of calving, parity as fixed effects, days open and days dry as covariates and direct genetic, maternal genetic, covariance between direct and maternal genetic, permanent environmental and residual as random effects; Model 2 is similar to Model 1, but excluding additive maternal and covariance between additive direct and maternal effects.