Journal cover Journal topic
Archives Animal Breeding Archiv Tierzucht
Journal topic

Journal metrics

Journal metrics

  • IF value: 0.991 IF 0.991
  • IF 5-year value: 1.217 IF 5-year
    1.217
  • CiteScore value: 2.0 CiteScore
    2.0
  • SNIP value: 1.055 SNIP 1.055
  • IPP value: 1.27 IPP 1.27
  • SJR value: 0.425 SJR 0.425
  • Scimago H <br class='hide-on-tablet hide-on-mobile'>index value: 28 Scimago H
    index 28
  • h5-index value: 13 h5-index 13
Supported by
Logo Leibniz Institute for Farm Animal Biology Logo Leibniz Association
Volume 50, issue 4
Arch. Anim. Breed., 50, 327–336, 2007
https://doi.org/10.5194/aab-50-327-2007
© Author(s) 2007. This work is distributed under
the Creative Commons Attribution 3.0 License.
Arch. Anim. Breed., 50, 327–336, 2007
https://doi.org/10.5194/aab-50-327-2007
© Author(s) 2007. This work is distributed under
the Creative Commons Attribution 3.0 License.

  10 Oct 2007

10 Oct 2007

Estimates of genetic parameters for test day milk yields of a Holstein Friesian herd in Turkey with random regression models

Ç. Takma and Y. Akbaş Ç. Takma and Y. Akbaş
  • Ege University, Faculty of Agriculture, Department of Animal Science, Biometry and Genetics Unit, İzmir, Turkey

Abstract. Genetic parameters for test day milk yields of Holstein Friesian cows have been estimated using a random regression model (RRM). Data consisted of 1487 monthly test day milk yield records of cows calving between 1987 and 1993 in Sarmısaklı Farm, Turkey. Data were restricted to have at least 150d and at maximum 308d length of first lactations.

Additive genetic and permanent environmental (co)variances were modeled with the same order polynomial regressions. Residual (measurement) error variance was assumed to be constant throughout lactation. The quadratic (k=3) order orthogonal polynomial regression was found to be sufficient. Heritability estimates for test day milk yields were high at the middle of the lactation and ranged from 0.07 to 0.32. Genetic correlations of milk yields between consecutive test days were high, but decreased as the interval between tests days increased. Genetic correlations ranged from 0.51 to 0.99. Residual error variance was estimated 13.77 kg.

Download
Citation