Journal cover Journal topic
Archives Animal Breeding Archiv Tierzucht
Journal topic

Journal metrics

IF value: 0.991
IF0.991
IF 5-year value: 1.217
IF 5-year
1.217
CiteScore value: 2.0
CiteScore
2.0
SNIP value: 1.055
SNIP1.055
IPP value: 1.27
IPP1.27
SJR value: 0.425
SJR0.425
Scimago H <br class='widget-line-break'>index value: 28
Scimago H
index
28
h5-index value: 13
h5-index13
Supported by
Logo Leibniz Institute for Farm Animal Biology Logo Leibniz Association
Volume 56, issue 1
Arch. Anim. Breed., 56, 455–466, 2013
https://doi.org/10.7482/0003-9438-56-044
© Author(s) 2013. This work is distributed under
the Creative Commons Attribution 3.0 License.
Arch. Anim. Breed., 56, 455–466, 2013
https://doi.org/10.7482/0003-9438-56-044
© Author(s) 2013. This work is distributed under
the Creative Commons Attribution 3.0 License.

  10 Oct 2013

10 Oct 2013

Estimation of genetic parameters for daily milk yields of primiparous Iranian Holstein cows

K. Kheirabadi1, S. Alijani1, L. Zavadilová2, S. A. Rafat1, and G. Moghaddam1 K. Kheirabadi et al.
  • 1Department of Animal Science, University of Tabriz, Tabriz, Iran,
  • 2Institute of Animal Science, Prague-Uhříněves, Czech Republic

Abstract. Applying a multiple trait random regression (MT-RR) in national level and for whole test day records of a country is a great advance in animal breeding context. Having reliable (co) variance components is a critical step in applying multiple traits genetic evaluation especially in developing countries. Genetic parameters of milk, fat and protein yields were estimated for Iranian Holstein dairy cows. Data included 276 692 test day (TD) production traits records collected of 30 705 primiparous cows belonging to 619 sires. An animal multi-trait random regression model was employed in the analyses using the restricted maximum likelihood (REML) method. The model included herd-test-date, age-season of calving (by applying a fixed regression for each subclass of this effect) and year of calving as fixed effects and random regression (RR) coefficients for additive genetic (AG) and permanent environmental (PE) effects. Obtained results showed that daily heritabilities ranged from 0.10 to 0.21 for milk, from 0.05 to 0.08 for fat and from 0.08 to 0.18 for protein yield. Estimated heritability for 305-d milk, fat and protein yields were 0.25, 0.20 and 0.25, respectively. Correlations between individual test day records within traits were high for adjacent tests (nearly 1) and decreased as the interval between tests increased. Correlations between yields of milk, fat and protein on a given test day are also high and greater during late lactation than during early or mid-lactation. Genetic correlations between 305-d yield traits ranged from 0.75 to 0.92. The largest genetic correlation, as well as permanent environmental correlation, was observed between milk and protein yield.

Download
Citation