A comparison of different selection indexes for some economic traits in Holstein Friesian cows

R. Kassab¹, Adeyemi Adenaike², M. Hamed¹, A.E. El- Baraby³, A. Mehrez⁴, A. El-Magd⁴, Abosede Abolude⁵, Sunday Peters⁶^,^*, A. Khattab¹

¹Animal Production Department, Faculty of Agriculture, Tanta University, Tanta 31527, Egypt.

²Department of Animal Breeding and Genetics, Federal University of Agriculture, Abeokuta, Abeokuta 2234, Nigeria.

³Animal production Department, Faculty of Agriculture, Alexander University, Egypt, Alexander 21526, Egypt.

⁴Animal production Research Institute, Ministry of Agriculture, Cairo 12618, Egypt.

⁵Animal Biotechnology Laboratory, Agricultural Research Station, Fort ValleyState University, Fort Valley, GA 31088, United States.

⁶6Department of Animal Science, Berry College, GA 30149, United States.

^*Corresponding Author: Sunday O. Peters, 6Department of Animal Science, Berry College, GA 30149, United States. E-mail: speters@berry.edu.

© Copyright 2024 Korean Society of Animal Science and Technology. This is an Open-Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Received: Jan 12, 2024; Revised: Mar 30, 2024; Accepted: Jun 10, 2024

Published Online: Jun 12, 2024

Abstract

The genetic as well as phenotypic parameters for 10-month milk total (10 MMY), lactation length (LL), and age at first calving (AFC) were calculated with data from 1863 first lactation records of Holstein Friesian cows imported from Germany and managed at a private farm in Egypt between 2002 and 2012. Multiple Trait Derivative Free Restricted Maximum Likelihood was used for the data analysis (MTDFREML, Boldman et al., 1995). Means of 10 MMY, LL and AFC were 9710 kg, 357 days, and 27.17 months, respectively. All the traits examined were significantly impacted by the calving season and year. Heritability estimates for 10 MMY, LL and AFC were 0.37±05, 0.20±0.01 and 0.05±.002, respectively. Four selection indices were calculated by using three different methods of economic values, (1) actual relative economic weight, (2) one phenotypic standard deviation and (3) one genetic standard deviation. Comparison of the three methods for estimating relative economic values revealed no differences in any of the three methods for the expected genetic gain per generation for each trait, the correlation between the total genetic value and the index, or the effectiveness of various indices in comparison to the original index (I<sub>1</sub>). Therefore, the three methods were succeeded in predicting the genetic gain per generation for the three traits studied. However, the second method (one phenotypic standard deviation) was recommended based on ease of calculation.

Keywords: selection index; genetic gain; economic value; heritability; generation interval