Comparing different methods for estimating economic values in selection index for pre-weaning body weights of Friesian heifers in Egypt

Abstract EN

This study was carried out to compare different estimates of economic values by different methods as regression (Beta), regression (b), Lamont, Sharma, profit-2004, profit-2012, FAO-2011 and Unity case and their effect on expected genetic gains and possibility of genetic improvement of pre-weaning body weights of Friesian heifers.

Data were collected allover 16 years from 1995 to 2010 and include records of 1748 progeny from 61 sires and 846 dams at the Experimental and Researches Unit of Animal Production (Tokh Tanbisha) in the middle Delta, that belongs to Faculty of Agriculture, Minoufiya University, Egypt.

Selection indices included eight general indices constructed of body weights at birth (W0), 30 (W30), 60 (W60) and 90 (WW) days of age.

Estimates of genetic and phenotypic parameters for studied body weights were computed and used to construct selection indices for improving studied traits in Friesian heifers.

The comparisons of the various selection indices indicated that using Sharma index (I4) achieved to the highest efficiency (RIH=0.5180), but this value was not far from the efficiency of I3- Lamont (RIH=0.5117), I1-regression (Beta) (RIH=0.5051), I5- Profit-2004 (RIH=0.5047), I6- Profit-2012 (RIH=0.5002), and I2- regression (b) (RIH=0.

0.4998).The expected genetic gains per generation for different methods were ranged between 0.6763 and 0.752 kg for W0 , 1.33 and 1.224 kg for W30, 0.863 and 1.1 kg for W60 and 0.886 and 1.043 for WW at (i =1).

It could be suggested that methods of FAO-2011 for being applicable and easy way to estimate economic values by breeders and their desired goals for selection, and multiple regression models, regression (Beta) for its stability and reliability and it takes correlation among selection criterion into consideration.