Genetic evaluation of economic traits in different generations of synthetic White leghorn strain
Abstract
The data collected from records (2012-13 to 2016-17) of white leghorn strain maintained at the poultry farm of
department of Animal Genetics and Breeding, LUVAS, Hisar were analysed to estimate genetic and phenotypic
parameters, to estimate and study relationship between sire’s breeding values of various economic traits and to
predict 40 weeks egg production from part period egg production and early performance. The effect of
generation and hatch with in generation were significant (P<0.01) on BW20, BW40, AFE, EW40, EM40, EPP1
EPP2, EPP3, EPP4, EP24, EP28, EP32, EP36 and EP40 respectively.
The pooled means for BW20, BW40, AFE, EW40, EM40, EPP1, EPP4, EP24, EP28, EP32, EP36 and EP40 were
observed as 1360.43±7.34 g, 1733.25±12.16 g, 149.90±1.09 days, 52.27±0.27 g, 4269.18±69.26 g,
16.84±0.60 eggs, 20.34±0.27 eggs, 19.15±0.27 eggs, 17.86±0.63 eggs, 7.64±0.76 eggs, 24.47±1.06 eggs,
44.81±1.22 eggs, 63.95±1.44 eggs and 81.79±1.51 eggs, respectively. The heritability estimates for pooled
data were observed as 0.45±0.13, 0.42±0.12, 0.28±0.08, 0.43±0.12, 0.32±0.11, 0.46±0.12, 0.31±0.11,
0.28±0.10, 0.38±0.11, 0.31±0.11, 0.42±0.13, 0.45±0.13, 0.45±0.12 and 0.45±0.13 for BW20, BW40, AFE,
EW40, EM40, EPP1, EPP2, EPP3, EPP4, EP24, EP28, EP32, EP36 and EP40, respectively.
The genetic and phenotypic correlations of BW20 were negative with age at first egg (AFE). The genetic
and phenotypic correlations of body weight at 20 weeks of age with BW40 were significant and high in
magnitude (0.67±0.40 and 0.59**±.02, respectively), however with EW4o and EM40 the correlations were
positive with low in magnitude,EPP1had moderate genetic (0.46±0.17) and phenotypic (0.25**±.02)
correlation with EPP2, while the EPP3 these were moderate at genetic scale (0.37±0.19) and low at
phenotypic scale (0.12*±.02). EPP4 had negligible genetic and phenotypic correlations with EPP1. EPP3 had
high positive genetic correlation with EP24, however, the correlation on phenotypic scale was negligible.
Genetic and phenotypic correlations of EPP3 with EP28 were low positive; with EP32 were moderate positive,
whereas the corresponding correlations with EP36 and EP40 were high positive. The expected direct response
for performance traits were 26.85g, 46.86 g, 1.39 d, 0.44g and 66.97 for BW20, BW40, AFE, EW40 and
EM40, respectively. For part egg production traits direct response ranged from0.39 (EPP3) to o.57 (EPP4)
eggs, whereas, corresponding direct response for cumulative part egg production traits ranged from 0.65
(EP25) to 1.58 (EP40) eggs. The phenotypic trend of all other production, part egg production and
cumulative part egg production showed positive trend. The product moment and rank correlations between
sires’ EBVs for BW20 with those of BW40 were high positive and significant i.e. 0.62** and 0.64**,
respectively. The product moment and rank correlations between sires’ EBVs for EP24 (Egg production upto
24 weeks of age) with all other part cumulative egg production traits were found to be positive significant
with high magnitude. The product moment and rank correlation of performance traits are negligible with
part egg production and cumulative part egg production traits.
The sires’ EBVs for EPP3 and EPP4 had moderate to high positive product moment correlations with sires’
EBVs for all part cumulative egg production traits whereas the corresponding correlations of EPP1 with
these traits were positive with low to moderate in magnitude. The prediction equations were developed by
using stepwise regression procedure for estimation of 40 week egg production based on performance, part
egg production and cumulative part egg production traits. Prediction equation for 40 weeks egg production
showed highest coefficient of determination (90%), when only EP36 was entered in the prediction equation
Description
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