Indian Journal of Poultry Science
Year : 2004, Volume : 39, Issue : 1
First page : ( 54) Last page : ( 56)
Print ISSN : 0019-5529.

Phenotypic and genetic response in primary and various correlated traits in White Leghorn layers

Devi K. Sakunthala, Scientist, Reddy P. Mahipal, Principal Scientist

AICRP on Poultry Breeding, Rajendranagar, Hyderabad - 500 030 (AP).

Received:  24  May,  2003; Accepted:  11  December,  2003.

Abstract

Change in the mean performance of WLH population under the influence of constant selection over six generations was evaluated. The traits studied were Age at first egg, Egg weights and Egg production at 40 & 64 weeks ofage. The phenotypic and genetic response revealed that the Age at first egg declined gradually from base generation to the current generation. The phenotypic response of Age at first egg was -1.5 days in IWD and -0.80 days in IWF strain, where as the genetic response was estimated as 0.17±0.14 and 0.21±0.28 days respectively. The phenotypic response of egg weight was negative estimated as -0.61 and -1.58 gms respectively. The genetic response was 0.57±0.17 gms in IWD strain and 0.23±0.13 gms in IWF strain. The phenotypic response ofegg production at 40 and 64 weeks in IWD was 4.3 and 6.6 while in IWF strain 3.7 & 6.5 eggs respectively. Corresponding genetic response were 0.16±0.24 & 0.15±0.21 eggs in IWD and 0.58±0.51 & 0.08±0.09 eggs in IWF strain. These values indicated that as the egg number increases egg weight showed a declining trend. There was significant increase in number of eggs produced from base generations to the current generations in both the strains.

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Key words

Phenotypic and genetic respose, traits, White Leghorn.

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