الفهرس 
Performance of growth traitsOnly 14 pages are availabe for public view
 |  | from | 189 |  |  |
| | | from | 189 | | |
Abstract
This study extended over 10 generations at the Poultry Research Center, Faculty of Agriculture, Fayoum University: the pre-base, base and the eight generations of selection using a total number of 17,806 Japanese quail chicks:1,300 in the pre-base population, 1,726 in the base population, 10,609 for the selected line (HGR1-21) and 4,171 for the control line (CL) to investigate the consequences of a long term selection for fast growth rate during the period from one to 21 days of age (GR 1-21), evaluate the effectiveness of the selection program applied, estimate the genetic parameters for survival and longevity and to evaluate risk factors with the occurrence of mortality in the two lines of Japanese quail.
The most important results summarized as follows:
Eight generation of selection to augment selection criterion (GR1-21) resulted in remarkable increases in all studied growth traits. The 8th generation had significantly faster GR1-21 than other generations and surpassed the G1 by + 5.29% and favoring the HGR1-21 which exceeded its CL by + 0.03. Except body weight (BW) at hatch, line and sex significantly affected all studied BW’s, body weight gain (BWG), and growth rate (GR) during different growth periods favoring the HGR1-21 than the CL line, and favoring females than males.
The HGR1-21 has shown better performance for all egg and fitness traits than the CL. Either genetic or phenotypic correlation estimates of GR1-21 with correlated growth and egg performance traits were found to be in the favored direction. Therefore, these traits can be indirectly improved through selection for GR1-21 especially those of low heritability. All relative gain values% for all studied traits were consistently in the desirable direction, except for early embryonic mortality% reflecting the effectiveness of the applied selection program in the present study.
Concerning the survival study, both the HGR1-21 and the CL lines had the same risk factors indicating that selection for a high growth rate did not negatively affect survival traits. It can be concluded that continuous selection for high growth rate has resulted in a well-established paternal line of Japanese quail specialized in meat production which can be proposed as a sustainable solution for food security problem.
Key words: long-term selection, early growth rate, growth traits, egg production, relative gain %, survival traits and Japanese quail.