الفهرس 
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Abstract
The present experiment was carried out in the Poultry Farm, Department of Poultry Production, Faculty of Agriculture, Minufiya
University at Shibin El-Kom, Egypt. The local strain used was Sinai
Bedouin fowl. The experimental records lasted for eight years. The
aim of the experiment was to study the response of selection for egg
number at 90 day, egg weight, interval clutches and clutch size by
using the selection index method of laying Sinai hens and compare
different (Five) methods for calculating the economic values in
economic matrices for studied traits.
The following results were obtained as :
1. Overall mean of ASM of Sinai strain was 172.150 d.
2. The overall mean of BWSM of Sinai strain was 1117.505 g.
3. The overall mean of BWM of Sinai strain was 1371.789 g.
4. The overall mean of EWM of Sinai strain was 45.22 g.
5. The overall mean of EN90d of Sinai strain was 55.48 Eggs.
6. The overall mean of EM90 of Sinai strain was 1329.47 g.
7. The overall mean of I of Sinai strain was 2.843 d.
8. The overall mean of C of Sinai strain was 1.607 eggs.
9. Heritability estimates of all studied traits of Sinai strain were
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calculated in addition to the estimates of phenotypic and genetic
parameters in Sinai strain to construct the selection indices which
comprised the following traits:
1) Egg weight (EWM); average weight in g of five eggs from 35
to 38 wk of age.
2) Egg number (EN90d); number of eggs at 90 d of age.
3) Interval (I).
4) Clutch size (C).
10. The relative economic values were estimated.
11. The equations of the general indices which were constructed
for different four economic values:
Kolstad IG = 0.2032 EN90d +0.1094EWM -0.1473 I + 0.5719C.
Reg IG = 0.2326 EN90d + 0.0545 EWM - 0.1189 I 0.0470 C.
Sharma IG = 0.2553 EN90d +0.0860 EWM -0.2501 I + 0.8726 C.
Lamont IG = 0.0079 EN90d +0.3209 EWM -1.103 I +3.014 C.
Soltan IG = 0.03196EN90d -0.0106EWM 0.0992 I +0.1201 C.
12. The standard deviations (I) of these indices were (1.5915,
1.7289, 1.9669, 1.6307 and 0.2419) and its correlations with the
aggregate genotype were (0.4488, 0.4921, 0.4601, 0.3759 and 0.5861)
for Kolstad, Reg, Sharma, Lamont and Soltan, respectively. The
expected genetic changes which would be gained due to applying
these indices of Sinai chickens were +2.1360,+ 2.3960, +2.305, -
0.5971 and +2.635 eggs for egg number till 90 d (EN90d); -0.4779, -
0.7130, -0.6304, 0.9726 and -1.087 egg for weight at maturity (EWM);
-0.0323, -0.0344, -0.0331, -0.0008 and -0.0345 day for interval (I);
and 0.0281, 0.0302, 0.0297, 0.0015 and 0.03104 day for clutch size,
for Kolstad, Reg, Sharma, Lamont and Soltan, respectively.
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13. The equations of the completely I restricted indices (IR, I)
using different economic values which were supposed to stabilize the
performance level of pullets concerning I were:
Kolstad IR, EWM = 0.1529 EN90d + 0.1938 EWM -0.5818 I + 1.3352 C.
Reg IR, EWM = 0.1510 EN90d +0.1913 EWM -0.5856 I +1.2837 C.
Sharma IR, EWM = 0.1733 EN90d + 0.2236 EWM -0.4586 I + 2.1164 C.
Lamont IR, EWM = 0.1129 EN90d + 0.1450 EWM -0.1965 I + 1.4252 C.
Soltan IR, EWM = 0.0154 EN90d +0.0196EWM -0.0592 I+ 0.1419 C.
14. Generally, the results show that the general index (IG) was
most efficient than each of the completely restricted index (IR,EWM) for
Sinai strain. Moreover, a single restriction (IR,EWM) caused less
deterioration in the net efficiency of IG.
15. The sub-index of egg weight at maturity (IS, EWM) which was
developed from the general index (IG) was expected as the most
efficient sub-index to develop egg weight sub-line of Sinai strain.
These sub-indices were:
Kolstad IS, EWM = 0.3107 EWM
Reg IS, EWM = -0.01455EWM
Sharma IS, EWM = 0.03081 EWM
Lamont IS, EWM = 0.2125 EWM
16. The sub-indices of I which were developed from the general
index (IG) were expected as the most suitable sub-indices to improve
this trait in Sinai strain.
Kolstad IS, I = -0.0478I
Reg IS, I= -0.05745 I
Sharma IS, I = 0.003499 I
Lamont IS, I = -0.02047I
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