This work aimed to evaluate the effectiveness of the indirect
selection by using certain plasma constituents at 8 and 12 weeks of
age to achieve an advantageous change of the target productive
traits in three local breeds of chickens: Dandarawi (Dand),
Fayoumi (Fay) and Golden Montazah (GM). Breed significantly
(P≤ 0.01) affected plasma constituents regardless of age of
measurements. Fay had significantly higher PG and PTC than
other breeds (200.65 and 108.20 mg/100ml) whereas GM had the
lowest PTC of 88.91mg/100ml. Dand had the highest PTP being
6.38mg/100ml. Age of measurements significantly affected either
PTP or PTC while, its effect on PG was insignificant. Higher PTP
at 12 than 8 weeks of age was shown whereas the PTC was
significantly higher at 8 weeks of age than 12 weeks of age (6.46
vs 5.69 and 109.79 vs 96.94 mg/100ml, Table 1). Significant breed
by age of measurement interaction (P≤ 0.01) effects on PG, PTP
and PTC were found. There were inconsistent breed differences
either in magnitude or direction in the expected correlated
responses in egg production-related traits and each of clutch size
and pause traits to future selection. Therefore, plasma constituents
at 8 and 12 weeks in Dand, GM and Fay can be used as selection
criteria to improve their productive performance. So, the more
than unity efficiencies indicated indirect selection for target
productive traits through selection for plasma constituents at
certain studied ages which was more efficient than the direct
selection for improving these traits. However, direct selection for
productive traits will be the most efficient method for improving
these traits if their efficiencies were lower than unity.