Document Type : Research articles.
Author
Poult. Prod. Dept., Fac. Agric., Fayoum Univ., Egypt.
Abstract
Data of productive performance on a total of 663 mature females :
225 Dandarawi, 296 Fayoumi and 142 Golden Montazah were analyzed to
investigate the possibility to use some blood plasma biochemical constituents
as indicators to egg production-related traits, egg quality, clutch and pause
traits in Dandarawi, Fayoumi and Golden Montazah hens.
Values of heritability obtained for Golden Montazah were larger than
those of other breeds ranged from 0.19 to 0.81 for egg number, egg weight,
egg mass, clutch size, clutch number, pause duration, pause number in the
first 90 days of production (CS90, CN90, PD90, PN90), shape index, plasma
total cholesterol concentrations at 12 weeks of age and peak of egg
production (PTCC12 and PTCCPeak). However, Dandarawi had higher
heritability estimates for yolk index, Haugh unit, shell thickness and plasma
glucose concentrations (PGC) at all ages of measurements. Heritability
estimates for plasma constituents tended to decrease in magnitude as birds
advanced in age which indicating higher variability at earlier ages than that at
later ages of determination.
PTPC12 in Dandarawi and PTCC8 in Golden Montazah were the
most important predictors in attaining AFE. EW90 was negatively affected by
plasma total protein concentration at 8 weeks (PTPC8, R2:2.9%) in Fayoumi.
No influence was detected for any plasma constituents at any age of
measurements studied in Golden Montazah for EW90. The most important
predictor in determining CS90 was PTPC12 in Fayoumi, PTCC12 in
Dandarawi. The corresponding R2 were 3.1 and 6.0, respectively. For
predicting CN90, PTCC12 was the most important significant (P≤ 0.05)
predictors in determining this trait for Dandarawi. However, all plasma
constituents at different ages entered in the model removed for Fayoumi and
Golden Montazah. PTCC12 was found to be positively influencing the PN90
in Dandarawi (R2 : 6.4% and SEE : 4.21) . PGC12 in Golden Montazah was
responsible for explaining 25.6% of the variability in its SI. In Fayoumi,
whereas, PTPC8 positively affected YI in both Dandarawi and Golden
Montazah with R2 of 8.5 and 15.9 % and SEE of 2.38 and 1.82 . Also,
PTPC8 found to be positively affected HU in both Dandarawi (R2 6.0% and
SEE 7.47) and Golden Montazah (R2 13.4% and SEE 7.82). Therefore,
prediction of some productive performance from certain plasma constituents
especially at earlier ages could be estimated from the stepwise regression
models that determine the most important predictors affecting those traits.
Plasma constituents at 8 and 12 weeks in Dandarawi, Fayoumi and Golden
Montazah could be used as selection criteria to improve their productive
performance.
Keywords
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