الفهرس 
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Abstract
The present study was carried out at the Poultry Research Center of the Poultry Production Department and Central Laboratory of Faculty of Agriculture (El-Shatby), Alexandria University. These data were recorded over six consecutive years during the period (2013-2014), (2014-2015), (2018-2019), (2019-2020(. The study was carried out to evaluate the reproductive traits of maternal line and semen quality of V Line buck rabbits. The main objectives of this study were: 1) To investigate and evaluate the fixed effects of year of birth, month of birth, parity order, gestation length, litter size at birth and sex of animal as internal and external environmental factors affecting productive traits of V-line rabbits (weaning and slaughter weights and post weaning daily gain) under Egyptian conditions, in addition to estimate the regression coefficients of studied traits on age at weaning of rabbits.
2) Estimate the variance components and heritability values for growth and litter traits studied, quantify the genetic and phenotypic correlations among the studied traits. 3) Evaluate the genetic merit (predict the transmitting abilities and genetic trend) of the V Line rabbits and milk yield of a synthetic maternal line of rabbits (V Line) and semen quality of
bucks.
4) Found a positive correlation between the serum gonadotrophin and sex hormones levels at 63 days of age and semen quality characteristics in matiuraty buck rabbits. Linear fixed and mixed models were used for analyzing data. Variance components and heritability estimates were estimated using Restricted Maximum Likelihood (REML) procedure. All recorded traits were determined on rabbits individually. For each mating, the records collected from breeding does were (Doe identification - Date of birth - Sire of the doe identification - Dam of the doe identification - Date of mating - Buck identification - Date of kindling – Number of young born alive - Number of young death at birth - Litter size at weaning - Weaning date). A total of 77, 70 and 70 does were used to estimate milk yield from kindling up to weaning for more than 4 parities. Twenty males of rabbits at 63 days of age were selected random and blood samples were collected to determine serum follicle-stimulating (FSH), luteinizing (LH) and testosterone hormones at the ages of 63 days and 5 and 6 months.