Abstract
The objective of the study was to improve productivity of Aradi goat breed (A), for milk production traits through crossbreeding with the imported Damascus goats (D). Milk yield and composition were measured biweekly from kidding up to the 24th weeks of lactation. Direct additive genetic effects, direct heterosis, maternal heterosis, and direct recombination effects were determined. Crossbred goats showed improved milk yield and components compared to the local Aradi purebred. The estimates of direct heterosis expressed as percentages relative to parental purebreds showed a range of 3.1 to 6.9% for milk traits. Estimates of direct additive effects for milk traits were significantly higher in favour of Damascus goats by 31.7%. The estimates for milk components were mostly insignificantly in favour of Damascus goats for fat, SNF, protein, lactose and ash. Crossbred goats were associated with significant heterotic improvements for daily milk yield, fat, SNF, protein and ash.