A crossbreeding study was carried out at the Experimental Rabbit Farm,

Department of Animal Production, Faculty of Agriculture, At-Azhar University, Nasr

City Cairo, Egypt, for three consecutive years of production starting from September

1998, using Bauscat (exotic breed) and Baladí Red (local breed) ¡n addition to their

two reciprocal crosses to study direct heterosis, maternal additive and diret additive

effects on progeny traits (body weight and daily gain). Breed group effects on body

weight were non-significant at different stage of ages, while its effects on daily gain

weight were found to be significant at age intervals of (8-10), (10-12), (12-14) and (4-

14) weeks of age. Threr was a superiority of Bauscat rabbits over Baladi Red for body

weight at studied all age except at 10 weeks, while for daily gain weight ¡t was during

all age intervals except at (5-10) weeks. however the differences between the two

breeds were mostly non-significant for body weight and daily gain traits.

Crossbreeding between Bauscat and Baladi Red rabbits was generally associated

with improvement in all body weights and daily gain weight traits except body weights

at 12, 14 weeks and daily gain during ages intervals of (8-10), (10-12) and (4 —14)

weeks. Direct Sire additive effect on progeny traits were mostly ¡n favour of Bauscat

sired rabbits progeny traits except body weight at 14 weeks and during the age

interials of (8-10), (10-12), (12-14), (birth-14) and (4-14) weeks it was in favour of

Baladi Red sires. Maternal additive effect on progeny traits was in favour of Baladí

Red rabbits for most studied body weight traits. When crossbreeding was applied

between these two rabbit breeðs Maternal additive effect on daily gain was ¡n favour

of BR dams during the age intervals of (birth-4), (4-6) and (6-8), while daily gain

during intervals of (8-10), (10-12), (12-14), (birth-14) and (4-14) weeks were in favour

of B dams.

Keywords: Egyptian Balad Red rabbits, crossbreeding, Heterotic effect,

maternal additive effect, direct additive effect.

INTRODUCTION

Crossbreeding has an advantage over the synthesis of breeds ¡n

utilizing the breed differences due to the expected segregation along with the

recombination (Dickerson, 1969). Egyptian studies (e.g. Afifi, 1971; Afifi and

Khalil, 1989; Oudha, 1990; ElDessokì, 1991; Afifi et aL, 1994; Khalil et at,

1995 and Abd El-Aziz, 1998) evidenced, ¡ri general, that crossing local

breeds of rabbits (e.g. Baladi, Baladi Red, Baladi Black, Giza White, ..etc.)

with exotic breeds (e.g. Bauscat, Californian, New Zealand White, ... etc.)

was associated with improvement in progeny traits ( e.g. body weight and

daily gain weight). Several studies were carried out to investigate the

productive potentialities of native and exotic breeds of rabbits under the

Egyptian conditions, in spit of this results there is a need to obtain more

information about the genetic, environmental and managerial aspects of

rabbit production to create a profitable industry. In addition to estimate the

present objectives direct heterosis (H'), direct(G5 and maternal (G') additive