Productive and reproductive traits improvement of the Egyptian local strain rabbits by the crossing with two foreign strains

الملخص EN

The numbers of 1317 parities were analyzed to evaluate crossing effects among three breeds of rabbits.

The tested breeds were New-Zealand White (NZW), Chinchilla (Ch) and Gabali (G).

An incomplete dialed crossing mating design excluding the two reciprocal crosses between the two foreign breeds (♀Chx♂NZW, ♀NZWx♂Ch) was adopted.

The traits studied were litter size (LS) at birth (LSB), litter size at 21 days (LS21) and litter size at weaning (LSW), litter weight (LW) at birth (LWB), litter weight at 21days (LW21) and litter weight at weaning (LWW).

As well as, growth traits involved: individual body weight (BW) at 4 (BW4), 6 (BW6), 8 (BW8), 10 (BW10) and 12 (BW12) weeks of age.

In addition, heterosis (HI) was estimated for all traits studied.

Effect of mating type was significant (P < 0.05) for LS, LW and BW traits.

In purebreeds, G rabbits recorded the highest value of each (P < 0.05) LSB, LS21 and LSW (7.3, 5.9, and 5.8, respectively).

In crossbreed, results showed that ♀Gx♂Ch recorded the highest value of each LSB, LS21 and LSW (7.5, 6.1, and 5.9, respectively).

With respect to LW traits, in purebred rabbits, G recorded the highest LWB (411.9 g), while NZW recorded the highest LW21 and LWW (1745.4 and 2824.4 g, respectively).

In crossbreeds, ♀Gx♂Ch showed the highest LWB (394.2 g), while ♀NZW x♂G recorded the highest LW21 and LWW (1836.5, 2917.1 g, respectively).

♀ New Zealand White x ♂Gabali rabbits and ♀Chx♂G rabbits recorded negative and non-significant estimates of heterosis (%) for LS and LW traits.

Individual body weight traits were significantly influenced by mating type during the different ages.

Both ♀NZWxG♂ and ♀ChxG♂ rabbits recorded positive and significant estimates of heterosis (%) for BW traits.

Based on the results of the present study, it could be concluded that crossing between G does and Ch bucks improved LS and/or LW traits.

Also, crossing between G bucks and NZW does improved growth traits, LWB and LW21.