Direct and Maternal Additive Effects on Rabbit Growth and Linear Body Measurements
Growth and linear body measurements of rabbits which consisted of 17 ew Zealand White (ZW), 19 Chinchilla (CH), 29 ZW x CH and 33 CH x ZW kittens were compared. The aim of the experiment was to evaluate the crossbreeding effects (i.e direct and maternal additive effect) for growth (individual body weight, IBW) and linear body traits (nose to shoulder, TS; shoulder to tail length, STL; heart girth, HG; trunk length, TL; length of ear, LE). Results revealed that significant (P<0.05) general combining ability (GCA) was observed for IBW and TS with ZW rabbits having greater body weight (408.59) and the CH rabbits having better value for TS (11.36). Significant (p<0.05) specific combining ability (SCA) was observed for all the traits evaluated. ZW x CH progenies had better TS (12.05), STL (22.79), HG (16.04), TL (18.59) and LE of ear (8.03) while CH x ZW progenies had better IBW (422.50). Direct additive effect was significant (P<0.01) but negative for all the traits; an indication of minimal contribution of the sires to the inheritance of the traits. Maternal additive effect was observed to be non-significant (P>0.01) for all the traits except IBW. It could be recommended that CH sires be used to mate ZW dams to improve body weight and linear body traits. ZW does could be favoured to give the best IBW based on their superior maternal ability. Crossing between ZW and CH could be advantageous in increasing IBW and linear body measurements.
Keywords: Growth, linear body measurements, heterosis, maternal, additive effect