DIRECT AND PERCENT HETEROTIC EFFECTS ON BODY WEIGHT AND REPRODUCTIVE TRAITS IN TWO BREEDS OF RABBIT

Abstract

This study was conducted to evaluate the effect of reciprocal crossing on body weight (BW) and reproductive characteristics of two breeds of rabbits, New Zealand white (NZW) and chinchilla (CHA) raised in tropics. Offspring from the crossing of NZW x CHA and CHA x NZW were studied for body weight (BW) and reproductive traits for twelve weeks. Reproductive traits studied were litter size at birth (LSB), litter size at weaning (LSW), Average birth weight (ABWT), Average weaning weight (AWWT), Gestation length (GSTL) and percent mortality. The heterotic values and their percentages were calculated in the two genetic groups using the linear contrast procedure. The direct and percent heterosis for reproductive traits were all positive for the two genetic groups except in gestation length and percent mortality which showed negative heterorosis (-1 and -3.2%; 3.19; 10.12% for gestation length and -7.19 and -19.07; -9.36 and -24.83% for percent mortality in CHA X NZW and NZW X CHA respectively). Body weight at different ages studied were positive for NZW x CHA offsprings while CHA x NZW offsprings had negative values for all these parameters measured indicating that CHA sired offsprings had no improvement for BW at various ages. It could therefore be concluded that rapid improvement in these traits (Reproductive and body weight) could be achieved by crossbreeding involving mating of New Zealand White male and Chinchilla does in the study area.