HETEROSIS AND MATERNAL EFFECTS FOR CARCASS TRAITS IN THREE BREEDS OF RABBIT

Authors

  • Kabir, M. Genetics and Animal Breeding Unit, Department of Animal Science, ABU Zaria, Nigeria
  • Akpa, G. N. Genetics and Animal Breeding Unit, Department of Animal Science, ABU Zaria, Nigeria
  • Nwagu, B. I. National Animal Production Research Institute, Ahmadu Bello University, Shika-Zaria,
  • Adeyinka, I. A. National Animal Production Research Institute, Ahmadu Bello University, Shika-Zaria,

Keywords:

Breed, Carcass traits, Heterosis, Rabbits

Abstract

A total of 202, 272 and 256 records for purebred, crossbred and reciprocal-crossbred male and female
rabbits, of three breeds Chinchilla (CHC), Californian White (CAW) and New Zealand White (NZW)
were used in this study. The aim of the study was to estimate maternal, direct additive and heterotic
effects for carcass characteristics in order to identify the best crossbreeding plan to use for rabbit meat
production in Nigeria. Kits used for this experiment belong to 3 parities and were weaned at 35 days of
age. Each rabbit was identified and weighed individually at weaning and at slaughter age (63 days). They
were slaughtered after 18 hours of fasting from feed only. After dissection the dressing percentage was
calculated as carcass weight x 100/live weight. Statistical analyses were performed using the General
Linear Model procedure of SAS. Crossbreeding parameters were calculated from linear contrasts between
breed group means. Results showed that breed differences exist for carcass weight in the purebreds,
where the CHC had significantly (P<0.05) higher carcass weight (1214g) than the NZW (1195g) and
CAW (1174). Pre-slaughter weight, carcass weight and dressing percentage were also affected by breed in
the purebreds and reciprocal crossbreds. Among the reciprocal crossbreds, NZW x CHC had highest
slaughter weight (1711g) while CHC x CAW had the highest carcass weight (1263g) and dressing
percentage (73.9%). Heart, liver, kidneys, lungs and other visceral organs showed no significant (P>0.05)
differences among the breed groups. Estimates of heterotic effect (%H’) calculated for carcass
characteristics in unit and percent (%) for slaughter weight in the CHC x NZW, NZW x CAW and CAW
x CHC crosses were 27.4 and 42%, 25.1 and 29% and 23.7 and 36%, respectively. Examined carcass
traits showed a general insignificant (P>0.05) heterosis. Maternal effects for various carcass traits also
showed no differences in all the crosses except for heart, kidneys and lungs (P<0.05). The maternal effect
herein is conceivably confounded with the reciprocal effect (ie sex linkage) since it is determined as the
difference between the three reciprocal crosses (NZW x CHC, CAW x NZW and CHC x CAW). The
results of this study show that the three selected populations do not seem to complement each other or
aggregate the responsible genes regarding heterotic and maternal effect as well as reproductive efficiency
of the studied carcass traits. Therefore, it can be assumed that the three breeds of rabbit could be used as
dam line for carcass traits.

Published

2016-12-30