Evaluation of purebred and crossbred rabbits for carcass merit

Abstract

Two hundred twenty-six fryers representing four breed types, New Zealand White (NZW) and Californian (CAL) purebreds, CAL x NZW (CxN), and Flemish Giant (FG) terminal crossbreds (the latter group including FG x CAL, FG x CHA [CHA = Champagne D'Argent], and 1/2FG x 1/4CAL x 1/4CHA), were appraised for carcass merit. Evaluation criteria included the following: preslaughter and carcass weights; pelt, visceral, giblet, abdominal fat, and dressing percentages; percentages of carcass in loin, forequarter, and hindquarter primal cuts; and weight of lean in loin and ratio of lean to bone weight in loin cut. The least squares model consisted of breed type (B), season of birth (S), and gender (G) as fixed effects, B x G and S x G interactions, litter within B and S as a random variable, and random residual. Breed type influenced (P less than .10) all traits except giblet and forequarter cut percentages. Season of birth significantly influenced all all traits except percentage of loin cut. Gender of rabbit affected (P less than .05) only the percentage of forequarter cut. A B x G interaction was observed (P less than .05) for pelt and visceral percentages. The NZW control purebreds were generally inferior (P less than .05) to the three other breed types for carcass yield and cutability traits. Purebreds were lighter for preslaughter, carcass, and loin lean cut weights and lower for loin lean-to-bone ratio than were CxN crossbreds (P less than .05). The FG crossbreds had heavier preslaughter and carcass weights and a lower abdominal fat percentage (P less than .01) than NZW, CAL and CxN. Results of this study provide corroborative evidence in support of terminal crossbreeding using CAL sires with NZW dams and FG purebred or crossbred sires with CAL and CHA purebred or crossbred dams to improve carcass merit.