POSTWEANING PERFORMANCE OF TWO NEW ZEALAND WHITE LINES AND THEIR RECIPROCAL CROSSES FED A HIGH FORAGE DIET

Abstract

Thirty-five day old weanling rabbits from two New Zealand White genetic lines, Mexican (MX) and Oregonian (OR) and their reciprocal crosses, paternal Mexican (MO) and paternal Oregonian (OM), were used to evaluate growth performance based on high forage, alfalfa-orchard grass (AO) or commercial diet (CO). One hundred and twenty eight rabbits were used in a 4x2 factorial (genotypes x diets) repeated measurement (week) experiment. Response variables were: body weight (BW), average daily gain (ADG), feed intake (Fl), feed conversion (FC), dressing weight percentage (DW) and postweaning mortalily (MT). The diet effect was important for BW (P<0.01), ADG (P<0.01) and FC (P<0.05), wilh a superior performance by rabbils on the CO diet. Means for final 10 week BW (g), ADG (g) and FC were, 1983±45, 1722±44; 32±2, 28±2; and 3.8±6, 4.4±4, for the CO and AO diet, respectively. The genotype was not important for growth variables and showed no heterotic effect. The FI ranged from 105±5 to 112±5 g/d for genotypes, and from 107±4 to 109±4 for AO and CO diets. For DW differences were observad among genotypes, wilh the OR showing the poorest performance (P<0.05). Means were 49.2±1.5, 48.4±2.0, 45.6±2.2 and 43.9±2.9 for MX, OM, MO and OR. No signfficant differences were observad for MT, but cumulative mortality by week 10 by genotype was 12.5, 9.4, 9.4 and 6.3% for MX, OR, MO and OM. The OR and crossbreds tended to have better survival. For CO and AO diets, mortality means were not different (10.9 and 7.8%).