Pasture availability and genotype effect in rabbit: 3. Performance, carcass and meat characteristics.

To verify the effect of pasture availability and genotype on performance and meat quality, 80 weaned rabbits (40 Leprino of Viterbo and 40 New Zealand White) were assigned to two homogeneous groups (sex, weight and genotype): Control (C), reared in standard bicellular cages, and Pasture (P), kept in a wired pen provided of an external grassed pasture area. To evaluate fatty acid composition and tocopherol content of feed and pasture two sampling were carried out and grass was taken from different areas of external paddock. Live weights, feed intake and feed:gain ratio were recorded. At 90 days of age 20 rabbits per group were sacrificed. Respect to feed, pasture showed higher percentage of saturated fatty acids (28.41 vs. 19.67%) and lower of monounsaturated fatty acids (8.00 vs. 19.55%). Regarding polyunsaturated fatty acids, great differences were observed in relation to linoleic and linolenic acids (13.89% vs. 47.25% and 47.72% vs. 11.93%, respectively). Productive performance, carcass traits and fatty acid composition of meat were strongly affected by genotype and housing system. In particular, the possibility of performing movement and ingesting grass caused lower daily gain (Leprino 29.6 vs. 31.9 g; NZW 40.0 vs. 44.2 g) and slaughter weight (Leprino 2418 vs. 2563 g; NZW 2650 vs. 2902 g). Chilled carcasses of pasture reared rabbits followed trend of live weight; bone (Leprino 14.0 vs. 11.6 kg/cm; NZW 14.0 vs. 10.0 kg/cm) and meat (Leprino 3.4 vs. 2.9 kg/cm; NZW 3.4 vs. 2.5 kg/cm) shear force were higher and meat fatty acid profile was richer in n-3 and total polyunsatured fatty acids. Regarding genotype effect, Leprino showed lower daily gains, live and carcass weights. Pasture availability improved the meat nutritional quality and in particular the n-6/n-3 ratio was optimal and the total tocopherols content was suitable to assure a good oxidative stability.