ABSTRACT

The main objective was the study of genetic variability between three rabbit lines in carcass and meat quality. Rabbits from three synthetic lines were compared. Line V and A were selected for litter size at weaning and line R was selected for growth rate between weaning and slaughter time. Forty animals of each line were slaughtered at 9 week of age. Comparisons between lines were made using Bayesian statistical techniques. Line R had a higher meat/bone ratio and higher loin percentage than A and V, but lower dressing out and lower hind part percentages. Some differences between lines in carcass and meat colour were found. No differences were found for the activity of energy metabolic enzymes.  Meat texture and some biochemical characteristics that could influence meat tenderness were also studied in rabbit loins. The activities of cathepsins, collagen content and textural properties measured by Warner-Bratzler (WB) shear device and by the texture profile analyses (TPA) test were measured. Line R was more tender than line V and line A had an intermediate tenderness. Rabbit meat from line R had higher activity of cathepsins B and B+L, lower total collagen content and lower cohesiveness, springiness and chewiness, shear force and total work (area under the curve obtained with WB device) than line V. Line A had an intermediate texture between lines R and V. A sensory analysis was carried out on Longissimus muscle. The parameters evaluated were: juiciness (J), hardness (H), fibrousness (F), flourness (Fl), intensity of rabbit flavour (IRF), aniseed odour (AO), aniseed flavour (AF), liver odour (LO) and liver flavour (LF). Line V was only an 82% as juicy as line R. Line V was an 18% harder and a 17% more fibrous than line R. Lines A and R had the same H and F. No differences in Fl were found. Small effects were found for flavour traits. Our results show evidence of genetic variation between lines in carcass and meat quality, especially in meat tenderness. The different parameters studied indicate that the meat from rabbits of line R, selected for growth rate is the most tender. As lines were measured at the same age, they are close to the same stage of maturity, thus differences between lines should be attributed to genetic differences.