ASSESSMENT OF CARCASS TISSUE COMPOSITION IN GROWING RABBITS USING REAL TIME ULTRASONOGRAPHY

Background. Carcass yield varies depending on the relative proportions of muscle, fat and bone, therefore, the possibility of predicting its value would produce valuable information that will promote the viability and sustainability of rabbit meat production. Methodology. Thirty-eight male growing rabbits (New Zealand White × Californian) with body weights (BW) of 1329 ± 291 g and from 60 to 100 days of age were used. Real time ultrasonography (RTU) measurements were taken 12 h before slaughtering. For that, rabbits were shaved between the 6th and 7th lumbar vertebrae. The longissimus thoracis et lumborum muscle (LM) area (LDA) and also the maximum LM width (LDW) and the maximum depth LM (LDD) were measured. Data recorded at slaughtering included carcass and non-carcass components. After chilling at 4° C for 24 hours, carcasses were split longitudinally to obtain left and right halves that were later weighed. Thereafter, the right half carcass was weighed and manually deboned for recording weights of muscle (TCM), and bone (TCB). Results. The highest correlation (r = 0.84, P <0.001) was observed between TCM and LDD, while the lower correlation (r = 0.4, P <0.001) was observed between TCB and LDW. The BW were highly related to carcass characteristics (r>0.77≤0.97). In vivo RTU measurements explained a low to moderate amount of variation in TCB and TCM with an r2 of 0.36 to 0.77 (P < 0.001) respectively. BW explained from 49 to 92% of variation in TCB and TCM, respectively. Implications. The in vivo ultrasound measurements it is a viable tool that allows predicting carcass value of rabbits. Conclusion. Our results indicated that the use of RTU measurements could accurately predict muscle from growing rabbit's carcass.