Effects of dietary crude protein levels on growth performance, carcass quality, digestibility and caecal
parameters of crossbred rabbit (local x New Zealand) in Mekong delta of Vietnam

This experiment was conducted on 60 crossbred (local x New Zealand) rabbits started at 7 weeks of age to evaluate effects of dietary crude protein (CP) levels on growth performance, digestibility, carcass quality and caecal parameters of crossbred rabbits (local x New Zealand). The experiment was a completely randomized design with 5 treatments and 3 replications (2 males and 2 females per one experimental unit). The treatments included CP15, CP17, CP19, CP21 and CP23 corresponding to the dietary CP levels of 15, 17, 19, 21 and 23 % with soybean grain supplementation as the protein source. The experimental period was 11 weeks. The results showed that the daily DM (80.3 to 80.9 g/rabbit) and ME (203 to 208 kcal/rabbit) intake, dry matter and organic matter digestibility, and meat nutrients composition were not significantly different (P >0.05) among treatments. However, there were significantly different (Pand ADF digestibility, and caecal N-NH3 and VFA concentration were highest for the CP23 treatment but not significantly different (P>0.05) to the CP21 and CP19. The CP digestibility was highest for the CP19 treatment but not significantly different (P >0.05) to the CP23, CP21 and CP17. The nitrogen retentivity and nitrogen emission (P0.05) to the CP17. The daily weight gain (17.9, 18.7, 19.0, 19.5 and 20.2 g/rabbit for CP15 to CP23 treatment, respectively) and carcass weight were highest for the CP23 treatment but not significantly different (P >0.05) to the CP21, CP19 and CP17. Thus it concluded that the dietary CP level from 17 to 19 % was better for the growing crossbred (local x New Zealand) rabbits in the Mekong delta.

Keywords: Growing crossbred rabbits, performance, nutrients utilization, crude protein