Influence of dietary replacement of soybean meal with crawfish shell meals on the growth, skin coloration and muscle texture of Oujiang color common carp (Cyprinus carpio var. color)

An 8-week growth experiment was conducted to investigate the effects of different levels of crawfish shell meals ( Procambarus clarkii, CSM) replacement of soybean meal (SM) on growth, feed utilization, antioxidant response, body color and muscle quality of Oujiang color common carp (3.0 ± 0.5 g , Cyprinus carpio var . Color ), and to assess the suitable range of CSM replacement of soybean meal and its effects on fish. Three isonitrogenous and isolipidic experimental diets were formulated to replace SM by equal proportion (1:1, w: w) of CSM at 0, 25, or 50 % (designated as CSM0, CSM25, or CSM50, respectively). The results showed that weight gain (WG) as well as hepatic superoxide dismutase (SOD) activities were significantly ( P < 0.05) higher in the CSM25 group compared to the CSM0 group. In addition, there were no significant ( P > 0.05) differences in growth performance, feed utilization, skin color, and muscle texture parameters between CSM50 and CSM0 groups, except for the overall ash content, which was significantly ( P < 0.05) higher in CSM50 than CSM0 group. Therefore, it was feasible to replace 50 % of SM with CSM in Oujiang color common carp diets without negative effects on serum biochemical indices, antioxidant and immune responses, skin color or muscle texture. These findings suggested that CSM could be a potential alternative protein source in diets of Oujiang color common carp. • 25% crawfish shell meals (CSM) significantly increased weight gain rate and antioxidant enzyme activity. • Replacing up to 50% of the soybean meal with CSM had no adversely effect on the growth performance. • Replacing up to 50% of the soybean meal with CSM had no adversely effect on the skin color and muscle texture.