Dietary effects of cottonseed protein concentrate substituting fishmeal on the growth and flesh quality of Pacific white shrimp (Litopenaeus vannamei)

The present study aimed to investigate the dietary effects of replacing fishmeal (FM) with cottonseed protein concentrate (CPC) on the growth, flesh quality and gossypol residue of Pacific white shrimp (Litopenaeus vannamei). Based on a diet containing 560 g/kg FM, CPC was used to replace 0%, 20%, 40%, 60%, 80% and 100% of dietary FM with CPC inclusion of 0, 130.2, 260.4, 390.7, 521 and 651.3 g/kg, respectively (CPC0, CPC20, CPC40, CPC60, CPC80 and CPC100). Then, the six isoproteic diets were used to feed shrimp with initial body weight of 1.20 ± 0.05 g in low salinity water (0.5–1.0‰) for 56 days. The results showed that the growth performance of shrimp was not significantly affected by the replacement of 20%, 40% of dietary FM with CPC (P > 0.05). Compared to the control, the weight gain was decreased by 15.1%, 21.7% and 33.8% (P < 0.05), while feed conversion ratio was increased by 0.15 (P > 0.05), 0.18（P < 0.05）and 0.23 (P < 0.05) in CPC60, CPC80 and CPC100 groups, and the meat yield were also significantly decreased in the three groups. Flesh water holding capacity, hardness, chewiness, SOD activity, free flavor amino acid and heat insoluble collagen contents of CPC80 and CPC100 groups were significantly lower, while flesh MDA content was significantly higher than those of the control group. There were no significant differences in flesh proximate composition, amino acid composition and free gossypol content among all the groups. In conclusion, in a diet containing 560 g/kg FM, CPC could successfully substitute 40% of dietary FM, and higher substitution decreased the growth performance and flesh quality of Pacific white shrimp.