Evaluation of ultra-low gossypol cottonseed and regular glandless cottonseed meals as dietary protein and lipid sources for Litopenaeus vannamei reared under zero-exchange conditions

The current study evaluated transgenic cotton lines with normal levels of gossypol/terpenoids in the vegetative and floral tissues, but with ultra-low gossypol in the seeds as a replacement for glandless cottonseed meal (GCSM) and fishmeal. A 64-day growth trial evaluated the ability of cottonseed meals from a natural glandless cotton variety/mutant, two transgenic Ultra-low Gossypol Cottonseed (ULGCS) lines, a non-transgenic parental control and a commercial variety, to replace 355 g kg^-1 fishmeal in a diet containing 350 g kg^-1 crude protein. Juvenile Litopenaeus vannamei (1.48 ± 0.29 g) were stocked (40 shrimp m^-3) with six replicates. No significant differences were found between all formulated diets in terms of final weight, survival and feed conversion ratio. The commercial cottonseed variety displayed a significantly lower feed efficiency ratio and protein efficiency ratio than one of the ULGCS diets. These results suggest that GCSM and/or transgenic ULGCS meals can be used to replace fishmeal in commercial shrimp diets.