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

Authors: RICHARDSON, CRISTINA - Agrilife Research; SICCARDI III, ANTHONY - Agrilife Research; PALLE, SREENATH - Texas A&M University; CAMPBELL, LEANNE - Texas A&M University; Puckhaber, Lorraine; Stipanovic, Robert - Bob; WEDEGAERTNER, TOM - Cotton, Inc; RATHORE, KEERTI - Texas A&M University; SAMOCHA, T - Texas A&M Agrilife

Submitted to: Aquaculture Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/16/2014
Publication Date: 2/3/2016
Citation: Richardson, C.M., Siccardi III, A.J., Palle, S.R., Campbell, L.M., Puckhaber, L.S., Stipanovic, R.D., Wedegaertner, T.C., Rathore, K.S., Samocha, T.M. 2016. 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. Aquaculture Nutrition. 22:427-434.

Interpretive Summary: Dietary protein for aquaculture raised shrimp is traditionally composed of fishmeal and soybean meal. Marine fishmeal is a limited and diminishing resource that threatens sustainability of aquaculture. Cottonseed meal is a readily available and underutilized and heavy metal free source of protein. Cottonseed meal contains the naturally occurring toxin, gossypol. Cottonseed meal derived from plants that do not produce gossypol in the seed and foliage can be fed to shrimp, but these plants are very susceptible to attack by many insects, even those that do not normally attack cotton. Thus, these plants are not widely cultivated. However, transgenic cotton plants that have normal levels of gossypol in the foliage, but ultra-low levels in the seed have been developed. Cottonseed meal from these ultra-low gossypol cottonseed (ULGCS) plants or from commercial cottonseed meals was incorporated into a shrimp diet to replace 35.5% of fishmeal. 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.

Technical Abstract: Our previous studies showed that glandless cottonseed meal (GCSM), produced from naturally occurring mutant plants, can replace 67-100% of fishmeal in shrimp diets without any negative effects on the growth and survival of shrimp. However, glandless cotton plants, completely lacking protective gossypol and related terpenoids, are susceptible to pests and pathogens, and therefore are not grown extensively. 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 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 fishmeal in a 35% crude protein diet. 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.