Aquaculture America 2024

February 18 - 21, 2024

San Antonio, Texas

CANNABIS FOR SHRIMP: DIGESTIBILITY OF HEMPSEED MEALS BY Litopenaeus vannamei

Aakriti Khanal*, Kasondra Miller, Waldemar Rossi

Aquaculture Research Center

Kentucky State University

Frankfort, KY 40601

Aakriti.Khanal@kysu.edu

 



Efforts to optimize plant-based diets continue to be a key area in aquaculture nutrition research.  Among traditional and novel protein feedstuffs with potential for use in aquafeeds is industrial hemp. H empseed meal (HSM)  is rich in protein and lipids and might complement other protein sources in feeds for farmed aquatic animals. Nevertheless, information on the nutritional value of HSM for aquatic animals remains limited. 

A digestibility  trial was conducted to assess the nutriti onal value of  two commercially available HSMs for Pacific white shrimp (Litopenaeus vannamei ). Four experimental diets w ere formulated by blending equal portions of a reference diet ( REF; 35% crude protein, 10% lipid) mixture with each of three test ingredients: HSM-P30 (35% CP and 20% lipid), HSM-P50 (45% CP and 23% lipid), and conventional soybean meal (CSBM) at a 70:30 ratio (dry matter basis). Each experimental diet was randomly assigned to four groups of twelve shrimp (10±1.0 g/shrimp) stocked in 16, 110-L glass aquaria operating as a recirculating aquaculture system.  Water quality parameters  were maintained within acceptable ranges for the shrimp.  Shrimp in each aquarium were fed four times daily. Fecal matter w as collected four times throughout the day, discarding the first collection to reduce the effect of coprophagy and intake of other material other than feed, overnight. T o determine the apparent digestibility coefficients (ADCs) for  crude protein, energy, and amino acids ~ 0.3% yttrium trioxide (Y2O3) was used in diet as an indicator.

Based on our results (Table 1),  the CSBM and HSM-P50 diets displayed higher ADC for crude protein compared to REF and HSM-P30, while lower ADC for energy was observed in both HSM diets compared to REF and CSBM (P<0.05). For the test ingredients, higher ADC for crude protein was found in CSBM and HSM-P50 compared to HSM-P30. The highest ADC for energy was found in CSBM, followed by HSM-P50 and HSM-P30 (P< 0.05). The test ingredients also differed in terms of amino acid availability, which will be presented.  Based on our findings, the  HSM proteins are well digested by the  Pacific white  shrimp, while the  lower  ADCs for energy in both HSMs  compared to CSBM might be due to higher fiber content in the former . Overall, our results indicate that HSM can be a good complementary source of nutrients and energy in shrimp feeds.