Kentucky State University
Evaluation of Brewers’ Grains at Different Percentages in Combination with Soybean Meal as Partial Replacement of Fish Meal in Diets for Juvenile Nile Tilapia (Oreochromis niloticus)
Institution
Kentucky State University
Faculty Advisor/ Mentor
Kenneth Thompson; James Tidwell
Abstract
Diet costs constitute the largest variable expense incurred during intensive aquaculture production (up to 80% of the operating expenses). Hence, it is essential to evaluate low-cost, nutritionally efficacious diets for further industry expansion and increased profitability for producers. A major trend nationwide has been an increase in the local production of beer. There are now over 2,800 microbreweries in the U.S. After fermentation a significant volume of the byproduct Brewers Grains (BG) is generated. If the brewery were in close proximity to fish production, onsite production of fish feeds would not only save transportation costs, but also a significant amount of energy by using the wet grains rather than drying. Such an opportunity exist in Lexington, KY with Food Chain (Aquaponics) being directly adjacent to West Sixth Brewery. To evaluate suitable levels of BG inclusion, an experiment was conducted with diets containing increasing levels (0%, 24%, 41%, or 66%) of BG. A fifth diet also contained 66% BG plus 1% added lysine to test if that amino acid was limiting. The feeding trial was conducted in 15 (110-L) glass aquaria. Fifteen (15) juvenile tilapia (average weight of 28 g) were randomly stocked into each aquarium with three replicate tanks per treatment (i.e., 5 diets, 3 replicate tanks/diet; 15 tanks total). All diets were formulated to be isonitrogenous (30% protein; as fed basis) and isoenergetic (available energy [AE] = 4.0 kcal/g of diet). After 58 days of feeding, no significant differences (P > 0.05) were found among dietary treatments in terms of average final weight (g), feed conversion ratio (FCR), or percentage survival, with overall means of 89 g, 1.8, and 90%, respectively. In summary, it appears that wet BG might be a suitable ingredient for onsite production of diets for Nile tilapia.
Evaluation of Brewers’ Grains at Different Percentages in Combination with Soybean Meal as Partial Replacement of Fish Meal in Diets for Juvenile Nile Tilapia (Oreochromis niloticus)
Diet costs constitute the largest variable expense incurred during intensive aquaculture production (up to 80% of the operating expenses). Hence, it is essential to evaluate low-cost, nutritionally efficacious diets for further industry expansion and increased profitability for producers. A major trend nationwide has been an increase in the local production of beer. There are now over 2,800 microbreweries in the U.S. After fermentation a significant volume of the byproduct Brewers Grains (BG) is generated. If the brewery were in close proximity to fish production, onsite production of fish feeds would not only save transportation costs, but also a significant amount of energy by using the wet grains rather than drying. Such an opportunity exist in Lexington, KY with Food Chain (Aquaponics) being directly adjacent to West Sixth Brewery. To evaluate suitable levels of BG inclusion, an experiment was conducted with diets containing increasing levels (0%, 24%, 41%, or 66%) of BG. A fifth diet also contained 66% BG plus 1% added lysine to test if that amino acid was limiting. The feeding trial was conducted in 15 (110-L) glass aquaria. Fifteen (15) juvenile tilapia (average weight of 28 g) were randomly stocked into each aquarium with three replicate tanks per treatment (i.e., 5 diets, 3 replicate tanks/diet; 15 tanks total). All diets were formulated to be isonitrogenous (30% protein; as fed basis) and isoenergetic (available energy [AE] = 4.0 kcal/g of diet). After 58 days of feeding, no significant differences (P > 0.05) were found among dietary treatments in terms of average final weight (g), feed conversion ratio (FCR), or percentage survival, with overall means of 89 g, 1.8, and 90%, respectively. In summary, it appears that wet BG might be a suitable ingredient for onsite production of diets for Nile tilapia.