Recipient Organization
VIRGINIA COBIA FARMS
108 BATTLEGROUND AVENUE
SALTVILLE,VA 24370
Performing Department
(N/A)
Non Technical Summary
Virginia Cobia Farms Phase II USDA-SBIR grant is designed to assist our company at implementing discoveries made during our Phase research I into larger scale production where the process of cobia egg to market size fish production will be integrated into a single interlocking system. Building upon fundamentals established during Phase I, VCF proposes to investigate enhanced brood stock nutrition and its potential impacts upon hatchery output, determine optimal rearing temperatures during hatchery phase of production, establish a multiple grading protocols to increase production efficiencies during grow-out and optimize stocking densities for 1 kg and 2 kg market-sized cobia. This research collectively will produce 2 and 4.4 pound fish for the live market and fillet market, respectively, in RAS consisting of an integrated system of tanks designed as a prototype that will serve as the basis for VCF's large scale expansion scheduled to occur during Phase III. For this Phase II work, VCF will focus on both the production cycle and as well as the quality and consistency of its final product delivered to consumers in the Washington, DC metro area. We will also produce 4.4 pound market size fish for sale as "bullets" (head off gutted fish) to the retail fresh fish market. Continued development and optimization of our in house dietary formulations during Phase II will further the enhance VCF's efficiency and quality control during its rearing of cobia under low salinity conditions in RAS. This proposed Phase II effort will further augment USDA funded efforts awarded to VCF itself or its municipal partner, the Town of Saltville, VA, in the areas of renewable energy generation and rural business development. Successful completion of the Phase II effort will enable VCF to drive its integrated production methods into a modular design format and implement this format in a manner that will both reduce costs and shorten delay times in additional scale up and operations.
Animal Health Component
100%
Research Effort Categories
Basic
(N/A)
Applied
100%
Developmental
(N/A)
Goals / Objectives
Virginia Cobia Farms (VCF) has independently worked through critical bottlenecks at each stage of production, providing not only proof of concept, but also accumulating tremendous amounts of data relating to the biology of cobia and the critical areas of systems design that support the biological findings. The following work plan has been proposes to achieve our Phase II objectives, thus further refining and ultimately producing the optimal, integrated cobia production system for the execution of our business plan. Objective 1: Evaluate cobia brood stock nutrition to increase egg fecundity, fertilization rates and hatchability. Overview: Due our findings with respect to supplemental taurine during Phase I research, as well as related research and development, we know that our standard, wild caught brood stock diet contains approximately 2% taurine. We propose in Objective 1 to investigate the impacts of supplemental taurine on egg quality parameters in cobia broodstock. Objective 2: Optimize hatchery protocols to increase production and size of weaned animals as they leave the hatchery phase. Overview: In Objective 2, we propose to investigate the role of environmental temperature on larval survival during the oil globule stage. It is envisioned that by reducing the culture temperature, the duration of the presence of the oil globule can be increases, thus providing the developing larvae with maternal nutrition for a longer period of time. This should result in higher survival rates, as well as potentially larger fish, at the time of weaning, hence the end of the hatchery phase. Objective 3: Refine juvenile production, incorporating dietary and grading discoveries made in Phase I, to improve specific growth rates, feed conversion ratios and survival through to 100-150 g. Overview: Using our full integration model, we propose that tighter and more frequent grading and culling protocols during the juvenile production stage will result in groups of higher quality juveniles, which in turn, will lead to higher throughput into the production systems. Based upon our Phase I research, we feel confident that improved grading protocols will result in increased production efficiencies when these fish are grown to market size (1 and 2.2 kg) in the grow out systems. Additionally, further optimization of supplemental taurine levels in the juvenile production diets can provide for lower feed conversion ratios, thereby adding to increased production efficiencies. Objective 4: Optimize system design parameters in the production of 1 kg cobia for the live markets and evaluate different stocking densities in the production of 2.2 kg cobia for the filet market. Overview: In this final objective, we propose to increase the stocking densities in the culture of the live market, 1 kg, cobia to 35-40 kg/m3 by further refining our RAS designs and operation. For the 2.2 kg cobia destined for the HOG market, we propose to evaluate two different stocking densities, 30 and 60 kg/m3 during the grow out phase of production.
Project Methods
Objective 1, Experimental Design: Cobia brood stock will be maintained per standard VCF brood stock protocols, but will be fed a diet containing 4% supplemental taurine along with the wild caught diet. This diet will be fed for a minimum of 5 months prior to spawning events. A control tank of equally sized cobia will be maintained so that comparisons with a standard cobia brood diet can be made. After each spawning event, the following parameters will be measured: total number of collected eggs, percent fertilized eggs, egg diameter, oil droplet diameter, hatch rate and size of larvae at hatch. Taurine levels in the eggs, day 3 post hatch and weaned juveniles will be analyzed via HPLC. Objective 2, Experimental Design: Larvae will be stocked out according to established VCF hatchery protocols at day 1 post hatch at a rate of 20 larvae per liter. In one hatchery system containing 6 replicate tanks, the water temperature will be lowered at a rate of 1 C every 2 hours from spawning temperatures to approximately 25 C. The other hatchery system will be maintained at the standard temperature of 28 C according to standard VCF hatchery protocols. Measurements of the oil globule in fish from each treatment will be taken daily until disappearance. Standard lengths of 10 fish per treatment will be taken daily. At weaning, all fish will be counted and survival rates will be calculated. Objective 3, Experimental Design: Juvenile cobia coming out of the hatchery systems will be fed either a standard commercial starter diet or an experimental formulation with supplemental taurine for the next 30 days. At this point, the fish will be graded within their respective dietary treatments into 4 groups, with the smallest grade being culled out of the production cycle. The remaining cobia will be redistributed into the juvenile systems, maintaining their dietary treatments and fed for an additional 30 days. The fish will again be graded, only into three separate grades, with the lower 10% of these fish culled and the remaining fish being transferred into the juvenile rearing tanks for grow out to 100-150 g at a final stocking density of 30 kg/m3. Specific growth rates, feed conversion ratios, and survival rates will be monitored at each 30 day grading period. Hematocrit, plasma taurine levels and liver condition will be evaluated in a subsample of 20 fish per treatment at each grading period. Objective 4, Experimental Design: Cobia from Objective 3 of our Phase II proposal at 100-150 g will be graded, with the middle grade being stocked into each of eight, 11 m3 grow out production tanks. These eight production tanks will represent the 1 kg cobia destined for the live market. The remaining top grade of these fish will be stocked into the remaining four grow out production tanks, two stocked at 30 kg/m3 and the other two at 60 kg/m3. Fish in all production tanks will be fed our in-house proprietary grow out feed formulation. Monthly, a subsample of 100 fish will be weighed from each tank to monitor SGR and FCR. During the monthly sampling events, a subsample of 5 fish from each tank will be sampled for hematocrit, plasma taurine levels and liver index condition.