Effect of Feeding Rate and Pond Primary Productivity on Growth of Litopenaeus vannamei Reared in Inland Saline Waters of West Alabama

Feeding costs have skyrocketed worldwide in the past several years, negatively impacting shrimp farmers. Typically, 50–60% of the production costs of shrimp farm operations are attributed to feed inputs. The increasing cost of feed combined with declining market prices for shrimp makes it difficult to maintain adequate profit margins. In west Alabama, shrimp farmers are located long distances from feed mills and pay high shipping fees in addition to high feed prices. These low‐salinity waters are quite productive, providing natural food items throughout the production cycle. To determine the possibility of reducing feed rates by relying more on pond primary productivity to contribute to shrimp growth, four growth trials were conducted with juvenile Pacific white shrimp Litopenaeus vannamei (formerly known as Penaeus vannamei). Juvenile shrimp were offered different feed rates ranging from 0% (no feed) to 110% of a normal daily ration by means of static, flow‐through, or partial daily water exchange with water from a production pond. The results revealed no differences in growth among shrimp reared in a flow‐through system and offered feed inputs ranging from 60% to 110% of a daily ration, indicating a contribution of pond primary productivity in the treatments receiving less feed. Static and flow‐through systems were utilized to culture two different size‐classes of shrimp fed at 0, 60, 80, and 100% of a daily ration. The results revealed that shrimp reared in the flow‐through system had better growth and food conversion ratios than those in the static system; however, shrimp in the 0% treatment in the flow‐through system had only slightly inferior performance in terms of growth than those in the 60, 80, and 100% treatments. The results from this study confirm that L. vannamei are capable of obtaining a large percentage of their nutritional needs from pond primary productivity, and farmers should be encouraged to reduce feed inputs, which may enhance profitability.