Increasing feeding rates may provide an increase in production, thus nutrients such as nitrogen, phosphorus and organic matter will also increase. These nutrients promote a greater oxygen demand and concentrations of toxic metabolites which can lead to frequent problems with low dissolved oxygen and an abundance of bluegreen algae. Four feed management practices were evaluated among sixteen 0.1 ha ponds culturing Pacific white shrimp (Litopenaeus vannamei). Feeding treatments included hand feeding using the Standard Feeding Protocol (SFP), SFP plus 15% from 8 to 16 weeks, an automatic-solar timer which fed SFP+15%, and an AQ1 acoustic demand feeder allowing up to 12 kg/dayÁpond based on shrimps feeding response. Samples were analysed at weeks 0, 4 and 8-16 for the following parameters: chlorophyll a, total ammonia nitrogen, nitrite-nitrogen, nitrate-nitrogen, total nitrogen, total phosphorus, soluble reactive phosphorus, total suspended solids, total suspended volatile solids, turbidity, conductivity, salinity and biological oxygen demand. Samples were collected and shipped overnight to Auburn, Alabama for offsite analysis. On-site water quality was also obtained at the farm. The AQ1 acoustic demand feeder produced the most shrimp with a yield of 4,568 kg/ha; however, the AQ1 also had the highest total ammonia nitrogen and nitrite-nitrogen levels late in the growing season. The AQ1 feeder may be a viable, reduced labour and cost alternative for the shrimp commercial industry; however, such technologies must also be matched to the ability of the production system to process nutrients.

The purpose of this study was to examine the effects of four feed‐management techniques on the production of Pacific white shrimp, Litopenaeus vannamei, using a 16‐wk trial performed in 16, 0.1‐ha ponds stocked at 17 shrimp/m2. Four treatments were used for this study: standard feeding protocol (SFP) fed twice daily, a 15% increase to the SFP fed twice daily, timer feeders programmed to feed six times daily following the SFP, and ad libitum using the AQ1 acoustic demand feeding system. Significant increases in final weights were seen using the timer and acoustic feeders (28.66 and 35.91 g, respectively) when compared with the SFP and SFP + 15% (23.55 and 24.65 g, respectively). The AQ1 treatment also resulted in a significantly higher shrimp value ($21,198/ha) than the other treatments ($11,776–$13,446/ha). No significant differences were seen in survival (72.2 ± 5.99%), feed conversion ratio (1.03 ± 0.095), or water quality. These results demonstrate that increasing the feed by 15% when feeding twice daily gives no advantage to production. Increasing the feedings from two to six times per day did improve growth and economic returns, and using acoustic feedback to feed based on feeding activity can further improve production and economic returns.

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