AUTOMATIC FEEDERS SCHEDULE AS A TOOL FOR IMPROVEMENT OF SHRIMP Litopenaeus vannamei PRODUCTION SYSTEMS IN PONDS
Shrimp are regarded as slow feeders with preference for many small meals . Various studies have shown improved growth and production as the number of feedings increases. With the move to automated feeding systems the number of feedings can be greatly increased and labor reduced. Technological development has presented shrimp industry with an increasing number of on-demand (satiation) feeding systems. Building on previous research, a 90- day pond trial was designed to test shrimp productivity under different feeding schedules and rations. The production trial was conducted in 16, 0.1 ha outdoors ponds, stocked at a 35 shrimp/m2 , and fed a 35% protein soy-optimized feed. Standard ration for timer-feeders (SRTF) was calculated based on a standard ration (SR) which is based on an expected weight gain of 1.3 g/wk , a feed conversion ratio (FCR) of 1.2, and a weekly mortality of 1.5% during growout period. All ponds were fed the same amount of feed for the first 30 days after which f our treatments were initiated including SR160 Daytime, SR1 60 Nighttime, and SR175 24 hours which were fed using automatic timer-feeders, and a fourth treatment utilized on-demand AQ1 acoustic feeding system (AQ1). The first three treatments were feeding increasing percentages of SR equally until Day 75 , Day 30-45 fed SR130%, Day 45-60 fed SR145% , Day 60-75 fed SR160%. The 24h treatment ration was increased to SR175% for Day 75-90 and the other two stayed at SR160%. Preliminary one-way ANOVA and Student-Newman-Keuls test results presented in Table 1 indicate that AQ1 System application resulted in statistically higher feed inputs which resulted in higher yields. However, on-demand feeding system did not result in larger shrimp nor higher weekly weight gain that shrimp fed SR 160 during Daytime. Timer-feeder treatments with nighttime and 24 hours feeding schedule had lower feed input than daytime as consequence of providing meals during the period of the night in which oxygen availability is typically lower, consequently meals were skipped more often to avoid critically low oxygen levels. Further analysis will be performed and presented at the conference.
