PASSIVE ACOUSTIC FEEDERS AS A TOOL TO ASSESS FEED RESPONSE AND GROWTH IN SHRIMP POND PRODUCTION

Shrimp production has been one of the most important  sectors of aquaculture for the last few decades  for both its market value and acceptance . As production systems move towards  increasing intensification, animal nutrition takes  a central role as an important growth, environment and health factor. It is well reported that shrimp are opportunistic  grazers that eat a wide variety of organisms, yet  diets with low or no inclusion of fish meal are often s till regarded as of lower quality and a potential cause of less than ideal growth and production.  As the majority of shrimp feeding protocols in typical production setups rely in  a combination of feed trays and  predetermined feed plans, direct assess of shrimp appetite and  feed preferences can be complicated. However, for the  last decade,  development of  passive  acoustic monitoring has allowed a much more direct measurement of shrimp feed intake by capture and integration  of  clicking sounds produced by shrimp while eating.  Tying this to a automated feeding systems has allowed the development of on demand feeding for shrimp. H ence, this technology is a potential tool to help understand  feed preferences when the feeding protoco l is based on real time demand for feed rather than  predetermined quantities.  Building on previous research, the goal of this trial was to  use passive feedback  acoustic feeders as a tool to evaluate if shrimp prefer commercial diets with different protein sources when given the option to eat as much as requested. This 13-wk trial  was performed in 16, 0.1 ha outdoors ponds, stocked at 30 shrimp/m² and equipped with the AQ1  acoustic  feeding system.  All ponds were fed the same  predetermined protocol during the first month after which  acoustic systems were initiated and  four treatments were assigned  with  a 35% crude protein commercial diet with different protein sources: all-plant, 8% poultry meal (PM), 8% fish meal (FM) and 12% FM. Results for this trial are summarized in Table 1.  We did not find any differences in  statistical differences  in any of the main production parameters. Results of this study indicate that shrimp d id not  clearly favor a particular diet. Hence suggesting  that when well balanced commercial feeds and  feed quantity are not a limiting factor ,  shrimp  growth was not highly impacted.