Identification of feeding stimulants for striped bass, Morone saxatilis

A series of experiments were conducted to screen amino acids and other compounds, presented individually or in mixtures, as feeding stimulants (FS) for striped bass. Two bioassays (experiment series A and B) were conducted. The FS carrier in series A was a nutritionally complete plant feedstuff-based diet whereas in series B, the basal was an agar-gel matrix. The second bioassay proved to be the more sensitive testing and delivery system. Striped bass had a maximum response to the neutral amino acids, and particularly to l-alanine and l-serine. Inosine-5′-monophosphate and betaine were the only non-amino acid compounds that elicited a significant positive response. All combinations tested of l-alanine, l-serine, inosine-5′-monophosphate and betaine stimulated feed intake for striped bass, the maximum response being attained when all four compounds were included together in the feed. Additive and/or synergistic effects between the compounds may have accounted for the enhanced response of the mixtures.