Single-feeding response of chinook salmon fry to potential feed intake modifiers

A study was conducted to determine the effects of various potential feed intake modifiers on initial feed consumption by spring chinook salmon (Oncorhynchus tshawytscha). Feed intake was immediately and significantly influenced when glycine, trimethylamine, or betaine was added to experimental diets. Results support the notion that glycine enhances feed intake, whereas trimethylamine and betaine decrease it. The reduced consumption of diets containing betaine, which has often been described as a feeding attractant, may have been a response to the chemical form of this compound used in this study (betaine hydrochloride) and may not occur if the free form of betaine is used.