Lauroyl-l-aspartate decreased food intake and body temperature in neonatal chicks

•The effect of emulsifiers on food intake and thermoregulation was studied in chicks.•Lau-L or D-Asp declined food intake while only Lau-L-Asp reduced body temperature.•Lau-L-Asp acted on food intake and thermoregulation, but non-emulsifier did not.

We hypothesized that the effects of l- and d-amino acids might be influenced when conjugated with fatty acid. Thus, the effects of oral administration of lauroyl-l-aspartate (Lau-L-Asp) as well as lauroyl-d-aspartate (Lau-D-Asp) were examined. In Experiment 1, oral administration of both Lau-L-Asp and Lau-D-Asp decreased food intake while L- or D-Asp did not influence food intake. Interestingly, only Lau-L-Asp decreased body temperature. Experiment 2 was conducted to determine whether non-conjugated mixture of L-Asp plus lauric acid has same effects under ad libitum feeding conditions. Lau-L-Asp decreased food intake and body temperature, but L-Asp plus lauric acid did not show any effect studied. In Experiment 3, we found that Lau-L-Asp declined food intake as well as time-dependently suppressed the body temperature in fasted chicks. However, L-Asp plus lauric acid did not show any effect. These results suggest that Lau-L-Asp may exert anorexigenic and hypothermic actions in chicks.