Dietary protein requirements of abalone (Haliotis discus, Reeve 1846) depending on abalone size

Abstract

Dietary protein requirements of abalone (Haliotis discus) depending on abalone size were determined and compared. One thousand and fifty small abalone (initial weight of 2.7 g) and five hundred forty large one (initial weight of 16.0 g) were distributed into 15 and 18 containers in Trial 1 and 2, respectively. Five and six experimental diets containing crude protein level from 20% to 40% and 20% to 45% with 5% increment of protein level for the small and large abalone were prepared and referred to as the CP20, CP25, CP30, CP35, CP40, and CP45 diets, respectively. The experimental diets were fed to abalone for 16 weeks in Trials 1 and 2. Specific growth rate (SGR) of the small abalone fed the CP20 diet was lower compared to that of abalone fed all other diets in Trial 1. Growth performance (weight gain and SGR) of the large abalone fed the CP30, CP35, and CP40 diets were greater than that of abalone fed the CP20, CP25, and CP45 diets in Trial 2. Dietary protein requirements were estimated to be 33.0% and 33.5% for the small and large abalone based on the 2nd order polynomial analysis, respectively. Dietary protein requirements for the small abalone grown from 2.7 g to 7.4 g and the large one grown from 16 g to 21 g were estimated to be 33.0% and 33.5%, respectively. Size differences in abalone did not affect dietary protein requirement under this experimental conditions.