Satiation amount, frequency of feeding and gastric emptying rate in Salmo gairdneri

Abstract

Rainbow trout consumed food in direct proportion to their body weight although the ration increased with temperature. Satiation time varied as 0.031 weight+0.868 temperature+29.145 min. Appetite after deprivation returned in close conjunction with gastric emptying, as judged from serial slaughter studies. Trout trained to operate demand feeders ate less but exhibited feeding rhythms even under conditions of constant illumination. Radiography showed that these rhythms closely paralleled gastric emptying. When offered food diluted with kaolin, the fish compensated by eating more food. This was achieved by increasing feeding frequency caused by a more rapid rate of gastric emptying.