Time-Of-Day of Feeding Affects Growth, Fattening, and Serum Hormone Levels in Channel Catfish

<p> Channel catfish Ictalurus punctatus were maintained on a 12L:12D photoperiod,</p><p> 20&ring; &plusmn; 1&ring;C, and received one of two commercial diets either early (0730 h), late (1600 h), or at both times of day (feeding rate 2.5 g% body weight/day). After 6 weeks of feeding, body weight, body length, abdominal fat weight and mean serum cortisol and thyroxine levels (determined by radioimmunoassay) differed among feeding regime groups depending on the diet, time-of-day of feeding and/or fedding frequency. There were also diel variations in serum cortisol and thyroxine titers; the pattersn of serum cortisol and thyroxine differed with diet and time-of-day of feeding, respectively.</p>