Combined feeding frequency and ration size effects on juvenile Litopenaeus vannamei performance fed diets supplemented with fish hydrolysates

Optimum feed ratio and frequency ensure maximum growth and efficient feed utilization in all feeding management strategies. Thus, the present study evaluated the effects of feeding frequency and ration restriction on juveniles of Litopenaeus vannamei (0.8 ± 0.06 g) fed two diets over 53 days. Feeding frequency included two (10:00, 16:00) and four times a day (10:00 h, 16:00, 22:00, 04:00 h), using isonitrogenous diets (35% protein) formulated with fish hydrolysates produced via external (FHEE) or internal (FHIE) enzymes. Feed was supplied at 100% and 80% of apparent satiation. At the end of the experiment, survival was not different among treatments (p > 0.05). Shrimp fed twice showed a significantly higher weight gain than those fed four times (6.27 ± 0.42 vs. 5.76 ± 0.38 g, respectively); feed conversion ratio (FCR) was also higher (1.86 ± 0.16 vs 1.71 ± 0.18, respectively) but not significantly different (p > 0.05). The results demonstrated an improved feed efficiency at 80% compared with 100% satiation (FCR = 1.64 ± 0.07 vs 1.93 ± 0.12, respectively), which was achieved at growth expense (5.79 ± 0.31 vs 6.23 ± 0.51, respectively). No differences in weight gain were observed when comparing the distinct types of diets (FHEE or FHIE). The primary outcomes of the present study indicate a detrimental effect on reduced ration size growth at 80% without any benefits of increasing feeding frequency at night hours. The results of the present study also highlight the impact of apparent satiation and daylight feeding schedules in juvenile L. vannamei .