Evaluation of three feeding strategies on the culture of white shrimp Penaeus vannamei Boone 1931 in low water exchange ponds

Three feeding strategies (feeding tables (FTA), feeding trays (FT) and complementation of natural food (CNF)) for white shrimp farmed in earthen ponds were evaluated in an experimental study conducted during 15 weeks at Bahia Kino, Sonora, northwestern Mexico. Significant differences (p < 0.05) in growth were found between the treatments, with the best weight gain in treatment FT (13.22 g) and the worst in FTA (8.43 g). Intermediate results were obtained in treatment CNF (11.52 g). The yield showed the same tendency (2996 kg/ha, 2768 kg/ha and 2030 kg/ha for treatments FT, CNF and FTA respectively). No significant differences in survival were observed between treatments (p > 0.05). The lowest feed conversion ratio (FCR) was 1.59:1, obtained in treatment CNF. It was not significantly different (p > 0.05) from that obtained in treatment FT (1.69:1). Both were better than the FCR observed in treatment FTA: 2.39:1. Morning dissolved oxygen was significantly lower in treatment FTA (p < 0.05) than in treatment CNF. Organic matter in sediment, biological oxygen demand, phosphates, nitrates, nitrites and ammonia were significantly higher in treatment FTA (p < 0.05). According to these results, feeding trays or complementation of natural food seem to be better feeding strategies than feeding tables for the commercial culture of the white shrimp Penaeus vannamei. (C) 1998 Elsevier Science B.V.