IN-POND RACEWAY PRODUCTION OF STOCKER AND FOODSIZE HYBRID CATFISH

In-pond raceways systems (IPRS) consist of multiple fixed or floating fish culture units in which aerated water is circulated between the pond and raceways, are stocked at a high density and occupy less than 2 -3% of the pond area. Due to the efficient feed conversion ratio (FCR), effective pond water circulation and more control of the production process, IPRS can support a higher fish yield compared to conventionally managed catfish ponds (8,000 kg/ha) having FCRs above 2.0. In IPRS, annual fish production can be greater than 15,000 kg/ha with FCR's below 1.6. The goal of this study was to verify if hybrid catfish (channel catfish, Ictalurus punctatus, ♀ x blue catfish, I. furcatus, ♂) can be raised in IPRS units to a commercial size (908 g) in one growing season at a yield of 18,000 lb/acre. A large and small floating IPRS unit were placed into each of four 0.4 ha ponds, with the former growing fish to foodsize and the latter growing fingerlings to stocker size (for next year's growout). The growout IPRS raceways in ponds B1 and B2 are 64 m³ (4.9 m x 10.7 m x 1.2 m deep), and 45 m³ (3.1 m x 12.2 m x 1.22 m) in ponds B3 and B4. The fingerling-to-stocker units are 14 m³ (1.8 m x 5.8 m x 1.30 m) and are in ponds B1, B2, B3 and B4, next to the growout units).

Each pond has a total of 5 HP of aeration: a 1.5 and 1.0 HP blowers for the two IPRS units, plus a 1.5 HP and a 1.0 HP blower for the two in-pond water mover-destratification units. Results from the initiation of the trial and partial production results from an August sampling are summarized in Table 1. Fingerlings for the growout units were stocked in April 2018 and for the stocker generator unit in July 2018. They were fed a 35% and 32% CP commercial catfish pellet twice a day. Water quality parameters have been in acceptable ranges. At day 130 sampling showed the estimated biomass almost reached the amount of kgs produced in traditional pond production systems. Total production at the sampling date (stocker weight plus growout weight) were 11,429 kg/ha for B1, 9,721 kg/ha for B2, 9,200 kg/ha for B3 and 10,470 kg/ha for B4 kg/ha, more than the average produced by traditional pond production systems. Full trial results post -harvest will be presented at WAS.