Dietary tocopherol and tocotrienol enhanced the reproductive performance of female red hybrid tilapia (Oreochromis sp.) broodstock.

The effects of dietary vitamin E level and source on the reproductive performance of female red hybrid tilapia, Oreochromis sp., was investigated. Broodstock diets were formulated with added α-tocopheryl acetate (α-ToAc) at 0 (T0), 60 (T60) or 600 (T600) mg per kg diet, which represented sub-optimal, at optimal or ten times above optimal levels, respectively, of vitamin E requirement reported for maximum growth of hybrid tilapia. A fourth diet was supplemented with a palm oil-derived tocotrienols-rich fraction (TRF) designed to contribute α-tocopherol (α-T) at 60 mg per kg diet (PalmE60). TRF consisted of a mixture of co-existing α-T with tocotrienols (T3; 75.5% of total vitamin E). Six pre-spawning female tilapia (individually color-tagged) and two males were placed in each breeding tank. Each diet was fed to two tanks of broodfish for 12 weeks. Irrespective of level or source, vitamin E supplementation significantly improved (P < 0.05) reproductive performance. The average number of eggs produced at each spawning per broodfish was increased by 77.9%, 65.8% and 40.4% when fed T600, PalmE60 and T60, respectively, compared to T0 diet. Absolute fecundity of broodfish fed the T600 or PalmE60 diet was significantly higher compared to the T60 diet. The mobilization of α-T from the peripheral tissues to the ovaries of broodfish fed the T0 or T60 diet confirmed that vitamin E supplementation beyond dietary levels estimated for growth was necessary to optimize spawning performance of tilapia. This is the first report that palm TRF could provide vitamin E to meet the reproductive needs of broodfish.