Supplemental Feeding of Tilapia in Fertilized Ponds

Abstract

The addition of feed to fertilized fish ponds was evaluated by adding feed alone, feed plus fertilizer, or fertilizer alone to nine ponds stocked with Nile tilapia Oreochromis niloticus. Two experiments were conducted. The first had 500 fish per 250 m2 pond in 3 treatments: ad‐libitum feeding; fertilizer only; or fertilizer and ad‐libitum feeding. The second experiment had 5 treatments with 750 fish per pond ad‐libitum feed only; fertilizer only; or 0.25, 0.50, and 0.75 satiation ration plus fertilizer. Ponds in Thailand were maintained for 155–162 d, during which chemical and physical properties were monitored. In experiment 1 tilapia growth was highest in feed only ponds, and lowest in fertilizer only ponds. Net yield did not differ significantly among treatments, due to variation in survival. In experiment 2, tilapia growth was lowest in fertilizer only ponds, intermediate in 0.25 ration ponds, and highest in 0.50, 0.75, and ad‐libitum ponds. The latter treatments were not significantly different. Multiple regressions for each experiment indicated only 47–87% of the variance in growth was explained by feed and fertilizer input, while 52–89% of the variance in yield was explained by those factors. For both experiments combined, 90.3% of the variance in growth was explained by feed input, fertilizer input, alkalinity, and total inorganic nitrogen concentration. For yield, R2 was 0.888 and the regression included feed input, pH, and number of low dissolved oxygen events. Experiment 1 appeared to approach carrying capacity near the end, while no reduction in growth occurred in experiment 2 at higher fish density and biomass. Reductions in growth in experiment 1 were not correlated with declining water quality late in the grow out. Combinations of feed and fertilizer were most efficient in growing tilapia to large size (500 g) compared to complete feeding or fertilizing alone.

Comparative Growth Performance of Mixed-Sex and Monosex Nile Tilapia Population in Freshwater Cage Culture System under Indian Perspective

“…Moreover, hormone treatment can increase the SGR and DWG of the fish. Similar values of individual growth for monosex tilapia, as in our study, were also observed by Diana et al (1991Diana et al ( , 1994. It has been observed that for a given food composition, the body protein percentage on a wet weight basis is mainly affected by the body weight in salmonids (Shearer 1994).…”

“…The higher growth rates of control males compared to control females (Table 1) might be due to increased energy being channeled towards metabolic maintenance and somatic growth in males while the females use considerable energy for spawning (Tran-Duy et al 2008). The growth curves of mixed-sex and monosex fish in cages were more or less linear ( Figure 1A) indicating that the critical standing crop in cages was not exceeded (Diana et al 1994) possibly due to the addition of supplemented food. A few studies have demonstrated the enhanced yield of monosex male Nile tilapia populations under experimental conditions (Mair et al 1995).…”

Growth, Yield and Returns to Koi, Anabas testudinous (Bloch, 1792) under Semi-intensive Aquaculture System using Different Seed Types in Bangladesh.

“…Vietnam koi increased the SGR and daily weight gain of the fish. Similar values of the individual for Vietnam koi as in the study were also observed by Diana et al [47].…”

Produccion de tilapia nilotica (Oreochromis niloticus L.) utilizando hojas de chaya (Cnidoscolus chayamansa

“…En otros estudios se ha tratado de incrementar la producción acuícola mediante la combinación adecuada de fertilización, alimento balanceado y/o granos (Diana et al, 1994;Green et al, 2002;Liti et al, 2006). Sin embargo, prácticamente no se ha evaluado el efecto productivo de reducir el uso del alimento balanceado complementado con alimentos de origen vegetal y de forma cruda, a baja escala.…”