Effect Of OptiPhos® Plus Supplementation On Growth Performance In Nile Tilapia (Oreochromis Niloticus)

Daniel Arana

The effect of phytate as an antinutritional factor is well-documented, and its impact on phosphorus (P) bioavailability consequently affects the performance and health of fish (van Krimpen et al., 2016). 

Phytase enzymes are crucial in enhancing the bioavailability and release of P and other nutrients bound to phytate. Phosphorus is essential for developing bone structure and plays a key role in several other physiological processes (Tzadik et al., 2017). 

Pragya and colleagues (2021) found that Nile tilapia can only digest around half of the phytate P consumed in their diet. OptiPhos® Plus (phytase enzyme) can be used as a reliable exogenous enzyme to enhance nutrient uptake and growth rate, lowering production costs.

This study shows the positive effect of phytase supplementation in terms of growth performance in Nile tilapia, comparing diets with and without dicalcium phosphate (DCP) supplementation.

 

Materials and methods

A group of 90 Nile tilapia juveniles (Oreochromis niloticus) with an average weight of 5.405 ± 0.045 g were transported to the laboratory of the aquaculture department at Kafrelsheikh University, Egypt. The juvenile fish received a basal diet for two weeks while acclimating.

The fish were randomly assigned to three groups, with each treatment group comprising 30 fish (three replicates/group). Each replicate group of 10 fish was placed in a separate glass aquarium (80 cm x 40 cm x 95 cm) with constant aeration and 50% of water exchange daily.

Experimental design (Table 1): 

  • Group 1: Control group - the basal (low P) diet without addition of DCP or the phytase enzyme
  • Group 2: High P diet (DCP) - the control diet with 0.71% DCP
  • Group 3: Low P + OptiPhos® Plus (LP) - the control (low P) diet + 0.03% of liquid phytase enzyme (LP; OptiPhos® Plus 5000L) to give 1500 FTU/kg diet

 

Table 1. Feed composition. Growth energy was calculated using factors of 5.65, 9.45 and 4.22 Kcal/g of protein, lipid, and carbohydrate, respectively. Nitrogen free extract was equal to 100 - (protein + lipid + ash + fibre)

 

Results and discussion

Fish fed the diet containing OptiPhos Plus at 1500 FTU (LP group) showed improved growth rates (p < 0.05) and feed conversion efficiency (p < 0.05) compared to the fish in the control or DCP group (Table 2). 

In contrast, fish fed the diet supplemented with DCP showed lower growth rates and feed conversion efficiency (p < 0.05) compared to the LP and control group. Additionally, there was significant improvement in growth performance markers such as weight gain rate (WGR) and specific growth rate (SGR) in the LP group.

 

Table 2. Growth performance and survival rate after the 90-day trial. Means within each row with different superscripts (a,b) are significantly different (p < 0.05). BWG = body weight gain, DCP = dicalcium phosphate, FCR = feed conversion ratio, FBW = final body weight, IW = initial weight, LP = liquid phytase, SGR = specific growth rate, SR = survival rate and WGR = weight gain rate

 

In this study, the LP group considerably outperformed the other groups in terms of growth, indicating that receiving OptiPhos Plus at 1500 FTU/kg of feed enhances nutrient assimilation.

The positive findings for growth performance parameters in this study could be attributed to the improved liberation of nutrients by OptiPhos Plus from meals based on plants by dissolving the bonds between phytate-minerals and phytate-protein (Amer, 2017). 

 

Conclusion

  • Using OptiPhos Plus at 0.03% in Nile tilapia diets, without the addition of DCP, enhances growth performance.

 

References are available on request.