New peer review article on the interest of Nor-Feed Citrus limon extract on nile Tilapia performances.

Feed efficacy, a main pilar for

Nile Tilapia Production

Nile tilapia (Oreochromis niloticus L.) is one of the main species of fish cultivated in the world, especially in developing countries located in Africa, South America, and Asia (FAO, 2022). It is a fish species capable of optimizing food conversion to weight gain, which fillet consumers appreciate.

In general, Nile tilapia production occurs in intensive systems, and feed efficacy is a pilar to meet the metabolic demands generated by such production practices.

Can Nor-Spice AB® improve the growth of

Nile Tilapia?

This study aimed to investigate the effects of dietary supplementation with Nor-Spice AB® on the growth, hematological, and biochemical parameters of Nile tilapia juveniles. Six diets with different levels of Nor-Spice AB® in the diet:

Level 1: 0.0 g/kg^-1(control)
Level 2: 0.2 g/kg^-1
Level 3: 0.4 g/kg-1
Level 4: 0.8 g/kg-1
Level 5: 1.6 g/kg-1
Level 6: 3.2 g/kg^-1

These 6 different levels of Nor-Spice AB® were evaluated for 60 days, followed by 8 days of Aeromonas hydrophila challenge. They were injected with 0,2 ml of a 10⁷ CFU/ml. Fish were fed normally for 8 days. Mortality was measured by group on the 8th day.

Field trial results

Proven efficacy

Figure 1: Average weight gain of Nile tilapia after 60 days of treatment. Different letters indicate a statistical difference between treatments

Figure 2: Cumulative mortality rates of Nile tilapia challenged by inoculum of Aeromonas hydrophila strain for 8 days. Different letters indicate a statistical difference between treatments (Duncan test, p < 0.05). N = 30 fish per treatment.

Results showed a positive effect of the increasing (up to 1.6 g/kg^-1) inclusion of Nor-Spice AB® on final weight, weight gain (Fig 1), feed intake, feed conversion ratio, and perivisceral fat index.

After bacterial infection, quadratic regression showed that Nor-Spice AB® reduced mortality of juveniles (Fig 2).

This study demonstrates the positive effects of the graded inclusion of Nor-Spice AB® on zootechnical performances on juvenile Nile tilapias grown in unchallenging conditions. They also underline its interest when fish are challenged with a pathogenic bacteria.