Aquaculture Africa 2023

November 13 - 16, 2023

Lusaka, Zambia

EFFECT OF NANOSILVER SUPPLEMENTED DIET ON GROWTH PERFORMANCE AND THE EXPRESSION OF IMMUNE GENES IN Labeo rohita INFECTED WITH Aeromonas carviae

Omoniyi Michael POPOOLA1,2*  and Bijay Kumar BEHERA2

 

1 Department of Fisheries and Aquaculture Technology, Federal University of Technology, Akure, Nigeria.

2 ICAR-Central Inland Fisheries Research Institute, Barrackpore, Kolkata-700 120 West Bengal, India

 



 The rapid development in food fish production has effect on the health  of cultured  species with potential stressors and infectious diseases.  There is need developing novel feeds and formulations with fresh perspectives and distinctive traits, such as silver nanoparticles (AgNPs ). These nanoparticles are strong bactericidal substances that work in low doses as growth promoters and immunological boosters.  The impact of nanosilver (AgNPs ) supplemented diet on the immune system, and growth performance of Labeo rohita infected with A. carviae was examined in this study.

 L rohita (n:180; av wt 55.20 ± 0.04 g) were randomly grouped into four treatments (three replicates/treatment, 15 fish/tank); a control diet without the addition of AgNPs served as the basis for the other three diets, with each contained 10, 15, and 20 µg kg-1 of the AgNPs throughout a 52-day feeding period.  Isolation of total RNA from fish kidneys, liver, and muscle was done using TRIzol , Nanodrop, and RNAse -free DNAse I. Synthetic cDNA was reverse-transcribed into first-strand cDNA and diluted to 750 ng/mL. Reference primers were IL-10, 5 -CTGTGAAGGCATGGGTGTG-3 / 5’ ATCACTTTCTTCACCCAGGG-3’, and TNF-.5’-CAAGCAATTGGCGAGTGTGT-3’/5’-CAGTTCCACTTTCCTGATTACTCTGA -3’ β-actin was used as reference gene .

 The fish in the 15 µg kg1 group had better growth performance and a considerably higher (P< 0.05) relative percentage survival (RPS, 70%) after the  A. carviae challenge (Table 1). TNF- expression in the liver was considerably higher (P < 0.05) in T3 than those in other treatments, with T4 having the highest levels of TNF-α and IL-10. IL-10 levels in the muscle rose significantly (P< 0.05) in T2, T3, and T4, and IL-10 levels in the kidney, gills, and muscle were all elevated (P< 0.05) (Fig. 1) .

 This research finding suggests that AgNPs can beneficially influence fish growth, and control  A. carviae infection by enhancing the immune response of  L. rohita.

 Table 1 . Growth and survival of Labeo rohita given various levels of AgNPs.

Diets

(µgKg-1 )

Initial weight (g)

Final weight (g)

Weight gain (WG%)

FCR

Survival (%)

0 (control)

29.28±0.01a

44.37±0.31d

55.63±3.14d

2.09±0.10a

80c

 10

30.22±0.02a

57.12±0.29b

89.01±3.20b

1.62±0.10c

90b

 15

30.78±0.03a

59.49±0.34a

93.27±4.67a

1.48±0.11d

100a

 20

29.98±0.05a

51.89±0.29c

73.08±2.47c

1.79±0.12b

90b

The values reflect the mean and standard deviation consisting of three duplicate groups. The mean values with contrasting superscripts differ significantly (P< 0.05).

Fig. 1  Relative transcription of IL-10 and TNF-α genes in Labeo rohita Kidney, muscle, gill and liver fed various amounts of dietary silver nanoparticles and infected with  A. carviae  (AgNPs). The transcript levels were normalized against β-actin. (The mean values with contrasting superscripts differ significantly (P< 0.05).