Effects of aflatoxin B1 on reproductive performance of farmed Nile tilapia

Esther Marijani,Harrison Charo-Karisa,Gbemenou Joselin Benoit Gnonlonfin,Emmanuel Kigadye,Sheila Okoth

doi:10.1080/23144599.2019.1678315

Abstract

ABSTRACTThis study evaluated the effect of dietary aflatoxin B1 (AFB1) on growth, milt and egg quality in matured Nile tilapia (Oreochromis niloticus). Triplicate groups of Nile tilapia (initial body weight 24.1 ± 2.6 g) were fed with either of four diets (Diets 1 to 4) designed to contain 0, 20, 200 and 2000 μg AFB1 kg−1 diets for 24 weeks. After 24 weeks of AFB1 exposure, growth was significantly (P <0.05) different between the control and the AFB1 exposed treatments in both sexes. No significant differences were observed in 17β-oestradiol, absolute fecundity, oocytes volume and diameters between AFB1 exposure groups and the control group. However, we observed a significant reduction in relative fecundity and gonad somatic index (GSI) in females fed 2000 μg AFB1 kg−1 diet. On the other hand, we observed significant differences (P <0.05) in gonadosomatic index (GSI), testosterone, milt count and motility between males in the control group and AFB1 treatments. We conclude that rearing Nile tilapia with aflatoxin-contaminated diets for a prolonged period affects milt quality, fecundity (at higher doses) and growth performance. This implies that for optimal seed production, provision of aflatoxin free diets should be part of the management practices in Nile tilapia hatcheries.

Highlights

Nile tilapia (Oreochromis niloticus) is East Africa’s most cultured fish species and is farmed under a range of semi-intensive and intensive systems [1]
Considering that toxic effect of AFB1 depends on the dose in the feeds as well as sex and the age of animal [15], we examined whether males and females of Nile tilapia exhibit differences in their growth response to dietary AFB1 contamination
Mean final weight of male Nile tilapia was affected by AFB1 whereas the final mean weight of exposure groups was lower than that of control group (Table 2)

Summary

Introduction

Nile tilapia (Oreochromis niloticus) is East Africa’s most cultured fish species and is farmed under a range of semi-intensive and intensive systems [1]. It is known for rapid growth, tolerance to high stocking densities and poor water quality, high reproductive rates and low susceptibility to disease. The use of plant-based ingredients in aquafeeds is increasing. Plant-based ingredients are very susceptible to aflatoxin contamination at different stages of the agricultural chain such as pre-harvest, harvest and post-harvest handling. Feeds are the possible source of aflatoxin exposure of farmed Nile tilapia [2]

Methods

Results

Discussion

Conclusion