International Journal of Aquaculture, 2017, Vol.7, No.16, 106-110
106
Research Report
Open Access
Growth Performance and Nutrient Utilization of Hormonal Sex-reversed Male
and Mixed Sex
Oreochromis niloticus
under Outdoor Rearing Condition
S.O. Olufeagba, Victor Tosin Okomoda , T. Adoga
Department of Fisheries and Aquaculture, University of Agriculture, Makurdi, Nigeria
Corresponding author Email:
International Journal of Aquaculture, 2017, Vol. 7, No.16 doi:
Received: 07 Sep., 2017
Accepted: 09 Oct., 2017
Published: 20 Oct., 2017
Copyright © 2017
Olufeagba et al., This is an open access article published under the terms of the Creative Commons Attribution License, which permits
unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Preferred citation for this article
:
Olufeagba S.O., Okomoda V.T., and Adoga T., 2017, Growth performance and nutrient utilization of hormonal sex-reversed male and mixed sex
Oreochromis
niloticus
under outdoor rearing condition, International Journal of Aquaculture, 7(16): 106-110 (doi:
Abstract
This study investigates the performance of all male and mixed sex tilapia (
Oreochromis niloticus
) raised in outdoor
rearing conditions. All male tilapia were obtained by hormonal administration of 17 α-methyltestosterone (30 µg) into the diet of
hatchlings of
O. niloticus
and fed them for 28 days. Both sex-reversed male and mixed sex
O. niloticus
were fed with coppens
®
commercial diet and replicated thrice at 45% crude protein for 24 weeks Biological evaluation such as Mean Weight Gain (MWG),
Specific Growth Rate (SGR) and Feed Conversion Ratio (FCR) were determined. Temperature, pH, conductivity and total dissolved
solids were measured using standard methods. Data were analyzed using descriptive statistics and ANOVA at P=0.05. Result
revealed that all male tilapia had significant weight gain (p<0.05) (5.93 ± 0.13 g) compared to the mixed sexes (2.19 ± 0.09 g).
However, breeding activity was not noticed within the mixed sex tilapia population after a culture period of six months. Hence, poor
performance could not be directly linked to spawning activity. The value of temperature, pH, conductivity and total dissolved solids
were closely related and were within recommended range for the culture of tropical fishes. It was therefore hypothesized that 17
α-methyltestosterone besides achieving masculation, may have growth promoting characteristic. The detail mechanism responsible
for this better performance could be the focus of future research.
Keywords
Oreochromis niloticus
; Water quality; Growth Performance; 17 α-methyltestosterone
1 Introduction
Aquaculture industry in the last five decades has grown at an unprecedented rate with an average growth of 3.2
percent per year (FAO, 2012). This growth has been stimulated by the increased demand for fish and fishery
products as global awareness of fish as healthy food increased and the production from capture fisheries becomes
almost static (Ataguba and Okomoda, 2011). Aquaculture has traditionally played a role in ensuring food security,
and it is a very important component of rural development programs to alleviate poverty (FAO, 2006). There are
many aquaculture species and among of these important species indigenous to Africa is the Tilapia (
Oreochromis
niloticus
).
Tilapia is the common name applied to three genera of family Cichlidae (Sarotherodon, Oreochromis and Tilapia)
including about 70 species (Meyer, 2002). Tilapia is an important food fish in many tropical and sub-tropical
countries as it provides one of the most important sources of animal protein in the world (FAO, 2012). They are
considered suitable for culture because of their high tolerance to adverse environmental conditions, relatively high
growth rate, good taste, ability to efficiently convert organic and domestic wastes into high quality protein and the
ease with which they can be bred (Yi et al., 1996).
Tilapia is among the most studied groups of fish in Africa waterbodies and they are increasingly prominent in
freshwater aquaculture in many regions of the world (Admassu, 1996; Coward and Bromage, 1998). Hence, they
have become one of the most commercially important groups of fish sold around the world (Coward and Bromage,
1998).
The culture of tilapia is still beset with problems of their prolific breeding habit which subsequently lead to their
stunted growth. Tilapia starts breeding early enough when they are about 8 cm in size. Within a few months of
culture, a tilapia pond becomes full with small fish, resulting to slower growth as a result of overpopulation.
