Original Research Article
Year: 2020 | Month: July | Volume: 7 | Issue: 7 | Pages: 376-383
Optimum Dietary Crude Protein and Digestible Energy Requirements for fingerlings of Hybrid Clariid catfish Clarias gariepinus♀ X Heterobranchus bidorsalis♂ in the Tropics
B.S. Aliu, J.M. Olomu
Department of Fisheries, University of Benin, Benin-City, Nigeria.
Corresponding Author: B.S. Aliu
ABSTRACT
This study was carried out to determine the optimum dietary crude protein and digestible energy requirements for thecross Clarias gariepinus♀ X Heterobranchus bidorsalis♂ fingerlings. The general objective of the study was to determine the optimum protein and digestible energy levels for the Clariid catfish fingerlings, cross Clarias gariepinus♀ X Heterobranchus bidorsalis♂, using locally sourced feed inputs. Clarias gariepinus♀ X Heterobranchus bidorsalis♂ fingerlings were reared from hatchlings to five weeks old. Sixteen practical diets were formulated and used in the feeding trials. The diets were made up of four digestible energy levels (2400, 2600, 2800 and 3000Kcal/Kg), each at four crude proteins levels (25, 30, 35 and 40%) and were fed to the fingerlings for 70days in three replicates for each treatment. Weekly data were collected based on weight gain and feed consumption. Feed and fish carcasses were analyzed for proximate composition of the fingerlings. All data collected were subjected to two-way analysis of variance (ANOVA) test at 5% probability level. The result showed that weight gain increased with increase in the dietary protein levels at all energy levels used. The increases were significant in all except that between 35% crude protein and 40% crude protein at DE of 2600Kcal/kg diet. The highest weight gain was obtained in fish fed diet containing 40% crude protein and DE 2600Kcal/kg diet. These values obtained were not significantly different (P>0.05) from those obtained in fish fed diet containing 35% crude protein and DE of 2600Kcal/kg. Feed intake at DE levels of 2400 and 2600 Kcal/kg diets were similar and significantly higher (P<0.05) than feed intake at 2800 and 3000Kcal/kg. Generally, beyond 2600Kcal/kg diets, feed intake reduced significantly. Specifically, feed intake reduced when the DE level was increased from 2400 to 2600Kcal/kg at crude protein levels of 25 and 30% but increased at crude protein levels of 35 and 40%.The FCR values were not significantly affected by treatments (P>0.05). However, it is only the FCR obtained in the diets containing 25% crude protein and DE of 2400kcal/kg that was significantly different from all the others. The lowest FCR (0.84) was obtained in fish fed diet containing 25% crude protein and DE of 3000kcal/kg followed by that (1.14) of 35% crude protein and DE of 2600kcal/kg diet. At each protein level, the FCR decreased with increase in DE levels, although not significantly. At DE of 2400, 2600 and 2800kcal/kg, the FCR reduced with increase in the crude protein level up to 35%.
Keywords: Clariid catfish, Clarias gariepinus, fingerlings, optimum energy, protein levels, fish diet.
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