scholarly journals Compensatory growth in Nile tilapia Oreochromis niloticus: feed conversion ratio, size heterogeneity, and proximal composition

2020 ◽  
Vol 48 (3) ◽  
pp. 421-428
Author(s):  
Gaspar Román Poot-López ◽  
Eucario Gasca-Leyva ◽  
Carlos González- Salas ◽  
Sergio Guillen-Hernández ◽  
Roger Domínguez-May

A feeding test was performed to evaluate compensatory growth in the Nile tilapia (Oreochromis niloticus) and to assess changes in feed conversion ratio (FCR), body condition, and carcass composition associated with the imposed feeding strategy. The experiment was carried out under two different stages, restricted (RS) and compensated (CS), with six weeks long each other. Three hundred juveniles of Nile tilapia (average weight of 16.4 ± 0.2 g) were divided into three treatments and one control. The control group was fed to apparent satiation four times a day in both stages. The RS treatments were based on 100% (RS100), 80% (RS80), and 60% (RS60) of a feeding chart, respectively. In the next six weeks, fishes from the CS treatments (CS100, CS80, and CS60) were then fed to apparent satiation four times a day. In the RS, the control group displayed the most considerable weight gained, but with a significant FCR. Nevertheless, in the CS, the previous restricted treatments (RC80 and RC100) showed a compensatory growth, with a smaller FCR than the control group. The restricted-compensated rations did not have a significant effect on the size heterogeneity; when the food is restricted, fish use to moisturize their tissue to compensate for the muscle loss until they receive more food. However, when the food restriction levels are too high, the weight gain, lipid, and protein levels do not recover as they were before. Thus, restricted (marginally) and compensatory feeding strategies provide evidence that growth rates of fishes can be regulated.

2020 ◽  
Vol 8 (1) ◽  
pp. 71
Author(s):  
Paul Mamadou Ndour ◽  
Jean Fall ◽  
Abdoulaye Loum ◽  
Saloum Jatta ◽  
Mariama Sagne ◽  
...  

This study aimed to evaluate the impact of plant-based food additives on growth performance, body composition and survival of Nile tilapia. Four isonitrogenous (25% CP) and isolipidic (13% CL) experimental diets were prepared and designated as R1, R2, R3, and R4. R1 contains (3% Cymbopogon citratus), R2 contains (3% Ocimum basilicum), R3 contains (3% Mentha spicata) and R4 (control or 0% additive). 180 Nile tilapia fry with an initial average weight of 0.2g were distributed in 12 plastic tanks (50 L/tank) at the stocking density of 15 fish per tank in an isolated system. Fish were fed with experimental diets 3 times per day (8:00 am, 1:00 pm and 5 :00 pm) for 3 months. After 90 days of experiment, the results revealed that the final average weight ranged from 2.62g to 8.00g, the absolute average weight gain (AAWG) from 2.42 to 7.8g, the feed conversion ratio (FCR) from 1.31 to 2.67 and specific growth rate (SGR) from 3.06 to 4.36%/d. The survival rate (SR) varied between 64 and 100%. Of the parameters studied such as the absolute average weight gain (AAWG), the specific growth rate (SGR), the feed conversion ratio (FCR), and the survival rate, the best were obtained by the group of fish fed with the R2 diet containing 3% Ocimum basilicum. The results of the analysis of the flesh showed that the addition of 3% O. basilicum does not modify the contents of dry matter, crude protein, and ash but slightly increased the fat content. Based on the results, the inclusion of natural plant-based food additive (3% Ocimum basilicum) in the diet of Nile tilapia improved the parameters of growth, feed efficiency, and survival.


2017 ◽  
Vol 22 (1) ◽  
pp. 10-16
Author(s):  
Suraj Babu Ghimire ◽  
Rahul Ranjan

 This study was done to explore the effect of replacing mustard oilcake by linseed oilcake in feed on the growth performance of Nile Tilapia (Oreochromis niloticus). Mustard oilcake (MOC) was replaced by linseed oil cake (LOC) at three different level 0%, 50% and 100% to prepare three different types of diets. Diets were prepared with about 18% analyzed crude protein content. Fingerlings were kept in three happa with three replications for each diet in completely randomized design (CRD). Fish of average weight 5.31 g were stocked in happa having size 1.5m×1.5m×1.2m. The experimental fish were fed 3% of their body weight per day, once in the morning for five months continuously. No significant difference (p>0.05) in final mean weight, final total weight, average daily weight gain (DWG), survival rate, extrapolated gross fish yield (GFY), extrapolated net fish yield (NFY) and apparent feed conversion ratio (AFCR) among different treatments were observed. Hence, linseed oilcake can be used as the substitute in the feed of tilapia, if it is locally available.  Journal of Institute of Science and Technology, 2017, 22 (1): 10-16 


2015 ◽  
Vol 36 (6Supl2) ◽  
pp. 4237
Author(s):  
Nadia Cristine Weinert ◽  
Julieta Volpato ◽  
Ádson Costa ◽  
Rozyanne Rosa Antunes ◽  
Aldo Camargo de Oliveira ◽  
...  

<p>Clinical hematology facilitates the diagnosis of disease and can act as a prognostic indicator of pathological conditions in fish. The aim of the present study was to evaluate hematological parameters of Nile tilapia (<em>Oreochromis niloticus</em>) subjected to different anesthetics and anticoagulants. Thirty apparently healthy fishes (average weight of 473 ± 35. 50 g and mean total length of 29. 33 ± 0. 37 cm), were selected from the local commercial fish farm in the Lages municipality (Santa Catarina, Brazil). The animals were randomly divided into three groups of 10. In two groups, anesthesia was induced with eugenol (70 mg·L- 1) (EG) and Benzocaine hydrochloride (100 mg·L-1) (BG), respectively. Anesthesia was not administered to fish of the third group (CG/control group). Blood samples were obtained by venipuncture of the caudal vessels and placed into microtubes containing sodium heparin or Na2EDTA for further analysis. The results were analyzed by Sigma Stat for Windows, the paired t-test for significant differences between anticoagulants of the same group, and analysis of variance followed by the Tukey test for comparison of means between groups (p ? 0. 05). Most of the observed changes in the erythrogram were significantly higher for the anticoagulant heparin and benzocaine group in comparison to the control group. However, the values obtained for the leukogram were significantly higher for all groups subjected to the Na2EDTA anticoagulant, suggesting that heparin may cause cell clumping. The results suggest that the anesthetics under investigation effectively minimizes the effects of stress caused by handling and invasive procedures, and that the anticoagulant heparin causes less hemolysis in comparison to Na2EDTA for Nile tilapia. Thus, the hematological variations attributed to different anesthetic protocols and/or different anticoagulants should be considered for the species <em>Oreochromis niloticus. </em></p>


2015 ◽  
Vol 36 (6Supl2) ◽  
pp. 4237
Author(s):  
Nadia Cristine Weinert ◽  
Julieta Volpato ◽  
Ádson Costa ◽  
Rozyanne Rosa Antunes ◽  
Aldo Camargo de Oliveira ◽  
...  

Clinical hematology facilitates the diagnosis of disease and can act as a prognostic indicator of pathological conditions in fish. The aim of the present study was to evaluate hematological parameters of Nile tilapia (Oreochromis niloticus) subjected to different anesthetics and anticoagulants. Thirty apparently healthy fishes (average weight of 473 ± 35. 50 g and mean total length of 29. 33 ± 0. 37 cm), were selected from the local commercial fish farm in the Lages municipality (Santa Catarina, Brazil). The animals were randomly divided into three groups of 10. In two groups, anesthesia was induced with eugenol (70 mg·L- 1) (EG) and Benzocaine hydrochloride (100 mg·L-1) (BG), respectively. Anesthesia was not administered to fish of the third group (CG/control group). Blood samples were obtained by venipuncture of the caudal vessels and placed into microtubes containing sodium heparin or Na2EDTA for further analysis. The results were analyzed by Sigma Stat for Windows, the paired t-test for significant differences between anticoagulants of the same group, and analysis of variance followed by the Tukey test for comparison of means between groups (p ? 0. 05). Most of the observed changes in the erythrogram were significantly higher for the anticoagulant heparin and benzocaine group in comparison to the control group. However, the values obtained for the leukogram were significantly higher for all groups subjected to the Na2EDTA anticoagulant, suggesting that heparin may cause cell clumping. The results suggest that the anesthetics under investigation effectively minimizes the effects of stress caused by handling and invasive procedures, and that the anticoagulant heparin causes less hemolysis in comparison to Na2EDTA for Nile tilapia. Thus, the hematological variations attributed to different anesthetic protocols and/or different anticoagulants should be considered for the species Oreochromis niloticus.


2021 ◽  
Vol 11 ◽  
Author(s):  
Charles Rodde ◽  
Marc Vandeputte ◽  
Trong Quoc Trinh ◽  
Vincent Douchet ◽  
Marc Canonne ◽  
...  

Accurately measuring the phenotype at the individual level is critical to the success of selective breeding programs. Feed efficiency is a key sustainability trait and is typically approached through feed conversion ratio (FCR). This requires measurements of body weight gain (BWG) and feed intake (FI), the latter being technically challenging in fish. We assessed two of the principal methods for measuring feed intake in fish over consecutive days: (1) group rearing 10 fish per group and video recording the meals and (2) rearing fish individually on a restricted ration. Juvenile Nile tilapia (Oreochromis niloticus) from the Genetically Improved Farmed Tilapia (GIFT) strain and the Cirad strain were entered into the study (128 GIFT and 109 Cirad). The GIFT strain were reared over three consecutive periods of 7 days each under different feeding, recording, and rearing scenarios (i) in groups fed an optimal ration (g100) or (ii) fed a 50% restricted ration (g50) both with video records of all meals and (iii) reared in isolation and fed a 50% restrictive ration. The Cirad strain were tested similarly but only for scenarios (i) and (iii). All fish were fed twice daily with a calculated ration. Correlations showed the same trends for the GIFT and the Cirad strains. For the GIFT strain, correlations were positive and significant for BWG and FI measured in scenarios (i) and (ii), 0.49 and 0.63, respectively, and FI measured in scenarios (i) and (iii) (0.50) but not for BWG measured in scenarios (i) and (iii) (0.29, NS). The phenotypic correlation estimated for FCR between scenarios (i) and (ii) with fish fed an optimal or a 50% restricted ration was low and not significant (0.22). Feed Conversion Ratio for GIFT fish reared in groups or in isolation and fed with a restricted ration [scenarios (ii) and (iii)] were not significantly correlated either. Social interactions between fish, potentially impacting their efficiency, may explain the results. Therefore, selective breeding programs seeking to improve feed efficiency will need to carefully plan the feeding rate and the rearing system used to estimate FCR in order to optimize selection for the targeted production system.


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