scholarly journals Effect of temperature rise on growth performance, feed intake, feed conversion ratio and sex ratio of the Nile Tilapia, Oreochromis niloticus

2021 ◽  
Vol 25 (3) ◽  
pp. 159-169
Author(s):  
Elsayed A. Khallaf et al.
Keyword(s):  
Sex Ratio ◽  
Temperature Rise ◽  
Feed Intake ◽  
Oreochromis Niloticus ◽  
Nile Tilapia ◽  
Conversion Ratio ◽  
Feed Conversion Ratio ◽  
Effect Of Temperature ◽  
Feed Conversion ◽  
Nile Tilapia Oreochromis Niloticus

scholarly journals The Effects of Feed Restriction and Isolated or Group Rearing on the Measurement of Individual Feed Intake and Estimation of Feed Conversion Ratio in Juvenile Nile Tilapia (Oreochromis niloticus) for Selective Breeding Purposes

2021 ◽  
Vol 11 ◽  
Author(s):  
Charles Rodde ◽  
Marc Vandeputte ◽  
Trong Quoc Trinh ◽  
Vincent Douchet ◽  
Marc Canonne ◽  
...  
Keyword(s):  
Feed Intake ◽  
Oreochromis Niloticus ◽  
Feed Efficiency ◽  
Nile Tilapia ◽  
Selective Breeding ◽  
Conversion Ratio ◽  
Feed Conversion Ratio ◽  
Feed Conversion ◽  
Breeding Programs ◽  
The Gift

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.

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
Keyword(s):  
Oreochromis Niloticus ◽  
Nile Tilapia ◽  
Compensatory Growth ◽  
Conversion Ratio ◽  
Feed Conversion Ratio ◽  
Control Group ◽  
Average Weight ◽  
Feed Conversion ◽  
Nile Tilapia Oreochromis Niloticus ◽  
Size Heterogeneity

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.

Daily methane emissions and emission intensity of grazing beef cattle genetically divergent for residual feed intake

2017 ◽  
Vol 57 (4) ◽  
pp. 627 ◽  
Author(s):  
J. I. Velazco ◽  
R. M. Herd ◽  
D. J. Cottle ◽  
R. S. Hegarty
Keyword(s):  
Feed Intake ◽  
Emission Intensity ◽  
Dry Matter ◽  
Average Daily Gain ◽  
Residual Feed Intake ◽  
Conversion Ratio ◽  
Feed Conversion Ratio ◽  
Breeding Value ◽  
Dry Matter Intake ◽  
Feed Conversion

As daily methane production (DMP; g CH4/day) is strongly correlated with dry matter intake (DMI), the breeding of cattle that require less feed to achieve a desired rate of average daily gain (ADG) by selection for a low residual feed intake (RFI) can be expected to reduce DMP and also emission intensity (EI; g CH4/kg ADG). An experiment was conducted to compare DMP and EI of Angus cattle genetically divergent for RFI and 400-day weight (400dWT). In a 6-week grazing study, 64 yearling-age cattle (30 steers, 34 heifers) were grazed on temperate pastures, with heifers and steers grazing separate paddocks. Liveweight (LW) was monitored weekly and DMP of individual cattle was measured by a GreenFeed emission monitoring unit in each paddock. Thirty-nine of the possible 64 animals had emission data recorded for 15 or more days, and only data for these animals were analysed. For these cattle, regression against their mid-parent estimated breeding value (EBV) for post-weaning RFI (RFI-EBV) showed that a lower RFI-EBV was associated with higher LW at the start of experiment. Predicted dry matter intake (pDMI), predicted DMP (pDMP) and measured DMP (mDMP) were all negatively correlated with RFI-EBV (P < 0.05), whereas ADG, EI, predicted CH4 yield (pMY; g CH4/kg DMI) were not correlated with RFI-EBV (P > 0.1). Daily CH4 production was positively correlated with animal LW and ADG (P < 0.05). The associations between ADG and its dependent traits EI and pMY and predicted feed conversion ratio (kg pDMI/kg ADG) were strongly negative (r = –0.82, –0.57 and –0.85, P < 0.001) implying that faster daily growth by cattle was accompanied by lower EI, MY and feed conversion ratio. These results show that cattle genetically divergent for RFI do not necessarily differ in ADG, EI or pMY on pasture and that, if heavier, cattle with lower RFI-EBV can actually have higher DMP while grazing moderate quality pastures.

scholarly journals Productive performance of Nile tilapia (Oreochromis niloticus) fed at different frequencies and periods with automatic dispenser

2012 ◽  
Vol 64 (1) ◽  
pp. 192-197 ◽  
Author(s):  
R.M.R. Sousa ◽  
C.A. Agostinho ◽  
F.A. Oliveira ◽  
D. Argentim ◽  
P.K. Novelli ◽  
...  
Keyword(s):  
Oreochromis Niloticus ◽  
Nile Tilapia ◽  
Productive Performance ◽  
Feed Conversion ◽  
Feeding Frequency ◽  
Nile Tilapia Oreochromis Niloticus ◽  
Significant Difference ◽  
Final Weight ◽  
Autumn And Winter ◽  
Feed Conversion Rate

The performance of Nile tilapia (Oreochromis niloticus) raised in cages furnished with an automatic dispenser, supplied at different frequencies (once per hour and once every two hours) and periods (daytime, nighttime and both) was evaluated. Eighteen 1.0m³ cages were placed into a 2000m² pond, two meters deep with a 5% water exchange. One hundred and seventy tilapias, with initial weight of 16.0±4.9g, were dispersed into each 1m³ cage and the feed ration was adjusted every 21 days with biometry. Data was collected from March to July (autumn and winter). Significant difference to final weight (P<0.05) among treatments was observed. The increase in feeding frequency improves the productive performance of Nile tilapias in cages and permitted better management of the food. The better feed conversion rate for high feeding frequency (24 times day-1) can result in saving up to 360kg of food for each ton of fish produced, increasing the economic sustenance for tilapia culture and suggesting less environmental pollution.

scholarly journals Nitrogen and phosphorus flux from the production of Nile tilapia through the application of environmental indicators

2017 ◽  
Vol 78 (1) ◽  
pp. 25-31 ◽  
Author(s):  
J. A. S. Osti ◽  
M. A. B. Moraes ◽  
C. F. Carmo ◽  
C. T. J. Mercante
Keyword(s):  
Best Management Practices ◽  
Nile Tilapia ◽  
Management Practices ◽  
Environmental Indicators ◽  
Conversion Ratio ◽  
Feed Conversion Ratio ◽  
Phase Iii ◽  
Production Cycle ◽  
Fish Biomass ◽  
Feed Conversion

Abstract We aimed in this study utilize environmental indicators as a quantitative method to evaluate and discuss the nitrogen (TN) and phosphorus (TP) flux by a production stage grow-out (termination) of Nile tilapia (Oreochromis niloticus) in fishpond. The TN and TP load, the mass balance, the input of TN and TP via feed and the converted nutrients in fish biomass are the environmental indicators applied in this study. During the production cycle (128 days), the system exported 15,931 g TN and 4,189 g TP that were related to the amount of feed supplied (r Pearson = 0.8825 and r = 0.8523, respectively), corroborated by the feed conversion ratio (1.61:1). The indicators showed that 26% TN and 45% TP were reversed into fish biomass, 62% TN and 40% TP were retained in the fishpond, and 12% TN and 15% TP were exported via effluent. The largest contribution of nutrients generated by the system and exported via effluent was observed in phase III and IV. This result is supported by the feed conversion ratio 2.14 and 2.21:1 obtained at this phase, a fact explained by the amount of feed offered and the fish metabolism. Application of environmental indicators showed to be an efficient tool to quantify flux of TN and TP produced during the grow-out period of Nile tilapia and therefore, guide management practices more sustainable. Concerning the environmental sustainability of the activity the implementation of best management practices such as the better control of the feed amount offered would lead to a smaller loss of TN and TP to the water. Furthermore, the use of better quality feeds would allow greater nutrient assimilation efficiency.

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