scholarly journals Effect of feed pellet size and tank water level on growth performance in juvenile pikeperch, Sander lucioperca (L.), reared in a recirculating system

2021 ◽  
Vol 29 (2) ◽  
pp. 88-99
Author(s):  
Michał Kozłowski ◽  
Iwona Piotrowska ◽  
Bożena Szczepkowska

Abstract Three 28-day experiments were performed to assess the impact of two sinking feed pellet sizes (0.5–1.0 and 0.9–1.6 mm for experiment I, 0.9–1.6 and 1.3–2.0 mm for experiment II, and 1.3–2.0 and 1.6–2.4 mm for experiment III) and two tank water levels (0.50 and 0.65 m) on the growth performance of juvenile pikeperch of different mean initial body weights in experiment I, II, III respectively (1.1 ± 0.1 g, 5.1 ± 0.2 g, 16.6 ± 0.5 g) at different ages (67, 102, and 137 days post hatch). Two-factor analysis of variance showed that the growth of pikeperch was positively correlated with feed pellet size in experiment I, both feed pellet size and water level in experiment II, and water level in experiment III. The feed pellet sizes of 0.9–1.6 and 1.3–2.0 mm at body weights of 1.1 g and 5.1 g, respectively, are recommended to promote more efficient pikeperch growth rates. In the case of pikeperch with a body weight of 16.6 g, the feed pellet size was less important than the tank water level.

2011 ◽  
Vol 56 (No. 3) ◽  
pp. 136-149 ◽  
Author(s):  
A. Kowalska ◽  
Z. Zakęś ◽  
B. Jankowska ◽  
K. Demska-Zakęś

In this study, 16-month-old pikeperch, Sander lucioperca, (initial body weight 280 g) were fed three diets with different lipid levels with the aim of determining the impact on the growth performance, hepatic and intestinal histological structure, chemical composition, and slaughter yield of this species. The fish were fed isoproteinaceous feeds (450 g protein/kg feed) containing 60 g lipids/kg feed (group F6), 100 g lipids/kg feed (group F10) and 180 g lipids/kg feed (group F18). No significant differences were noted among the treatment groups in body weight gain and in the feeding coefficients of experimental feeds (P > 0. 05). In the group of fish administered the diet with the lowest lipid content (group F6), the share of skinned fillet in the whole body weight was the highest (48% vs. 43% in group F18) (P < 0.05). No significant differences among groups were confirmed in the relative values of the viscera weight (4.8–5.8%) (P > 0.05). The highest values of the size of hepatocytes and their nuclei, intestinal cells, supranuclear vacuoles of enterocytes, and the degree of vacuolization in hepatocytes were determined in group F18 (P < 0.05), indicating histopathological changes. The highest body and viscera lipid contents were noted in individuals from group F18 (P < 0.05). The high lipid content in the viscera of fish from this group was linked to the significantly lowest content of protein and ash. The levels of lipids, protein, and ash were similar (P > 0.05) in the pikeperch fillets from the three feeding treatments. The levels of n-6 polyunsaturated fatty acids (n-6 PUFA) in the whole fish body, in the viscera and fillets (P < 0.05) were the significantly highest in group F18. Significant differences in n-3 polyunsaturated fatty acids (n-3 PUFA) among the groups were confirmed in the whole fish body and viscera (P < 0.05), while the values in the fillets were similar (P > 0.05). The n–3/n–6 index for the fish fillets ranged from 2.4 (group F18) to 4.7 (group F6) (P < 0.05). The levels of n-3 highly unsaturated fatty acids (n-3 HUFA), arachidonic acid (ARA) and docosahexaenoic acid (DHA) in the fillets of fish from the three dietary treatments were similar (P > 0.05). The fillets of fish from group F6, however, had the lowest levels of linolenic and linoleic acid (ALA and LA) and the highest levels of eicosapentaenoic acid (EPA) (P < 0.05).


2019 ◽  
Vol 3 (2) ◽  
Author(s):  
T. R. Krause ◽  
E. R. Moore ◽  
J. Duggin ◽  
J. R. Segers ◽  
T. D. Pringle

ObjectivesProfitability in the beef industry has narrow margins regulated by revenue from output traits like growth and carcass merit, but profitability is also largely impacted by input expenses like feed costs. Selecting for improvements in feed efficiency during the finishing phase, one of the most feed intensive segments of the industry, can help to mitigate those input costs. This study compared growth performance, feed efficiency, body composition, and carcass characteristics in Angus steers (n = 321) from bulls divergently selected for feed efficiency and marbling.Materials and MethodsAngus sires were selected based on high (10th percentile or better) and low (85th percentile or worse) residual average daily gain (RADG) EPD as well as high (fifth percentile or better) and average (near 50th percentile) marbling (MARB) EPD. These criteria resulted in a 2 × 2 factorial design with four breeding lines: high RADG/high MARB, high RADG/average MARB, low RADG/high MARB, low RADG/average MARB. Data were analyzed using MIXED procedures of SAS with RADG and MARB as main effects. Significance was set at α = 0.05. Generation was also analyzed, where generation one (GEN1) steers were from a selected sire while generation two (GEN2) steers were from a selected sire and a selected dam.ResultsUltrasound and carcass data revealed no differences (P ≥ 0.12) in 12th rib backfat thickness from weaning through slaughter for the RADG EPD groups. Yield grade and dressing percent did not differ (P ≥ 0.56) across RADG or MARB groups. At the beginning and end of the feeding trial, the high RADG (P ≤ 0.02) group had larger ultrasound ribeye area (REA) than the low RADG group. Carcass REA tended (P = 0.08) to be larger in the high versus low RADG steers. During the feedlot trial and through slaughter, body weight was heavier (P ≤ 0.006) for the high versus low RADG steers but did not differ (P ≥ 0.44) across MARB EPD. Feed efficiency measures did not differ (P ≥ 0.32) across RADG or MARB groups apart from the tendency (P = 0.08) for residual feed intake to be lower in the high versus low RADG steers. Marbling scores differed (P ≤ 0.04) across RADG and MARB groups with the low RADG steers and the high MARB steers having improved marbling. The quality grade distribution across MARB EPD revealed that the average MARB steers graded 73% Choice and 25% Prime while the high MARB steers graded 56% and 42%, respectively. Slice shear force did not differ (P ≥ 0.32) across RADG or MARB EPD. Body weights tended (P = 0.06) to be heavier at the start of the feeding trial for GEN1 versus GEN2 steers. Total gain, average daily gain, and feed to gain (F:G) differed by generation (P ≤ 0.007) with increased rates of gain and reduced F:G in the GEN2 versus GEN1 steers. Body weights did not differ (P = 0.72) across GEN at the end of the feeding trial. Backfat thickness at the start and end of the feedlot phase was less (P ≤ 0.03) and marbling score was improved (P = 0.02) in the GEN2 versus GEN1 steers, respectively.ConclusionThese results suggest that selection using RADG EPD has negligible impacts on meat quality; and that progress in selection for efficiency can be achieved while advancing carcass quality and value. Furthermore, continued divergent selection for feed efficiency and marbling has the potential to improve feed efficiency through advancements in the rate of gain, while enhancing carcass merit through marbling.


2021 ◽  
Vol 52 (6) ◽  
pp. 1401-1407
Author(s):  
S. Atroun ◽  
C. Aissaoui ◽  
S. Smeti ◽  
N. Atti

The objective of this work was to study the lamb’s growth, the carcass yield and composition and the importance of main organs of Berber lambs slaughtered at 4 or 6 months. The study concerned 40 lambs reared under motherhood. Lambs of the first group were slaughtered at the age of 4 months (4M) and the second at 6 months (6M). Slaughter body weights (BW), hot and cold carcass weights and organs were recorded. The carcass was cut out and dissected. The average BW at birth was 4.14 + 0.506 kg while the BW at slaughter was 22.86 kg + 3.40 and 31.51 + 3.50 kg for 4M and 6M groups, respectively. The average daily gain were 172 and 164g for 4M and 6M groups, respectively. Therefore, during 2months the lambs of 6M group gained 8.67 kg in BW. The carcasses were heavier for 6M than 4M. The carcass commercial yields were 42% and 45% for 4M and 6M groups, respectively, resulting in 4.1 kg gain of meat during 2 months. The tissular (muscle, fat and bone) and the regional (leg, shoulder …) carcass composition did not differ among groups. All organs were heavier for 6M than 4M; however, their proportion in the empty body weight were variables. The BWand carcass gain at six months are encouraging to prolong the lamb’s slaughter age without carcass composition difference given the similar fat proportion in the carcass of both groups.


Atmosphere ◽  
2022 ◽  
Vol 13 (1) ◽  
pp. 95
Author(s):  
Phil J. Watson

This paper provides an Extreme Value Analysis (EVA) of the hourly water level record at Fort Denison dating back to 1915 to understand the statistical likelihood of the combination of high predicted tides and the more dynamic influences that can drive ocean water levels higher at the coast. The analysis is based on the Peaks-Over-Threshold (POT) method using a fitted Generalised Pareto Distribution (GPD) function to estimate extreme hourly heights above mean sea level. The analysis highlights the impact of the 1974 East Coast Low event and rarity of the associated measured water level above mean sea level at Sydney, with an estimated return period exceeding 1000 years. Extreme hourly predictions are integrated with future projections of sea level rise to provide estimates of relevant still water levels at 2050, 2070 and 2100 for a range of return periods (1 to 1000 years) for use in coastal zone management, design, and sea level rise adaptation planning along the NSW coastline. The analytical procedures described provide a step-by-step guide for practitioners on how to develop similar baseline information from any long tide gauge record and the associated limitations and key sensitivities that must be understood and appreciated in applying EVA.


2020 ◽  
Vol 12 (20) ◽  
pp. 3419
Author(s):  
Tomás Fernández-Montblanc ◽  
Jesús Gómez-Enri ◽  
Paolo Ciavola

The knowledge of extreme total water levels (ETWLs) and the derived impact, coastal flooding and erosion, is crucial to face the present and future challenges exacerbated in European densely populated coastal areas. Based on 24 years (1993–2016) of multimission radar altimetry, this paper investigates the contribution of each water level component: tide, surge and annual cycle of monthly mean sea level (MMSL) to the ETWLs. It focuses on the contribution of the annual variation of MMSL in the coastal flooding extreme events registered in a European database. In microtidal areas (Black, Baltic and Mediterranean Sea), the MMSL contribution is mostly larger than tide, and it can be at the same order of magnitude of the surge. In meso and macrotidal areas, the MMSL contribution is <20% of the total water level, but larger (>30%) in the North Sea. No correlation was observed between the average annual cycle of monthly mean sea level (AMMSL) and coastal flooding extreme events (CFEEs) along the European coastal line. Positive correlations of the component variance of MMSL with the relative frequency of CFEEs extend to the Central Mediterranean (r = 0.59), North Sea (r = 0.60) and Baltic Sea (r = 0.75). In the case of positive MMSL anomalies, the correlation expands to the Bay of Biscay and northern North Atlantic (at >90% of statistical significance). The understanding of the spatial and temporal patterns of a combination of all the components of the ETWLs shall improve the preparedness and coastal adaptation measures to reduce the impact of coastal flooding.


Author(s):  
Shuo Yang ◽  
Raymond K. Yee

As a common phenomenon in liquid motions, sloshing usually happens in a partially filled liquid tank of moving vehicle or structure. The objectives of this paper are to study sloshing behavior in rigid tank and deformable tank, and to develop a better performance baffle design in the tank under seismic excitations. The tank is surged with a sinusoidal oscillation about horizontal x-direction. The hydro-elasticity effect of sloshing pressure on the tank wall was taken into consideration due to the fluid-structure interaction between impact pressures and tank structures. ABAQUS finite element program using Coupled Eulerian-Lagrangian (CEL) technique was employed to simulate fluid sloshing. The sloshing phenomenon was studied in rigid tank and deformable tank models with three different water levels, and the effect of wall thickness of the deformable tank on sloshing behavior was discussed. One way to minimize the effect of sloshing in a tank, baffles are used and installed in the middle of the tank, and then various heights and material types of baffle were evaluated. The simulation results show that higher water level case creates greater pressure impact on the tank wall than lower water level case, and the elasticity of the tank structure would reduce the impact pressure of the wall. For the simulation tank model with size of 1m (H) × 1m (W) × 0.2m (D), better performance baffle was found to be the one with the height of 0.35m and was made of acrylic material. Moreover, the conclusion of this study can be extrapolated to other dimensions of the model based on similarity theory. This paper also can serve as an aid in further studying sloshing phenomenon. The findings of this study can be applied to restrain or minimize sloshing motions inside a tank.


Water ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1484 ◽  
Author(s):  
Jinyan Sun ◽  
Lei Ding ◽  
Jiaze Li ◽  
Haiming Qian ◽  
Mengting Huang ◽  
...  

The spatial extent and area of river islands are always changing due to the impact of hydrodynamic conditions, sediment supply and human activities. A catastrophic flood disaster was driven by sustained and heavy rainfall around the middle and lower Yangtze River in 18 June to 21 July 2016. The flood resulted in the most serious social-economic loss since 1954 and caused a larger-scale inundation for a short time. It is essential to continuously monitor the dynamics changes of river islands because this can avoid frequent field measurements in river islands before and after flood disasters, which are helpful for flood warning. This paper focuses on the temporal change of three river islands called Fenghuangzhou, Changshazhou, and one uninhabited island in the Yangtze River in 2016. In this study, GF-1 (GaoFen-1) WFV (wide field view) data was used for our study owing to its fine spatial and temporal resolution. A simple NDWI (Normalized Difference Water Index) method was used for the river island mapping. Human checking was then performed to ensure mapping accuracy. We estimated the relationship between the area of river islands and measured water levels using four models. Furthermore, we mapped the spatial pattern of inundation risk of river islands. The results indicate a good ability of the GF-1 WFV data with a 16-m spatial resolution to characterize the variation of river islands and to study the association between flood disaster and river islands. A significantly negative but nonlinear relationship between the water level and the area of the river island was observed. We also found that the cubic function fits best among three models (R2 > 0.8, P < 0.001). The maximum of the inundated area at the river island appeared in the rainy season on 8 July 2016 and the minimum occurred in the dry season on 28 December 2016, which is consistent with the water level measured by the hydrological station. Our results derived from GF-1 data can provide a useful reference for decision-making of flood warning, disaster assessment, and post-disaster reconstruction.


1998 ◽  
Vol 25 (5) ◽  
pp. 864-879 ◽  
Author(s):  
Jean Morin ◽  
Michel Leclerc

Lake Saint-François is a relatively shallow fluvial lake of the St. Lawrence River with numerous deep channels. This complex system has been considerably altered from its pristine state 150 years ago. Currently, the water level is stabilized and the flow is regulated; important areas have been dredged and the major part of its outflow is diverted through the Beauharnois canal. The evolution of water levels shows a trend towards stabilization as required for ship traffic in the St. Lawrence Seaway and for hydropower production. With the construction of the Moses-Saunders dam in 1960, the flow of the river could be regulated; changes occur in the seasonal pattern of the flow. Ancient stage-discharge relationships were recreated to describe the impact of the 1849 damming and of the present level stabilization. Stabilization of the water level has favored the growth of submerged plants. Manning's friction coefficient was used to show that plant biomass has doubled since 1920; the onset of biomass increases corresponds to a water level stabilization event. The distribution of wetlands in the Lake Saint-François area was drastically modified by the water level rise caused by the 1849 damming. New wetlands were created and pre-1849 wetlands, located on what are currently shoals in the central part of the lake, have totally disappeared.Key words: Lake Saint-François, St. Lawrence River, impact of civil works, flow discharge regulation, water level regulation, wetland flooding cycle, submerged macrophyte, ecosystem reaction, civil work history.


2017 ◽  
Vol 37 (3) ◽  
pp. 275-284 ◽  
Author(s):  
RS Ferreira ◽  
L de Souza Morelini ◽  
EMC de Azeredo ◽  
ECS Vieira ◽  
EB Ferreira ◽  
...  

Cereal-based diets formulated as semi-purified diets can provide flexibility for researchers, enabling open controlled formulas, besides being cheaper than purified diets. Seeking to widen the researchers’ options in their experimental design developments, we aimed at assaying the chemical score, growth performance and protein utilization of nine semi-purified experimental chows. These diets were formulated at 17.8%, 12% and 8% protein contents, using three variations of ingredients for each one, as follows: casein (C), casein+soybean meal (C+S, 1:1 w/w protein) and casein+soybean meal+corn gluten meal (C+S+G, 1:1:1 w/w protein), without cysteine supplementation and setting casein 17.8% (AIN-93G) as reference diet. The diets C and C+S (17.8%) had the Cys as the limiting amino acid once the addition of gluten turns the Lys as second limiting. All diets had the potential for promoting growth with body mass gain, feed conversion ratio (FCR; chow consumed per body weight gain, average 3.12) and feed efficiency ratio (FER; body weight gain per chow consumed, average 0.3), except for C+S+G 8% (FCR = 6 g; FER = 0.13). These variations were mainly due to the protein amounts independently from the protein ingredient used and could characterize the C+S+G 8% as unable to support growth. For the other parameters (digestibility, net protein ratio, net protein utilization and protein efficiency ratio), there were no relevant differences between the diets. We can conclude that 17.8%, 12% and 8% chows (C and C+S) allowed a proper combination of ingredients from the point of view of palatability, nutrient availability/utilization, metabolic processes, growth performance and feed utilization parameters.


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