scholarly journals Growth of Fry Fish of 4 Species of Family Mugilidae in Experimental Recirculation Water System

Author(s):  
George Nick Hotos ◽  
Despina Avramidou

The collected in nature fry of Mugil cephalus, Liza aurata, L. ramada and Chelon labrosus that arrive in massive schools at the coastline of Greece were reared in small aquaria (50 L) of a recirculation system from the size of about 3.0 cm TL (50 fish per aquarium), using brackish (15 ppt) water and artificial high protein food. It was found that for a period of 80 days, growth performance was high at 23 oC, reaching values for weight increase between 592 (M. cephalus) and 2281 % (L. aurata). Food Conversion Ratio (FCR) was best (1.04) for L. aurata and worst (2.04) for M. cephalus. All species responded well as exhibited by an increase in their Condition Factor (CF) and mortality was almost absent.

2016 ◽  
Vol 5 (4) ◽  
pp. 13 ◽  
Author(s):  
Daud Kassam ◽  
Marcus Sangazi

<p>Most fish farmers in Malawi culture unimproved fish strains whose growth is slow and mature while still small. Four strains of <em>Oreochromis</em>, namely; selectively-bred/improved <em>O. shiranus</em> (F<sub>8</sub>), two reciprocal F<sub>1</sub> <em>Oreochromis</em> hybrids, and <em>O. karongae</em> as a control (mean weight 2.5 ± 0.7 g) were stocked at a density of 5fish/m<sup>2 </sup>in 9m<sup>2 </sup>hapas replicated three times, and cultured for 90 days at Bunda Fish Farm. Fish were fed twice a day with feed formulated using maize bran and soybean containing 30% crude protein throughout the experimental period. The final mean weights were significantly different (p&lt;0.05) across the treatments whereby; hybrid <em>O. shiranus</em> (male) X <em>O. karongae</em> (female) was 12.09g, hybrid <em>O. shiranus</em> (female) X <em>O. karongae</em> (male) was 9.72g, improved <em>O. shiranus</em> (F<sub>8</sub>) registered 9.23g, and <em>O. karongae</em> was the least with 9.00g. Apparent food conversion ratio was also statistically different (p&lt;0.05) across the treatments whereby; <em>O. karongae</em> was 3.63, hybrid <em>O. shiranus</em> (female) X <em>O. karongae</em> (male) was 3.25, improved <em>O. shiranus</em> (F<sub>8</sub>) was 3.16 and hybrid <em>O. shiranus</em> (male) X <em>O. karongae</em> (female) was lowest with 2.26. There were no significant differences on the water quality parameters across the treatments throughout the experimental period and were within the required ranges for growth and survival of tilapias fish species. The results suggest that <em>Oreochromis</em> hybrids may be suitable candidates for aquaculture in terms of production as they performed better than the improved <em>O. shiranus</em> and the control <em>O. karongae</em>.</p>


2004 ◽  
Vol 61 (6) ◽  
pp. 983-991 ◽  
Author(s):  
Björn Björnsson ◽  
Maria Álvaro Dongala Dombaxe

Abstract Nephrops was found to be of low quality as food for cod. In a laboratory experiment the mean specific growth rate of 1 kg cod was 0.184 and 0.415% d−1 when fed to satiation on Nephrops and capelin, respectively. This large difference in growth rate resulted not only from less intake of Nephrops (1.19 kg cod−1) than capelin (1.55 kg cod−1) but also because more Nephrops (4.6 kg) than capelin (2.2 kg) were required to produce each kilogramme of cod. Higher food conversion ratio was consistent with lower fat content of Nephrops (1.3%) than capelin (9.2%) but the exoskeleton also reduced the digestion rate of Nephrops. In the groups where Nephrops and capelin of equal mean weight were offered simultaneously, 40% of the diet consisted of Nephrops during the first week and 10% during the final seven weeks of the experiment. At the end of the experiment, condition factor, liver index, and gonadosomatic index were significantly lower for cod fed on Nephrops (0.967, 5.7, 7.1, respectively) than for those fed on capelin (1.086, 15.8, 11.2, respectively). These results suggests that predation by cod on Nephrops might be reduced by regular release of capelin or other similar food in the distributional areas of Nephrops.


1982 ◽  
Vol 35 (2) ◽  
pp. 177-184 ◽  
Author(s):  
R. G. Campbell ◽  
R. H. King

ABSTRACT1. Three isocaloric diets containing 170, 210 or 231 g crude protein per kg were given at two levels, and offered ad libitum to entire and castrated male pigs growing from 20 to 70 kg live weight.2. Between 20 and 45 kg, growth rate improved with each increase in level of feeding (P < 005) and, on the ad libitum treatment the food intake and growth performance of both entire and castrated pigs were similar. On the restricted feeding treatments the growth performance of entire, but not of castrated pigs, improved when dietary protein was raised from 170 to 210g/kg (P < 005).3. During the live-weight periods 45 to 70 and 20 to 70kg, raising food intake improved growth rate (P < 005) but increased the food conversion ratio and carcass fat measurements at 70 kg (P < 0·05). However, food conversion ratio and the majority of carcass characteristics of entire pigs fed ad libitum were equivalent to those of castrated pigs fed at the lowest level.4. Dietary protein level had no significant effect on growth performance from 20 to 70 kg or on carcass fat measurements at the latter weight. However, each increase in dietary protein in the live-weight period 45 to 70 kg depressed the performance of castrated pigs (P < 0·05) while that of entire pigs was reduced when the protein level of the diet was raised from 210 to 231 g/kg.


Author(s):  
P.A. Opute ◽  
I.P. Oboh

Clarias gariepinus juveniles of average weight, 17.57±1.95 g and an average length of 14.26±0.39 cm were exposed to environmentally relevant concentrations of 0 (control), 2.5, 25, 250, and 500 µg L-1 atrazine in a quality-controlled 28-day bioassay. Growth performance was assessed bi-weekly and fish samples were taken from different tanks to determine the relative growth rate, specific growth rate, feed conversion ratio, condition factor and behaviour. At the end of two weeks of exposure, the relative growth rate and the specific growth rate among exposed fish groups was found to reduce significantly (p<0.05) compared to the control, an indication of poor growth performance. The average specific growth rates (SGR) of control fish is 3.86±0.02 %/w at the end of the exposure duration while recording -0.64±0.09 in the 500 µg L-1 group. Feed conversion ratio increased significantly from control to the group with highest atrazine concentration. Condition factor (K) of fish among treatment groups showed significant decrease in values with increasing concentration of atrazine in a dose-dependent pattern. Atrazine exposure resulted in behavioural anomalies including erratic swimming, clinging to the water surface, loss of equilibrium, lethargy, and discolouration. The behavioural responses were found to be concentration-dependent. The length-weight relationships for both control and atrazine exposed fish exhibited positive allometric growth and significant relationships as depicted by the value of R2 (coefficient of determination) except in the fish group exposed to 500 µg L-1 atrazine which exhibited negative allometric growth. Findings from this study indicate interference with normal behaviour and growth performance of C. gariepinus juveniles with ecological implications in water bodies exposed to atrazine even at reduced concentrations.


2005 ◽  
Vol 6 (1) ◽  
pp. 99 ◽  
Author(s):  
P. ANGELIDIS ◽  
I. POURNARA ◽  
G. PHOTIS

On a commercial eel farm, which uses a recirculation system, 400,000 glass eels were farmed for a period of 328 days at 20o – 23o C. The physicochemical parameters of the farm water were kept at normal conditions during the experiment. The NO 2 was kept between 1.0 and 3.0 mg/l. By the end of the experiment, 4,582 kg of fish feed were consumed and 2,939 kg of eels were produced (177,523 eels with mean final individual body weight of 16.6g and mean food conversion ratio of 1.625). The glass eels showed a high variability in their capacity to grow.


2002 ◽  
Vol 74 (3) ◽  
pp. 493-502 ◽  
Author(s):  
J. H. Guy ◽  
P. Rowlinson ◽  
J. P. Chadwick ◽  
M. Ellis

AbstractA trial was conducted to compare the growth performance and carcass characteristics of 720 growing pigs housed in one of three different finishing systems: outdoor paddocks, straw yards and fully slatted pens. Two genotypes were used: ‘indoor’ (progeny of Large White ✕ Landrace sows mated to Large White boars) or ‘outdoor’ (progeny of part-Duroc or part-Meishan sows, mated to Large White boars). Groups of 20 pigs were reared from an average of 30 to 80 kg live weight and given ad libitum access to a commercial specification diet. The outdoor genotypes had significantly lower average daily gain than the indoor genotype (682, 673 and 719 g respectively for part-Duroc, part-Meishan and indoor-type pigs, P 0·01). Part-Meishan genotypes had significantly higher backfat levels than the indoor genotype (P 0·05), with an intermediate value for part-Duroc pigs (22·6, 21·1 and 21·8 mm respectively). Values for food conversion ratio were significantly higher for combined outdoor genotype groups when compared with the indoor genotype (2·76 v. jt>2·62, P 0·05). Average daily gains of pigs in straw yards and outdoor paddocks were significantly higher than for those in fully slatted pens (736 and 675 v. 627 g, P 0·01 respectively). Food conversion ratio was similar for pigs in outdoor paddocks and fully slatted pens, but significantly lower for those in straw yards (2·77 and 2·75 v. 2·55, P 0·01 respectively). Backfat depth (P1 + P3mm) was significantly greater for animals finished in straw yards compared to those in outdoor paddocks (22·2 v. 20·6 mm, P 0·05) and intermediate for those finished in fully slatted pens (21·5 mm). Interaction between finishing system and genotype did not occur to any major degree, hence it appears unnecessary to specify a particular genotype for a particular finishing system. It was concluded that pigs of the outdoor genotype had a lower growth performance compared with the indoor genotype. Finishing systems however may have been confounded by other factors so that no clear recommendations can be made as to the optimum finishing system.


Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1705
Author(s):  
Shih-Chieh Liao ◽  
Pei-Xuan Lu ◽  
Shih-Yi Shen ◽  
Chih-Chang Hsiao ◽  
Ching-Yi Lien ◽  
...  

Footpad dermatitis (FPD) is a major foot disease in modern poultry production, and it affects both poultry health and animal welfare. It refers to inflammation and necrotizing lesions on the plantar surface of the footpads and toes. We investigated the effects of providing a swimming pool and different floor types on growth performance and FPD score in indoor-reared White Roman geese. Forty-eight male and 48 female White Roman geese were randomly allocated to pens with or without a swimming pool and with either mud or perforated plastic floor and reared from 15 to 84 days of age. Growth performance measurements included feed intake (FI), weight gain (WG), and feed conversion ratio (FCR). FI, WG, and FCR were significantly decreased at various growth periods in geese provided with a pool. Lower WG and bodyweight for the perforated plastic floor group were found at 15–28 and 28 days of age, respectively. The geese reared on the perforated plastic floors without a pool had higher FPD scores at 70 and 84 days of age than those with other rearing conditions. A higher incidence of FPD score 1 was observed in geese raised without a pool. In conclusion, providing a pool can improve footpad health in indoor-reared White Roman geese but may not benefit growth performance.


2020 ◽  
Vol 23 (1) ◽  
pp. 44-54
Author(s):  
Nadezhda Palova ◽  
Jivko Nakev ◽  
Teodora Popova ◽  
Maya Ignatova

Abstract(An experiment with two groups of East Balkan pigs – castrated males (n=10) and females (n=10), was carried out to study the growth performance and fattening abilities of the animals from the weaning until slaughter. The pigs were included in the trial at 60 day age. The average live weight of the castrated males was 8. 65±1.08 kg and for the females, 8.5±0.62 kg.The pigs were reared using traditional technology, grazing on natural pastures in the Strandzha mountain, Bulgaria. In autumn, acorns were naturally present in their diet. According to the category, the animals additionally received ground organic feed (50% barley and 50% wheat). The trial lasted 304 days (from February to November, 2019). During this period the final live weight of the male castrated pigs reached 88.00 kg while that of the females was 84.4 kg. The difference, however, was not significant. Furthermore, no significant differences in the growth performance characteristics that could be attributed to the sex of the animals were observed. The average daily gain of both sexes tended to be lower in summer and higher in autumn. The feed conversion ratio was higher in summer. The animals showed high average daily weight gain at pasture when their live weight was over 50 kg.


2021 ◽  
Vol 44 (3) ◽  
pp. 135-139
Author(s):  
I. O. Suleiman ◽  
G.N. Akpa ◽  
P. I. Bolorunduro

Fish found in natural tropical and sub-tropical water system experience frequent growth fluctuations. The study was conducted to determine the length-weight relationship and condition factor of Clariid species (Clarias gariepinus, Heterobranchus longifilis and Synodontis clarias) in Kano state of Nigeria. About 177 fish samples were collected from six rivers (Thomas, Ghari, Tiga, Duddurun-Gaya, Karaye and Bagwai) across the length and breadth of Kano state. Body weight (BW=248.48g), total length (TL=32.74cm) and standard length (SL=26.16cm) were determined. The length-weight relationship and condition factors were also determined. The condition factors showed varying degree of well-being of fish sampled from their habitat, and ranged from K = 0.37 to 0.89. The equation for the lengthweight relationship for the three strains is: C. gariepinus = -329.86+17.56TL, H. longifilis = -241.49+14.28TL and C. clarias = -428.51+22.72TL. Body weight and length had positive and significant relationship (r = 0.73 TL; r = 0.75 SL).


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