scholarly journals The Effect of Slaughtering Procedures on Blood Spotting in Rainbow Trout (Oncorhynchus Mykiss)

Author(s):  
George Liviu MIHALCA ◽  
Mihaela TIŢA ◽  
Ana MIHALCA ◽  
Ovidiu TIŢA

Rainbow trout (Oncorhynchus mykiss) was submitted for various slaughter and bleeding procedures to see what effect this would have on blood drainage of the muscles. Results show that the bleeding method is of less importance, while it is the timing that is important. No significant difference in bloodspotting was observed between fish that were bled live by a gill cut or percussive killed and bled by gutting. Most of the drainage of blood in the fish muscle seems to occur within the first hours postmortem, so rigor mortis is of little importance. The visual appearance of the fillet was influenced by number and size of the bloodstains. Colour measurements with Hunter L*, a*, b* did not reveal this. We conclude that a gill cut is not necessarily to obtain bleeding, so the industry can omit this phase and go directly to gutting.

2012 ◽  
Vol 48 (No. 8) ◽  
pp. 215-220 ◽  
Author(s):  
I. Strunjak-Perovic ◽  
R. Coz-Rakovac ◽  
N. Topic Popovic

The aim of the study was to observe the influence of different ploidy levels in fish on micronucleus occur­rence. Twenty minutes after fertilization, one group of rainbow trout eggs was exposed to water temperatures of 26°C in duration of 20 minutes to induce triploidy. Second group was kept in water temperature of 10°C, which is optimal for development of rainbow trout. The frequency of micronucleated erythrocytes was determined in the peripheral circulation of rainbow trout 67 days (following absorption of the yolk – swim-up stage) and 128 days (fry stage) post fertilization. There was a significant difference (P < 0.001) between frequency of micronucleated erythrocytes of diploid (1.10 ± 0.96‰) and triploid (2.41 ± 1.28‰) fish at swim-up stage. Increased mean values of micronucleus in diploid (1.80 ± 1.57‰) and triploid (5.92 ± 3.80‰) fry were also recorded.


1993 ◽  
Vol 71 (11) ◽  
pp. 2167-2173 ◽  
Author(s):  
John R. Bailey ◽  
William R. Driedzic

Rainbow trout (Oncorhynchus mykiss) were acclimated to 5 and 20 °C. Oxygen consumption of isolated perfused hearts was measured at 5 or 15 °C with either glucose or palmitate as the exogenous fuel source. With glucose as the fuel there was no significant difference in oxygen consumption of hearts from either acclimation group at either temperature. With palmitate as the fuel source, hearts from fish acclimated to and tested at 5 °C had significantly higher oxygen consumption than hearts from fish acclimated to 20 °C and tested at either 5 or 15 °C. Hearts from fish both acclimated to and tested at 5 °C had a higher oxygen consumption with palmitate than when glucose was supplied. This reflects the preference for fatty acid fuels found in cold acclimated muscle tissue, and consequently the amount of oxygen required to utilize fats. Under all experimental conditions, 14CO2 production from either (6-14C)glucose or (1-14C)palmitate could account for less than 0.5% of oxygen consumption. Tissue chemical analysis showed that most of the label from (6-14C)glucose appeared in acid-soluble (glycolytic intermediates, citric acid cycle intermediates, amino acids, etc.) and lipid fractions while most of the label from (1-14C)palmitate appeared in lipid- or acid-soluble or acid precipitate (protein material) fractions. This indicates considerable dilution of exogenous fuels in endogenous pools, which could account for the discrepancy in measured O2 consumption and 14CO2 production. Glucose catabolism was little affected by either acute or chronic changes in temperature other than an increase in glucose incorporation into the glycogen pool. Hearts from fish both acclimated to and tested at 5 °C showed an increased handling of exogenous fatty acids as reflected by elevated rates of catabolism and incorporation into intracellular lipids.


2013 ◽  
Vol 58 (3) ◽  
pp. 185-193
Author(s):  
Nebojsa Savic ◽  
Milanka Drinic ◽  
Bozo Vazic ◽  
Biljana Rogic

This paper presents the results of the effects of different sizes of meals (80%, 90%, 100%, 110% and 120% regarding the amount recommended by the food producer) on the growth characteristics of young rainbow trout (Oncorhynchus mykiss Wal.) aged from 2 to 3.5 months. The experiment was carried out at the Laboratory of Aquaculture, Faculty of Agriculture, University of Banja Luka for a period of 47 days. In the experiment, there were a total of 500 fish, divided into five groups, and placed in the 55-l aquarium with a constant flow of water and the aeration system. The main parameters of water quality were analyzed every day and they included: water temperature 12.64-12.76?C, content of dissolved oxygen 7.83-8.09 mg/l, saturation of water with oxygen 75.47-77.39% and pH value 7.224-7.268. In the end, the average individual weight and body length (?standard deviation) of young rainbow trout, regarding the experimental groups (EG), were reached: EG80 10.53?2.58 g and 9.94?0.76 cm, EG90 12.14?2.97 g and 10.45?0.86 cm, EG100 13.18?2.91 g and 10.67?0.82 cm, EG110 13.80?3.14 g and 10.82?0.78 cm, EG120 14.58?3.63 g and 10.81?1.11 cm. Statistically highly significant differences were found between the means of experimental groups (p <0,01). The coefficient of condition of young rainbow trout at the end of the experiment was similar in the treatments EG80, EG90, EG100 and EG110 (1.06 to 1.09), and it was the highest in the treatment EG120 (1,15?0,17). Generally, it can be said that increasing of the size of meals up to 10% above the recommended value does not cause significant differences, and if the increase is greater than 10%, statistically significant difference in body weight occurs.


2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Tran Quoc Toan ◽  
Viet Anh Dang ◽  
Quoc Long Pham ◽  
Phi Hung Nguyen ◽  
Thu Huong Trinh ◽  
...  

Dietary inclusion of canthaxanthin, a common carotenoid pigment, has been long practiced in aquaculture to give the favorable flesh color in farmed salmonids. However, carotenoids are associated with limited solubility and poor physicochemical stability, and their dose in fish feed is widely regulated. In this study, we included canthaxanthin- and α-tocopherol-loaded liposomes into fish diets and evaluated the effects of supplemented fish feed on fish growth, color, nutrition, and canthaxanthin deposition in fillets of cultured rainbow trout (Oncorhynchus mykiss). The liposomes were fabricated using lecithin as phospholipids with the initial concentrations (IC = mcanthaxanthin/mlipids, % wt/wt) of canthaxanthin at 0.1%, 0.5%, and 1.0%. Particle size characterization showed that liposome mean sizes were 109.70 ± 6.36, 105.10 ± 8.41, and 109.20 ± 5.66 nm (mean ± SD; n = 3), respectively, corresponding with liposomes synthesized at canthaxanthin IC = 0.1%, IC = 0.5%, and IC = 1%. The polydispersity index (PDI) of all samples remained lower than 0.2. There were no significant differences in the mean size and PDI between blank lecithin liposome and canthaxanthin- and α-tocopherol-loaded liposomes. The encapsulation efficiency of canthaxanthin- and α-tocopherol-loaded liposomes decreased when increasing the concentration of canthaxanthin in lecithin liposomes, with EE% values of IC = 0.1%, IC = 0.5%, and IC = 1% being 85.3 ± 2.1, 72.9 ± 1.8, and 55.3 ± 2.6, respectively. For fish growth, at the end of the experiment, final weight was significantly higher in fish fed with diet supplemented with 1 g/kg canthaxanthin- and α-tocopherol-loaded liposomes (IC = 0.5%) in comparison to other experimental control groups. The difference in color of the salmon muscle was most apparent after two months of feeding. However, after three months, there was no noticeable change in the color score of the fish muscle, indicating saturation of color of the fish muscle. The above results suggest the potential of canthaxanthin- and a-tocopherol-loaded liposomes as the red pigment in fish aquaculture.


2019 ◽  
Vol 14 (3) ◽  
pp. 255-265
Author(s):  
Seyyed Morteza Hoseini ◽  
Behrooz Gharavi ◽  
Yousef Iri

The aim of this study was to compare gill, kidney, liver and gut histopathology, and plasma antioxidant markers of rainbow trout Oncorhynchus mykiss reared in saltwater earthen ponds in Gomishan, Iran. To this, 10000 fish were distributed in a three-ha earthen pond and 150 fish in three fiberglass tanks (2000L). Blood samples were taken after 3 months rearing with same commercial feed. The source of fish and feed was similar between the saltwater pond and fiberglass tanks. After the 3-month rearing, gill, kidney, liver and gut samples were taken from the pond fish; whereas, blood samples were taken from both the pond and tank fish. There was no significant difference in water temperature, dissolved oxygen and pH between the pond and tanks; however, water salinity and ammonia was higher in the pond compared to the tanks. Plasma superoxide dismutase and glutathione peroxidase activity of the fish in earthen ponds were significantly higher than those fish reared in fiberglass tanks; however, there was no significant in thiobarbituric acid reactive substances between the pond and tanks. The fish had various histopathological symptoms including primary and lamella hyperplasia, lamellar fusion and epithelial lifting. In the kidney section, the fish showed glomerulus shrinkage and/or disappearance, melanomacrophage aggregates and hematopoietic tissue necrosis. These fish showed necrosis and melanomacrophage aggregates in liver and goblet cell hypertrophy in gut. The results suggest that the fish in the earthen pond faced stressful conditions, which might be due to water salinity and ammonia; however, other possible factors, such as pollutants and different feeding regimen must be considered.


2021 ◽  
Vol 79 (3) ◽  
pp. 119-123
Author(s):  
Antonia Kurtela

Abstract Rainbow trout Oncorhynchus mykiss (Walbaum 1792) larvae that first started active feeding were separated into 3 replicate batches (1A, 1B, 1C) with 100 individuals each, while four days later, the fry that last started active feeding were also distributed in 3 replicate batches (2A, 2B, 2C) with 100 individuals. Four measurements were performed with an interval of four days between the first and second measurements, as well as between the third and fourth measurements, to compare the initial masses of individuals by groups (1ABC and 2ABC) on the same day from the beginning of active feeding. The average initial body weight of the fry per batch in each measurement was generally higher in the first group (1ABC) than in the second group (2ABC). However, when comparing the weight of both groups for the same number of days from the beginning of active feeding, it is noticed that the second group (2ABC) has a higher average individual weight than the first group (1ABC). There was no statistically significant difference (one-way ANOVA, p>0.05) in SGRw between the groups in the first three measurements, while there is a statistically significant difference (one-way ANOVA, p<0.05) in SGRw in the fourth measurement. Group 2ABC has a significantly higher SGRw (5.0064%day−1±0.05394) than group 1ABC (4.7711%day−1±0.01715). This leads to the conclusion that in the second group 2ABC, the backlog of 4 days in mass was compensated. It is also noted that mortality in the first group (1ABC) was only 1%, while in the second group (2ABC) it was 3.7%. Consequently, a higher density of the fry in the first group (1ABC) could have an impact on a lower growth rate.


2016 ◽  
Vol 60 (1) ◽  
pp. 25-33 ◽  
Author(s):  
Halyna Tkachenko ◽  
Joanna Grudniewska ◽  
Agnieszka Pękala ◽  
Elżbieta Terech-Majewska

AbstractIntroduction: The goal of this study was to assess the influence of vaccination against enteric redmouth disease on oxidative stress biomarkers and antioxidant defence in the muscle tissue of rainbow trout (Oncorhynchus mykiss Walbaum) vaccinated against Yersinia ruckeri in the first and second month after immunisation. Material and Methods: Healthy fish were vaccinated orally with inactivated whole cells of a virulent strain of Y. ruckeri. One and two months after immunisation the muscle samples were collected. Results: No significant difference was noted in lipid peroxidation level in either the first or second month after vaccination, while aldehydic and ketonic derivatives of oxidatively modified proteins (OMB) in the vaccinated group were significantly lower in the second month compared to those in the first month after vaccination (P < 0.05). The content of ketonic derivatives of OMB in muscles in the first month after immunisation was higher compared to untreated control. All these culminated in a depletion of glutathione peroxidase (GPx) activity and low level of total antioxidant capacity (TAC). Conclusion: Correlations between catalase activity and lipid peroxidation and TAC confirmed the pivotal role of catalase in antioxidant defence during immunisation. From a broader perspective, it is suggested that immunisation of fish with Yersinia vaccine is associated with induced free radical formation and oxidative stress. Free radicals would therefore be at least partially responsible for the induction of both humoral and cellular elements of the immunity and increased protective immunity against Y. ruckeri infection.


2020 ◽  
Vol 65 (No. 9.) ◽  
pp. 354-364
Author(s):  
Antonella Dalle Zotte ◽  
Anna Concollato ◽  
Giulia Secci ◽  
Marco Cullere ◽  
Giuliana Parisi

Post rigor mortis changes of texture, chemical and sensory properties in rainbow trout (Oncorhynchus mykiss) reared at two different temperature conditions (8 and 12 °C) were examined to better understand how different stunning methods, i.e. electroshock (E) and asphyxia with carbon monoxide (CO), can influence their evolution during refrigerated storage. Seven days after rigor resolution (T<sub>RR</sub>7), considering ATP catabolites (K- and K1-values), the freshness remained well preserved regardless of the stunning method applied and water temperature. During refrigerated storage fillets from fish reared at 8 °C maintained significantly higher (P &lt; 0.001) pH at the day of rigor resolution (T<sub>RR</sub>0), whereas at the end of the storage time (T<sub>RR</sub>7), 8 °C-reared fish showed a significantly lower pH value (P &lt; 0.05). CO treatment was effective in ensuring a more intense red colour of the fillet and high chroma, whereas E treatment exhibited the lowest a*, b* and chroma values. The texture profile analysis showed a significant effect of the stunning method (S), water temperature (T) and S × T interaction on fillet cohesiveness. TBARS values were significantly lower (P &lt; 0.05) in fish stunned by CO when compared to E group in the first 76 h post mortem (T<sub>RR</sub>0). At the end of the storage period (T<sub>RR</sub>7), no TBARS value difference was detected between treatments. The stunning method had a relevant impact on fillet sensory traits, revealing that CO fillets were the juiciest (P &lt; 0.05) and presented the lowest saltiness (P &lt; 0.05), aroma (P &lt; 0.05) and odour (P &lt; 0.01) intensity. Rearing temperature, instead, had a moderate effect on fillet sensory traits and indicated that the water temperature of 12 °C enhanced juiciness (P &lt; 0.05) and tenderness (P &lt; 0.05) attributes. Overall results suggested that CO is a suitable stunning method for trout that, coupled with 12 °C water temperature, are able to preserve fillet freshness, enhance colorimetric characteristics which are maintained during refrigerated storage, and provide desirable sensory traits.


1989 ◽  
Vol 46 (12) ◽  
pp. 2070-2073 ◽  
Author(s):  
B. Kügel ◽  
R. H. Peterson

In soft water of various pH levels, the perivitelline fluid of late eyed rainbow trout (Oncorhynchus mykiss) eggs showed significant pH buffering: final perivitelline pH was higher than ambient by 0.7–0.85 pH unit in acidified water but was lower by 0.3–1.0 pH unit in weak acidified or basic water. No significant difference between the pH of an external buffer solution and that of the perivitelline fluid could be observed after 24 h. Most rapid perivitelline pH change occurred in the first 2 h and in the first 10–20 min, when eggs were transferred from acidified to weak acid or basic water and buffer, respectively. Final pH of the perivitelline fluid was reached after 48 h in unbuffered water and 24 h or less in buffer.


2011 ◽  
Vol 80 (2) ◽  
pp. 219-225 ◽  
Author(s):  
Olga Čelechovská ◽  
Veronika Harkabusová ◽  
Blanka Macharáčková ◽  
Eva Vitoulová ◽  
Alena Lavičková

Rainbow trout (Oncorhynchus mykiss) was monitored for the duration of one year, from 2 to 14 months of age (n = 120). The study was performed on a farm with through-running water from the basin of water processing plant in the years 2007 and 2008. During the first months of fish life, we analyzed homogenized samples (n = 12) of rainbow trout bodies. From the 8th month the samples of twelve rainbow trouts were analysed. The total contents of arsenic and arsenobetaine were quantified in muscle, liver, spleen and bile separately. The total arsenic was determined by hydride technique AAS and arsenobetaine by high performance liquid chromatography combined with detection using atomic fluorescence spectrometry. The concentration of arsenic in homogenized body samples grew (P < 0.01) during the first months of life, from the 6th month of rearing no significant difference was found. The concentration of arsenobetaine in homogenized bodies was low during the first months and from the 6th month the concentration stayed on invariable level and amounted to 46 ± 6% of total arsenic. The highest concentrations of arsenic and arsenobetaine in tissues ranked in the order muscle, liver, spleen and bile. In summer months the total arsenic in muscle was bonded in the form of arsenobetaine, in winter months the content of arsenobetaine dropped to 50% of total arsenic. The content of arsenic in liver samples remained the same during the entire monitoring, however, the ratio of arsenobetaine content altered. In summer months it reached the maximum 27%, in winter months it dropped to 7% of arsenic. The concentration of arsenic in spleen and bile decreased in winter months, arsenobetaine corresponded to the value assessed in liver. This study proved the effect of the small content of arsenic in feedstuff on accumulation of total arsenic and arsenobetaine in the tissue of rainbow trout during the growing period and season.


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