Effect of Diets Containing Herring Oil Oxidized to Different Degrees on Growth and Immunocompetence of Juvenile Coho Salmon (Oncorhynchus kisutch)

1988 ◽  
Vol 45 (12) ◽  
pp. 2187-2194 ◽  
Author(s):  
Ian Forster ◽  
David A. Higgs ◽  
Gordon R. Bell ◽  
B. S. Dosanjh ◽  
B. E. March

Growth rate and efficiency of feed conversion were reduced by inclusion of oxidized herring oil in the diet, presumably as a result of reduced digestibility of the oxidized oil and suboptimal dietary concentrations of ω3 fatty acids. There was no evidence of any toxic factors in the oxidized oil. There was no significant difference in growth rate or the efficiency of feed conversion between juvenile coho fed diets supplemented with 30 and 1030 IU vitamin E/kg. Dietary treatment did not affect haematocrit values. Immunocompetence, judged by antibody titres in response to vibrio vaccination, was similar for all treatments. Disease resistance, assessed by the rate of mortality induced by exposure of nonvaccinated fish to challenge with Vibrio anguillarum or V. ordali, was likewise unaffected by the dietary treatments.

1993 ◽  
Vol 50 (4) ◽  
pp. 759-766 ◽  
Author(s):  
Kira Salonius ◽  
George K. Iwama

Coho (Oncorhynchus kisutch) and chinook salmon (0. tshawytscha) from aquaculture and wild environments were subjected to handling (30–60 s of netting and aerial emersion) and disease challenges. Plasma cortisol concentrations ([cortisol]pl) in both coho and chinook salmon from wild environments were significantly elevated 4 h after handling. Colonized coho salmon (hatchery-reared fish, transported into a natural water body as fry) responded in a similar fashion to wild fish, while those reared entirely in the hatchery showed no significant rise in [cortisol]pl. The responses to handling stress were retained in wild and colonized coho salmon after 7 mo of hatchery rearing. A transient increase in the leukocyte to red blood cell ratio in both wild and hatchery-reared chinook salmon occurred 4 h after handling. Handling signficantly decreased the antibody-producing cell (APC) number in wild fish and elevated their [cortisol]plrelative to hatchery fish. Wild fish had the highest APC number among the three groups before the handling. No difference in resistance to Vibrio anguillarum was apparent in coho and chinook salmon among the different rearing environments, although chinook salmon were generally more susceptible; disease resistance was reduced in wild coho salmon after 7 mo of rearing in a hatchery.


2021 ◽  
Vol 21 (06) ◽  
pp. 275-281
Author(s):  
Ilhan Aydin

Triploidy induction is a useful tool to produce sterile fish that prevents interbreeding of farmed fish with wild counterparts. In this study, growth performance and feed conversion rates of 12-months old diploid and triploid turbot that reared both communally and separately for 16 months at constant water temperature determined. At the end of the experiment, diploid, triploid, and communally reared groups reached an average weight of 672.4±21.0 g, 659.2±25.3 g and 660.5±12.0 g, respectively. Any significant differences were not observed in the weight of separately reared diploid and triploid turbot groups. In contrast, triploid fish in the communal group were significantly heavier than diploids at the end of the rearing period. The feed conversion rate of the ploidy group did not show any significant difference between groups. The highest mean specific growth rate was observed in the triploids in communal groups, whereas the diploids in communal groups had the lowest mean specific growth rate. The weight and length gain rates of the groups were similar. Diploid turbot growth appeared to be negatively affected by communal ploidy rearing. The results of the present study indicate that triploid turbot farm escapees may be advantageous in terms of growth in nature.


2021 ◽  
Vol 37 (1) ◽  
pp. 61-70
Author(s):  
M. B. Ngele ◽  
T. A. Adegbola ◽  
S. E. F. Bogoro ◽  
M. Abubakar ◽  
D. J. U. Kalla

A study was conducted at the Abubakar Tafawa Balewa University (ATBU) Research and Teaching Farm between December and May 2006 to determine nutrient intake, digestibility and growth performance in Yankasa rams fed urea-treated (UTRS) and untreated rice straw (URS) with supplementation. Thirty-two (32) Yankasa rams with an average weigh of 17.5kg, and aged 1.5 to 2 years old were alloted to eight (8) dietary treatments with four (4) rams per treatment in a 2 x 4 factorial design. The two basal feeds were urea0treated rice straw (UTRS) and untreated rice straw (URS). The supplements were maize bran (MB), MB + sun-dried poultry litter (MB + SDPL), MB + ensiled poultry litter (MB+ EPL) and MB + cotton seed cake (MB + CSC). Total dry matter intake (TDMI), daily basal feed intake (DBFI) were significant (P<0.05) across dietary treatments. Animals on supplements MB and MB+CSC for both UTRS and URS recorded the lowest and highest DBFI. The digestible crude protein intake (DCPI) and digestible organic matter intake (DOMI) were high for rams on UTRS and the values ranged from 17.72 to 28.36g/d and 288.81 to 482.66g/d for DCPI and DOMI respectively. Nutrient digestibility was improved by treatment of straw and supplementation. However, crude protein digestibility was similar for animals fed URS but, significantly (P<0.05) lower compared to those fed UTRS which were also similar across supplements. Average daily weight gain ranged from 53.58 to 91.18g/d across dietary treatment with animals on supplement MB recording the lowest (53.58 and 61.43g/d for URS and UTRs respectively) and those fed supplement MB+CSC the highest (81.38 and 91.18g/d fro URS and UTRS respectively) irrespective of straw treatment. Feed conversion ratio (FCR) was least for animals on supplement MB+CSC for both URS and UTRs, indicating that this supplement (MB+CSC) influenced feed utilization more positively. From the results of this trial, it may be concluded that straw treatment and/or supplementation can enhance crop residue utilization by sheep. however, mixed supplements especially MB+CSC were more efficient in enhancing the utilization of the straw and consequently animal performance.    


1970 ◽  
Vol 1 ◽  
pp. 269
Author(s):  
Phyo Htet Htet Kyaw, Kyaw San Win, Khin Khin Lay ◽  
Kyaw Kyaw Moe ◽  
Aye Aye Maw, Khin Hnin Swe

A total of 200 Cobb 500 male broilers were randomly allocated to 4 treatments consisting of 5 replications with 10 chicks each in order to evaluate the effect of dietary garlic and thyme seed supplementation on the production performance, carcass yield and gut microbial population. Treatments were control diet (T1), control diet with 1% thyme seed powder (T2), control diet with 1% garlic powder (T3) and control diet with 0.5% thyme seed and 0.5% garlic powder (T4). Feed intake, body weight, weight gain, feed conversion ratio (FCR), carcass yield was not significantly (p>0.05) improved by dietary treatments compared to control. Escherichia coli (E. coli) count in the gut of broilers did not show significant difference among dietary treatments. However, Lactobacilli count in the gut of broilers significantly (p<0.05) increased in T2 compared to that of T1. Lactobacilli count in the gut of broilers received T1, T3 and T4 did not differ significantly (p>0.05) with each other. It was concluded that thyme seed was reliable as feed additive in the broiler diet and could provide positive advantages to the colonization and proliferation of Lactobacilli.


1997 ◽  
Vol 75 (2) ◽  
pp. 335-337 ◽  
Author(s):  
Anthony P. Farrell ◽  
William Bennett ◽  
Robert H. Devlin

We examined the consequence of remarkably fast growth rates in transgenic fish, using swimming performance as a physiological fitness variable. Substantially faster growth rates were achieved by the insertion of an "all-salmon" growth hormone gene construct in transgenic coho salmon (Oncorhynchus kisutch). On an absolute speed basis, transgenic fish swam no faster at their critical swimming speed than smaller non-transgenic controls, and much slower than older non-transgenic controls of the same size. Thus, we find a marked trade-off between growth rate and swimming performance, and these results suggest that transgenic fish may be an excellent model to evaluate existing ideas regarding physiological design.


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