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United States Department of Agriculture

Agricultural Research Service

Research Project: Genetics, Physiology, and Health Research to Improve Catfish Production

Location: Warmwater Aquaculture Research Unit

Title: Growth enhancement of rainbow trout (Oncorhynchus mykiss) by passive immunisation against somatostatin-14

Authors
item Lakeh, Amir -
item Farahmand, Hamid -
item Mirvaghefi, Alireza -
item Kloas, Werner -
item Trubiroha, Achim -
item Peterson, Brian
item Wuertz, Sven -

Submitted to: Aquaculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 25, 2013
Publication Date: N/A

Interpretive Summary: Somatostatin-14 (SS-14) is a hormone that negatively regulates growth hormone (GH) production in mammals and fish. We made antibodies to SS-14 using the egg yolks from laying hens. Fish were immunized weekly (0, 7, 14, 21, 28, 35 d) with chicken egg yolk derived immunoglobulin (IgY) against SS-14 and compared to the control group that received placebo immunization. Immunization increased weight gain of treated fish (68 g) compared to the control group (41 g) after 35 days. Food conversion ratio (FCR) was improved in the immunized fish (0.6) compared to control group (1.1). The concentration of growth hormone (GH) and insulin-like growth factor-I (IGF-I) in fish plasma showed no difference between treatments. Similarly, there was no difference in pituitary GH or liver IGF-I mRNA expression between treatments, suggesting short lasting effects upon immunization with SS-14 antibody. The results of this study showed that passive immunization of rainbow against SS-14 using a chicken egg yolk derived SS-14 antibody increased growth rate and improved FCR. The mechanism of action through which passive immunization increased growth and improved FCR was not determined in this study. This technique offers the potential to improve growth of fish within the aquaculture industry, but oral application techniques should also be explored.

Technical Abstract: Juvenile rainbow trout (Oncorhynchus mykiss) were passively immunised against somatostatin-14 (SS-14) using an antibody originating from egg laying chicken (Gallus domesticus). Fish were immunised weekly (0, 7, 14, 21, 28, 35 d) with chicken egg yolk derived immunoglobulin (IgY) against SS-14 (1:25 IgY, 5 mg / ml ) and compared to the control group that received placebo immunisation with PBS. Passive immunisation significantly increased (p < 0.05) weight gain of treated fish (67.7 ± 22.1 g) compared to the control group (40.5 ± 15.3 g) after 35 days (p < 0.05). Food conversion ratio (FCR) was significantly improved in the immunised fish (0.6 ± 0.2) compared to control group (1.1 ± 0.7) (p < 0.05). The concentration of growth hormone (GH) and insulin-like growth factor-I (IGF-I) in fish plasma showed no significant difference between treatments (p > 0.05). Similarly, no significant difference of pituitary GH and liver IGF-I mRNA expression was observed between treatment and control at each sampling time (p > 0.05), suggesting short lasting effects upon immunisation with anti SS-14. There was no indication of a long lasting effect of repeated immunisation on GH or IGF-I plasma concentrations or mRNA expression. The results of this study showed that passive immunisation of rainbow against SS-14 using a chicken egg yolk derived SS-14 antibody increased growth rate and improved FCR. This technique offers the potential to improve growth of fish within the aquaculture industry, but oral application techniques should be explored in the future.

Last Modified: 8/21/2014
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