Leaves from banana (Musa nana) and maize (Zea mays) have no phyto-prophylactic effects on the susceptibility of grass carp (Ctenopharyngodon idella) to Aeromonas hydrophila infection

BMC Veterinary Research

Research Article

Richard Mayrhofer¹  Mansour El-Matbouli¹  Simon Menanteau-Ledouble¹  Johannes Pucher²  Ulfert Focken³ 

[1] Clinical Division of Fish Medicine, University of Veterinary Medicine, Vienna, Austria;Life Science Centre, University of Hohenheim, Stuttgart, Germany;Thünen-Institute of Fisheries Ecology, Ahrensburg, Germany;

关键词: Phytogenic supplement;    Feed conversion ratio;    Haematocrit;    Diet composition;    Stable isotope δC;    Stress indicator;   

DOI  :  10.1186/s12917-017-1255-5

 received in 2016-09-15, accepted in 2017-11-01,  发布年份 2017

来源: Springer

【 摘 要 】

BackgroundThe ubiquitous and opportunistic bacterial pathogen Aeromonas hydrophila has been associated with ulcerative dermatitis in fish, especially under stressful conditions. It can cause severe losses in fresh water aquaculture and is particularly prevalent in tropical and subtropical regions. Fresh leaves from maize and bananas have been used as feed supplement by fish farmers in Vietnam and it has been reported that they may have phyto-prophylactic benefits. In the present study, a feeding trial was conducted to investigate the benefits of providing maize and banana leaves as feed supplement: to determine if they were taken up and digested by grass carp (Ctenopharyngodon idella), if this uptake resulted in improved growth performance, and if leaf supplementation protected fish when challenged with A. hydrophila by intramuscular injection.ResultsAll fish were fed an identical ratio of commercial pelleted feed relative to biomass. However, in 12/18 tanks, this diet was supplemented with either fresh banana leaves or fresh maize leaves; offered ad libitum. Addition of leaves increased the overall feed conversion ratio (FCR) significantly. However, if only the pellet were taken into account, then no difference was found between treatments. Changes to the isotopic composition of the fish showed leaf nutrient uptake occurred. No prophylactic effects of feeding banana or maize leaves were detected against infection with A. hydrophila, and the diet did not induce changes in the fish haematocrit. However, addition of the maize leaves was associated with significantly reduced severity of the skin lesions, which could improve the market value of the fish.ConclusionsAddition of the leaf supplement did not result in significantly improved growth performance. Similarly, the effect of the supplement on the fish survival to infection was not significant.

【 授权许可】

CC BY   
© The Author(s). 2017