Different plant extracts have shown immunostimulatory effects, improved growth or increased survival against pathogens in rainbow trout.
Seeds of Coriandrum sativum contain vitamin C, some fatty acids (omega 6) and minerals (Mg, Fe, Ca, Zn and K). In addition, they also contain 40-50% linalool, a terpenoid characterised by its antioxidant, antimicrobial and anti-inflammatory properties.
According to the authors of a new study, there are no data on the effect of the incorporation of coriander seed extract (CSE) in the diet of rainbow trout.
Therefore, they decided to investigate the long-term effects of CSE on growth, immunity and resistance to disease caused by the pathogen Yersinia ruckeri, when it was incorporated into the diet of 600 trout (approximately 62 grams) for eight weeks.
The fish were divided into four groups in which 0, 0.5%, 1% and 2% of CSE were included in the feed.
“In the present study, rainbow trout fed 2% CSE showed significantly higher values in the specific growth rate (SGR), final weight and condition factor compared to the control group,” the scientists said in their results.
Additionally, fish of the same group had the highest activity levels of lysozyme (bactericidal enzyme) and complement system (component of the immune response).
After eight weeks, the researchers infected 30 fish from each group with the pathogen Yersinia ruckeri intraperitoneally and continued the study for an additional 14 days.
“The fish fed with CSE, especially the group with 2% inclusion, improved the survival rate against Y. Ruckeri,” said the authors. However, there were no significant differences between the fish in the control group and those with different levels of CSE inclusion, according to the researchers.
As stipulated by the researchers in their results, the incorporation of CSE in the diet can improve growth factors, immunological indices and the resistance of rainbow trout against Y. ruckeri infection.
Read the abstract of the study entitled “Dietary effects of Coriandrum sativum extract on growth performance, physiological and innate immune responses and resistance of rainbow trout ( Oncorhynchus mykiss ) against Yersinia ruckeri” here.