Dietary chia seed oil enhances growth, immunological response, and disease resistance against aeromonas hydrophila in common Carp (Cyprinus carpio)

Abstract

This study was conducted to evaluate the effects of chia seed oil (CSO; Salvia hispanica L.) on the growth performance, haematological-biochemical parameters, immune-related gene expression, and disease resistance to Aeromonas hydrophila in common carp (Cyprinus carpio). The fish were fed diets containing 0%, 0.5%, 1%, and 2% CSO for 60 days. The results showed a significant improvement in final weight, specific growth rate (SGR), and feed conversion ratio (FCR) in fish fed diets containing 1% and 2% CSO compared to the control group. Haematocrit (Hct) and haemoglobin (Hb) levels increased in the CSO groups, while serum triglyceride and cholesterol levels decreased significantly, particularly in the 1% CSO group. The observed decrease in liver enzyme activities (AST, ALT) suggested a hepatoprotective effect of CSO. In the stress test with A. hydrophila, the highest survival rate (80%) was recorded in the 2% CSO group. Furthermore, gene expression analyses performed on spleen tissue revealed an increase in the expression of pro-inflammatory cytokines such as TNF-alpha, IL-1 beta, and IL-8 in the groups fed with CSO, particularly at the 1% level. These findings indicate that adding 1-2% CSO to carp feed promotes growth, improves lipid metabolism, strengthens immune status, and increases resistance to bacterial infection. Consequently, the use of CSO as a sustainable and functional additive to fish oil in fish feed is suggested.