Effects of Linum usitatissimum and Trigonella foenum-graecum on Growth, Digestion, Histology, Haematology and Immunity in Labeo rohita Fingerlings

Aquaculture contributes nearly half of global fish production by producing food at a faster rate. Flaxseed, rich in omega-3 fatty acids and fenugreek known for bioactive compounds like saponins and flavonoids, play significant roles in improving fish health. This study investigated the effects of dietary soluble flaxseed (Linum usitatissimum) and fenugreek (Trigonella foenum-graecum) seed meals on growth, digestive performance, histology, and immunity responses in Labeo rohita. Sixty fingerlings were divided into four groups (15 each) and fed different diets for 30 days: control (G0), G-1 (3g flaxseed meal), G-2 (3g fenugreek meal) and G-3 (6g flaxseed-fenugreek mixture). Results showed that G-2 had significantly higher final body weight (8.35±2.07 g) and specific growth rate (11.87±7.66), while FCR was highest in G-3 (8.815±1.874). Digestive enzyme activity, particularly amylase was highest in G-2. Histological analysis revealed normal liver structure and elongated intestinal villi. Immune responses varied with WBCs highest in G-1, G-1 recorded the highest lymphocyte percentages (~82–88%), G-2 recorded the lowest values (~0.9–1.1%). These findings suggest that flaxseed and fenugreek seed meals can serve as effective, natural alternatives to synthetic additives, promoting health and growth in aquaculture species. Further research on different doses and combinations could optimize their application for large-scale production. This approach supports sustainable aquaculture and reduces dependence on chemical growth promoters.