Effects of Tomato Paste By-Product Extract on Growth Performance and Blood Parameters in Common Carp (Cyprinus carpio)

SIMPLE SUMMARY: The purpose of this research is to evaluate the effects of a tomato paste by-product extract as a dietary supplement for common carp (Cyprinus carpio). At the end of a feeding trial, fish fed with experimental diets showed enhanced growth performance that is key for aquaculture, and a reduced feed conversion ratio, another critical parameter. Hematology parameters such as erythrocyte count (RBC), hemoglobin content (Hb), and hematocrit (Hct) increased in fish feed with the enriched diet. Additionally, blood glucose, cholesterol, and triglyceride levels in common carp fed diets supplemented with tomato paste by-product extract reduced while total protein, albumin, and globulin levels increased. In conclusion, tomato paste by-product extract has the potential to be utilized as a feed additive in aquaculture feeds to enhance health status monitored by blood parameters and stimulating the growth parameters of common carp. ABSTRACT: This research examined different growth performances and blood parameters of common carp (Cyprinus carpio) consuming diets supplemented with tomato paste by-product extract (TPE). Five diets with different concentrations of TPEs, 0% (TPE0) 0.5% (TPE0.5), 1% (TPE1), 2% (TPE2), and 5% (TPE5) were supplied to 300 common carp (8.38 ± 0.18 g) (60 fish per group) each day during the 60-day feeding trial. The relative and specific growth rates of fish-fed supplemental diets increased significantly, while the feed conversion ratio significantly decreased (p < 0.05). TPE considerably increased the erythrocyte count (RBC), hemoglobin content (Hb), and hematocrit (Hct) (p < 0.05), according to hematological analyses of blood samples collected after the feeding experiment. The blood biochemical findings indicate that using 1% or more extracts considerably reduced the serum glucose, cholesterol, and triglyceride ratios while significantly increasing the total protein, albumin, and globulin ratios in common carp (p < 0.05). Based on the findings of the study, it was concluded that the 2% extract generated from tomato paste by-products in common carp diets could be utilized as a growth-promoting product without any negative effects on blood parameters linked to feeding in carp.