Evaluation of Diet Supplementation with Wheat Grass Juice on Growth Performance, Body Composition and Blood Biochemical Profile of Carp (Cyprinus carpio L.)

Simple Summary Phytogenics are feed additives of plant origin, that gained considerable attention due to the wide range of benefits for farmers and animals, as well as for the environment. Phytogenics can be used to stimulate growth, strengthen the immune system, promote intestinal flora, or reduce intestinal inflammation in fish. In this study, the effect of feed supplementation with wheatgrass juice as a phytogenic on the growth, body composition and blood biochemical profile in carp was tested. The results showed that wheat grass juice produces positive effects on growth, contributing to higher final biomass while reducing the fat content of meat. At the same time, the content of albumin, globulin, total protein, and calcium in the blood increased in wheat grass juice feeds. This study opens the premises for the use of wheat grass juice as a feed additive for carp. Wheat grass juice (WGJ) is an extract of young wheat plantlets (Triticum aetivum L.) used worldwide for its health related properties. In this study, the following feeds containing WGJ were tested on common carp (Cyprinus carpio L.): Control (C), WGJ1% (V1), WGJ2% (V2) and WGJ4% (V3) w/w. Fish with an average initial weight of 102 g/individual were grown in a recirculating aquaculture system. The results showed that WGJ had stimulatory effects on growth performance. Accordingly, final body weight increased by 11% at V1, 39% at V2 and 23% at V3, while other indices (feed conversion ratio, specific growth rate, relative growth rate, protein efficiency ratio, and condition factor) were unaffected. Body composition analyses revealed a significant decrease in fat content at V2 and a significant increase in collagen and ash at the same variant, while the protein content was unmodified. Regarding the blood profile, significant increases in the content of albumin, globulin, total protein, and calcium were recorded in the variants with WGJ. The positive results of WGJ on carp can be attributed to its biochemical composition, which is rich in chlorophyll (4.71 mg mL(-1)), total phenols (164 mu g mL(-1) gallic acid equivalents), and high antioxidant activity (67% inhibition of DPPH 2,2-diphenyl-1-picrylhydrazyl). The results suggest WGJ can be used as a promising feed additive for common carp.