This study investigates the effect of insect biomass derived from black soldier fly (Hermetia illucens) larvae on the morphological and biochemical blood parameters of pheasants (Phasianus colchicus). The research addresses the growing need for alternative high-quality protein sources in animal nutrition amid rising costs of conventional feed ingredients and increasing environmental requirements. The experiment was conducted on 40 clinically healthy pheasants aged 6 weeks, divided into one control group and three experimental groups receiving diets containing 5 %, 10 %, and 15 % insect biomass. Morphological parameters (erythrocyte and leukocyte counts, hemoglobin concentration, hematocrit, erythrocyte sedimentation rate) and biochemical profiles (total protein, albumin, glucose, urea, creatinine, alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activity, calcium, and phosphorus) were evaluated over a 30-day period. Dietary inclusion of Hermetia illucens biomass stimulated erythropoiesis and improved the oxygen-carrying capacity of the blood, as evidenced by increased erythrocyte counts, hemoglobin levels, and hematocrit values. Elevated leukocyte counts indicated enhanced nonspecific immune resistance. The biochemical profile showed increased levels of total protein and albumin, indicating enhanced protein metabolism and the high biological value of insect-derived protein. Higher calcium and phosphorus levels reflected a positive effect on mineral metabolism. Liver enzyme activity remained within physiological limits, confirming the safety of insect biomass use. The most pronounced positive effects were observed at a 10 % inclusion level, which can be considered optimal for feeding young pheasants.

Keywords: insect biomass, Hermetia illucens, pheasants, blood parameters, biochemical parameters, alternative protein.