Influence of Tenebrio molitor Meal Inclusion (25–45%) on Clinical and Behavioral Responses in Laboratory Rat Feeding Trial

Although Tenebrio molitor is increasingly explored as a feed ingredient, uncertainty remains regarding the effects of high dietary inclusion levels in model animals. Therefore, this study evaluated physiological and behavioral responses to graded inclusion levels of T. molitor meal (25–45%) in the diets of adult female Wistar rats. The assessed outcomes comprised (i) clinical parameters, (ii) food and water intake, (iii) hematology and serum biochemistry, and (iv) behavior. Across the insect-fed groups, no unintended weight loss or excessive gain was observed; instead, animals modulated their feed intake in a manner consistent with maintaining a relatively stable growth trajectory, without signs of hyperphagia suggestive of nutrient deficiency or anorexia indicative of adverse effects under study conditions. Diet acceptance remained high throughout the experiment, with no feed refusal or behavioral evidence of aversion that might be expected in response to poor palatability or discomfort. Heart rates and respiratory rates remained age-appropriate, showing typical temporal variability. Significant between-group differences were observed in RDW, Retic (%), NEU (%, K/μL), EOS, PLT, and PCT (p < 0.05), while serum analyses revealed significant differences in AST, total bilirubin, creatinine, phosphorus, and BUN (p < 0.05). A moderate negative correlation between individual feed intake and body weight was additionally identified in selected groups. The results of behavioral testing reveal that the dietary inclusion of T. molitor meal at levels up to 45% did not reduce spontaneous activity or elicit anxiety-like responses, and exploratory behavior appeared to be preserved. Overall, the present findings indicate that the gradual incorporation of T. molitor meal at high inclusion levels supported normal growth, physiological function, and behavior in rats under the conditions studied.