Abstract

The scarcity, high cost, and competition for conventional protein sources have made insects a valuable alternative for poultry feed, offering rich nutrition and a lower environmental footprint. This study evaluated the effects of two animal protein sources: fish meal (FM) and Tenebrio molitor larvae meal (TMLM) on the growth performance, organ development, and haematological indices of Sasso broiler chickens over an 85-day period. The study was carried out between August and October 2025 by distributing a total 360 dayold Sasso broiler chicks, randomly assigned to four treatment groups (TM4, TM6, TM8, FM8) in a completely randomized design (CRD), with five replicates of 18 chicks each. Data were collected based on parameters of interest which includes proximate analysis, growth performance, haematological indices, organ weights and morphometric indices. Statistical analyses were performed using GraphPad Prism software, version 9. Bromatological analysis showed no significant differences (p > 0.05) between FM and TMLM, though TMLM had higher crude protein, fat, and methionine + cysteine levels. Growth performance metrics, including feed intake (FI), body weight gain (BWG), and feed conversion ratio (FCR), varied significantly (p < 0.05) across treatments. Broilers fed TMLM diets (TM4%, TM6%, TM8%) exhibited improved FI, BWG, and lower FCR values compared to those fed FM8%. Relative organ weights and morphometric indices also differed significantly (p < 0.05), with TM8% yielding the highest heart, gizzard, and abdominal fat weights; TM6% showing superior liver, lung, and intestinal length; and TM4% leading in intestinal weight. Haematological indices revealed significantly higher WBC, RBC, Hb, and HCT values in TMLM-fed groups, particularly TM8%, TM6%, and TM4%, while FM8% consistently recorded the lowest values. Overall, T. molitor larvae meal enhanced growth performance, organ development, and blood profile in Sasso broiler chickens, demonstrating its potential as a viable alternative to fish meal in poultry nutrition.