Exploring the Impact of In Ovo Injection of Flavonoid‐Based Aromatase Inhibitors on Gonadal Histology Differentiation in Ross 308 Broiler Chickens

AIM OF STUDY: This study aimed to evaluate the in ovo injection of nettle extract, mushroom extract and their mixture as natural anti-aromatase on sex reversal, histological changes in ovaries and testes and carcass characteristics of Ross 308 broiler chickens. AREA OF STUDY: Sex differentiation in avian species MATERIAL AND METHODS: A completely randomized block design used to allocate 500 fertilized eggs (Ross 308 strain) in five treatments (four replicates, 25 eggs per replication). Treatments included: an injection of nettle (URE), mushroom (AGE), mushroom and nettle extract (MIX), distilled water (PC) and no injected eggs (NC). The evaluation of ovarian and testicular tissues was done histologically. MAIN RESULTS: In ovo injection of URE and MIX substances significantly lead to decreased total follicle numbers compared to positive controls (p = 0.01). The proportion of ovaries covered by connective tissue was similar to the testicular tunica albuginea in the URE, AGE and MIX groups, with coverage percentages of 75%, 50% and 62.5%, respectively, while control treatment showed 0% coverage (p = 0.0001). Hatched chickens from AGE group exhibited the highest germ/Sertoli cell ratio and germinal epithelial height in testicular tissue compared to the controls. RESEARCH HIGHLIGHTS: This study demonstrates that in ovo injection of flavonoid-based aromatase inhibitors derived from nettle and mushroom extracts, either individually or in combination, may induce mild effects on gonadal differentiation and structural changes of treated chickens. However, a final statement is subject to further research findings.