Histopathological and Toxicological Evaluation of Broiler Chickens Fed Graded Levels of Enzymatically-Processed Feather Meal-Based Diet
A study was conducted to evaluate the histopathological and toxicological effects of graded levels of enzymatically treated feather meal (ETFM) as a replacement for fishmeal in broiler diets, as well as to assess its cost-effectiveness. A total of 150 unsexed day-old broiler chicks were randomly allocated to five dietary treatments (T1–T5) in a Completely Randomised Design (CRD), with three replicates of 10 birds per treatment. The treatments corresponded to 0%, 25%, 50%, 75%, and 100% replacement of fishmeal with ETFM. Feathers sourced from a local poultry processing facility were chopped, hydrolysed, sun-dried to reduce moisture content, and subsequently treated with Streptomyces fradiae to enzymatically release keratin and improve nutrient availability. The resulting ETFM contained 44.6% crude protein and was incorporated into the experimental diets. At the finisher phase, selected tissues (liver, spleen, kidney, and proventriculus) were harvested for histopathological evaluation. Results showed no observable pathological lesions in the liver, spleen, and kidney across all dietary treatments, indicating that ETFM inclusion up to 100% did not adversely affect these organs. However, a progressive but mild atrophy of the outer serosal layer of the proventriculus was noted with increasing levels of ETFM. This alteration was not significant enough to compromise normal digestive function. Furthermore, economic analysis revealed a reduction in feed cost per kilogram of weight gain with increased ETFM inclusion. It is concluded that enzymatically treated feather meal can safely replace fishmeal in broiler diets up to 75% inclusion without detrimental effects on tissue integrity or organ function. This substitution also offers a cost-saving advantage, promoting sustainable and economically viable poultry production
