Abstract
Background: Philippine native Darag chickens are widely distributed, locally adapted, and valued for preferred flavor and perceived hardiness despite slower growth, smaller body size, and leaner musculature than commercial broilers. However, baseline histomorphometric data on major organs of this breed remain limited. This study evaluated the developmental histomorphometry of the heart, lungs, and kidneys of Darag chickens compared with Redbro commercial hybrid broilers, selected because of their roles in oxygen delivery, gas exchange, and metabolic waste elimination, respectively, and the scarcity of baseline data in Philippine native chickens. Methods: Heart, lung, and kidney tissues were collected from 100 day-old male Darag and 100 Redbro chicks. Three birds per strain were sampled at weeks 1, 2, 4, 6, and 8 for histologic processing and quantitative analysis. Associations among organ parameters, body weight, and feed intake were assessed. Results: Age significantly influenced heart muscle fiber thickness, parabronchial density, and parabronchial lumen diameter, while strain affected heart muscle fiber thickness and air capillary area fraction. Significant age–strain interactions were observed across all kidney parameters. Body weight and feed intake showed positive correlations with selected cardiopulmonary morphometric parameters across strains. Conclusions: Findings provide preliminary structural baseline data; larger functional studies are recommended.
Keywords
Darag; Philippine native chicken; Redbro; Heart; Lungs; Kidneys; Histomorphology