STUDY ON POSTNATAL GROWTH AND DEVELOPMENT OF CROP AND PROVENTRICULUS OF DIGESTIVE TRACT OF BROILER

The experiment was carried out to investigate postnatal growth and development of crop and proventriculus of digestive tract of broiler. Total 45 (“Cobb-500”) chickens of three age groups like day 1(D1), day14 (D14), day 28 (D28) were used each group containing fifteen chickens. All birds were slaughtered after respective days then crop and proventriculus were collected. Total length, diameter and weight were determined by “slide calipers” and electronic balance. Then the samples were processed and stained with H and E stain for histological study. The length (cm), diameter (cm) and weight (gm) of crop and proventriculus were increased gradually with the age where highest at 28 and lowest at day 1. Number of mucosal folds of crop was highest at 1 and lowest at day 28. The keratinized stratified squamous epithelium of crop was thickest at day 28. Submucosa contains thin loose connective tissue. Tunica muscularis contains thick inner circular and thinner outer longitudinal smooth muscle and externally covered by adventitia. The mucosa of the proventriculus has macroscopic papillae with numerous folds and lined by simple columnar epithelium. Submucosal glands are lined by simple cuboidal to low columnar epithelium. Lamina propria contains loose connective tissue and muscularis contains scattered bundles of smooth muscle. Tunica muscularis consists of smooth muscle and externally covered by serosa.