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Gross Morphological and Morphometric Studies on Digestive Tracts of Three Nigerian Indigenous Genotypes of Chicken with Special Reference to Sexual Dimorphism
Authors: Muhammad Abdullahi Mahmud
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Gross and morphometric studies were carried out on the Gastrointestinal Tracts (GIT) of three
Nigerian indigenous genotypes of chicken with special reference to sexual dimorphism. Eighteen
adult chickens of the three genotypes (three male and three female per genotype, all above one
year of age) were bought from Mokwa local markets. They were quarantined for two weeks,
stabilized for another weeks, live weights taken and then slaughtered using Halal method. After
careful evisceration, GIT segments were examined grossly and then weights, lengths, thickness
and width of the segments were obtained. The GIT of Normal feathered (No), Naked neck (Na)
and Frizzle feathered (F) genotypes like in other breeds of chicken was found to consist of the
crop, an expansion of the esophagus, located in the lower neck region, the glandular stomach
(proventriculus), the muscular stomach (ventriculus), small intestines (duodenum, jejunum and
ileum) and large intestine (ceca and colorectum). The mean weights, lengths, thickness and widths
of esophagus, proventriculus, ventriculus, small intestine and large intestine of the three genotypes
studied were not significantly different from one another, except the weight of oesophagus and
width of ventriculus. Also, no significant difference was found between male and female when the
means of these parameters were compared irrespective of genotype involved. In conclusion, all the
three genotypes have similar gross and morphometric patterns and in addition their ileum was the
longest portion of the intestine in contrast to what was reported in other breeds of chicken in the
literature.