Gross Morphological and Morphometric Studies of Oviduct in Three Genotypes of Nigerian Indigenous Laying Chickens

The Nigerian indigenous chickens play major roles not only in rural economics but also contribute substantially to the gross national product [1]. They have remained predominantly in villages because of their inherent advantages over the exotic breed. Most of the birds are kept in small flocks under a scavenging system and the feed resources for the birds are household refuse, homestead pickings, crop residues, herbage, seeds, green grasses, earthworms, and small amount of supplemented feeds offered by the flock owner. They are well adapted to the adverse climatic conditions of the tropical environment and low management inputs. They contain a highly conserved genetic system with high levels of heterozygosity [2]. These indicate that they are highly important farm animals, kept for good source of animal protein, for income and socio-cultural roles. Momoh et al. [3] reported the adaptive potentials of the Nigerian indigenous chicken to varied ecological conditions, stresses and diseases. One of these adaptive potentials is the ability to produce a reasonable number of eggs when compared to their counterpart hybrids raised under intensive conditions. The Nigerian local chickens (naked neck, frizzled and normal feathered) constitute about 80% of the 120 million poultry birds. These varieties, particularly the naked neck have been reported to possess a good egg laying characteristics [4]. Since the success of the local chicken enterprise depends on the total number of quality eggs produced [5], and then understanding the normal morphology of the oviduct of these local chickens becomes paramount. The chicken oviduct is a tubular organ responsible for the secretion of the components surrounding the yolk and transport of the egg. Functional and healthy oviduct is essential for both quantity and quality of egg [6]. Any disorder that affects the reproductive system will have a great bearing on production potential and incur a heavy loss. The female genital apparatus of the chicken is composed only of the left ovary and oviduct. The oviduct is a highly convoluted, muscular duct, which is suspended from the left side of the abdominal cavity by the dorsal ligament [7]. The oviduct consists of five distinct regions the infundibulum, the magnum, the isthmus, the shell gland (or uterus) and the vagina [8]. Major genes effect on growth, fertility, hatchability and semen quality characteristics have also been reported [9-12]. Wekhe [13] earlier reported that Nigerian indigenous chickens are more resistant to infectious disease agents than their exotic counterparts. While there are reports in the literature about growth, fertility, hatchability, reproductive performance and semen quality of the Nigerian indigenous chicken, reports on genotype/strain differences on the gross morphology and morphometry of their oviducts are scanty. Therefore, this study was undertaken to highlighting terms of gross morphology and morphometry, the oviducts gross architectural differences or similarities in the three Nigerian genotypes of Chicken. Volume 5 Issue 4 2017