Six different poultry species (Indigenous chicken, Broiler, Turkey, Geese, Duck and Guinea fowl) were studied under extensive system of management to investigate the effect of rearing system on egg quality, cholesterol level and the blood biochemical profile. Birds used for the study were obtained from four different locations (Zangon Shanu, Bomo, Samaru and Kurmin Bomo) in Sabon Gari Local Government Area of Kaduna State. Eighteen (18) birds were randomly selected from the flock with three birds (3) per strain as replicates. Three eggs were collected daily per replicate for the determination of external and internal egg quality parameters (egg weight, egg length, egg breadth, egg shape index, shell thickness, yolk width, yolk height and yolk index). Blood samples (2ml) were collected from the same birds at the end of the laying phase for the determination of blood biochemical profile, heamatological parameters and cholesterol levels. Data collected was analyzed using the General Linear Model of the SAS (2002) Software. Statistically significant means were separated using the Duncan Multiple Range Test (DMRT). Results obtained from the study showed that the geese had significant (P<0.05) better external and internal egg parameters for most of the parameters while indigenous chicken and guinea fowl had the least results for external and internal egg parameters. Biochemical indices, showed significant (P<0.05) differences in most of the parameters except high density lipoprotein (HDL) which was not significant (P>0.05) among the treatments. The calcium (Ca2+) and phosphorus (PO42-) contents of the blood were all within a similar range (P<0.05) for the species except for duck which had a lower value of 2.06mg/dl. Also, duck had lowest values for blood total cholesterol (3.33mg/dl), low density lipoprotein (2.20mg/dl) and triglycerides (0.43mg/dl). However, lowest values of PO42- were observed in guinea fowl (0.84mg/dl) compared to duck (1.60mg/dl). Other biochemical indices such as total cholesterol (5.63mg/dl), high density lipo-protein (1.27mg/dl) and low density lipo-protein (3.93mg/dl), were significantly (P<0.05) better in goose than other species. Guinea fowl had higher albumin content (45.00mg/dl) compared to indigenous chicken (26.33mg/dl). The egg cholesterol level differed significantly (P<0.05) in the poultry species with highest level obtained in guinea fowls 15.30mg/dl) compared to indigenous chicken (8.83mg/dl), broiler (9.50 mg/dl) and duck (9.50 mg/dl). Indigenous chicken had higher value for glucose (176.33mg/dl) compared to geese (47.67mg/dl), though least for cholesterol. Duck and turkey have higher values (P<0.05) for egg total protein than broiler (53.33 vs. 28.67mg/dl). The results of heamatological parameters showed that all the parameters measured were significantly (P<0.05) different amongst the species. However, the monocytes, eosinophiles and bands were not significantly (P>0.05) different from each other. It was therefore concluded that differences exist among the various species of poultry birds studied with guinea fowl (15.30mg/dl) having the highest total cholesterol values for egg quality parameters while the lowest value (8.83mg/dl) was obtained in indigenous chicken. However, duck (3.33mg/dl) had lowest values for total cholesterol in the blood and higher values for total protein (53.33mg/dl), while indigenous chickens had the least value for egg cholesterol compared to the nutritional standard for hen (410.00mg). Hence, egg and meat of duck and indigenous chickens are safer to consume compared to other poultry species; and should therefore be promoted in our farming systems.

CHAPTER ONE: INTRODUCTION

1.1    Background of the Study
The poultry industry is a highly profitable business in Nigeria (Adebambo et al., 1999) and it is one area of animal production with significant contribution to human food production in egg and meat. Poultry products provide protein of high biological value (Epstein, 1990). Nigeria is endowed with many poultry species which are indigenous to the country and includes: the domestic fowl, pheasant, quail, guinea fowl, pigeon, turkey, goose and Muscovy ducks (Oluyemi and Roberts, 2007). These have lived, adapted and reproduced for several years in the Nigeria environment. Food and Agriculture Organization (2001) estimated poultry population in Nigeria to be about 33million.
With the ever-growing population and improvement in the living standard of Nigerians, the demand for egg and other poultry products will continue to grow. As this increase continues, the quality of food, a substantial part of which is formed by the poultry and other agricultural animals becomes increasingly important with growing consumer awareness for healthy aspect of food. The health concerns include not only pathogens or traces of contaminations but also the compositions and nutritional values of the products (Mennicken et al., 2005).
Egg is the only complete food material because it contains all of the six classes of food. Its nutritive quality for both man and for the transformation of a fertile egg into a living organism makes it a perfect biological composition (Trziszka, 2000). As a complete food, eggs are inexpensive and low calorie source of nutrients such as folate, riboflavin, selenium, choline vitamin-12 and vitamin A, K and D. The lipid matrix of the egg yolk serves to enhance the bio-availability of nutrients such as lutein and zeaxanthin (Herron and Fernadez, 2004).
The physiology and chemistry of blood are being used daily as indicators for various diseases in birds (Harr, 2002; Hauptmanova et al., 2006). However; these values are affected by different factors such as nutrition, age and sex and presence or absence of disease (Fudge 2000; Kececi and Col, 2011).
In many species of birds, normal values for biochemical factors have been measured and a comprehensive data base was established as their blood profiles (Albokhadaim et al., 2012). However, there is no sufficient information about the egg cholesterol levels and blood biochemical profile of the six poultry species in Nigeria.

1.2    Statement of the Research Problem
Some disease populations such as type II diabetics and hyperlipidemics (those with high blood triglycerides) are at greater chance for low density lipoprotein (LDL) increases in these populations relative to eggs consumption. No studies have currently shown an increase in risk of coronary heart disease, suggesting that measuring circulating cholesterol levels may be poorly indicative of heart disease from egg intake. Most dietary deficiency diseases are caused by a lack of protein, vitamins, or minerals. Cholesterol content of chicken eggs continues to receive considerable attention since the cholesterol levels in eggs are concern to humans who are trying to lower the intake of dietary cholesterol through other sources. Though many authors have examined the relationships and possible differences amongst the poultry species, conclusions from such studies has not been agreed on and comparisons between the poultry species under extensive system of management has not been made with respect to the blood chemistry and egg cholesterol status. Therefore this study was undertaken to investigate the cholesterol levels and blood biochemical profile of the six poultry species under extensive management system.

1.3    Justification of the Study
In Nigeria, more emphasis is laid on the production of domestic fowl to the neglect of other species of poultry. As a result, domestic fowl constitutes 91% while guinea fowl, duck, turkey and others constitute 4, 3 and 2% respectively (Adenowo et al., 1999). There are no any social or religious stigmas attached to the use of poultry meat in human diet. Hence the demand is high for live birds from local markets either for home consumption or as gifts at the time of festivities such as Christmas, New Year, Easter, Id El-Fitri, etc. Restaurants, hotels and supermarkets in Nigeria are noted for fast food business that involves the sale of products like chicken burger, egg rolls among others. Besides, fowl meat has good potential for export worldwide while exportation of eggs into some West African countries is a lucrative business (Samuel ,2007).
The household poultry production system is based on scavenging indigenous domestic chickens accompanied by local chickens, pigeons, guinea fowls, ducks or turkeys (Elagib et al., 2012). The haematological and serum biochemical parameters provide valuableinformation on the immune status of animals (Kral and Suchy, 2000). Such information, apart from being useful for diagnostic and management purposes, could equally be incorporated into breeding programmes for the genetic improvement of indigenous chickens. It is desirable to know the normal physiological values under local conditions for proper management, feeding, breeding, prevention and treatment of diseases.

1.4    Aim of the Study
To evaluate the internal and external egg parameters, haematological and blood profiles of six different poultry species reared extensively.

1.5      Objectives of the Study

1. To compare the egg morphometric parameters of the six different poultry species reared extensively.
2. To determine the biochemical parameters (blood profile) of the six different poultry species
3. To determine the egg quality of six different species of poultry reared extensively
• egg weight,
• egg length,
• egg breadth,
• egg shape index,
• shell thickness,
• yolk width,
• yolk height and
• yolk index.
4. To determine the haematological parameters of the six different poultry species reared extensively.

1.6    Hypotheses of the Study

1. There is no difference in the egg morphometric parameters of the six poultry species under extensive management system.
2. The biochemical parameters (blood profile) of the six different poultry species does not differ significantly (p<0.05).
3. The egg quality parameters of the six different bird species are the same.
4. There is no difference in the haematological parameters of the six poultry species under extensive management system.