1.1 BACKGROUND OF THE STUDY
Poultry production is one area of animal production with significant contribution to food security. It provides products such as eggs and meat protein of high biological value (Jay and Michael, 2004). Eggs and meat are amongst the most nutritious foods. Eggs are rated with milk as the best protein foods rich in iron (Fe) and vitamins (Oluyemi and Roberts, 2000).
In recent years, interest has been developed in many countries in the collection and extended use of medicinal plant extract for alternative production purpose. These plants extracts are used as feed additives and added in layer diet to improve its productive performance, early age laying and egg quality (Griggs and Jecob, 2005).
A whole range of plants derived dietary supplements, phytochemicals and pro-vitamins that assists in maintaining good health and combating diseases are now been described as functional foods, nutriceuticals and nutraceuticals. Many works have been undertaken, which aim at knowing the different antimicrobial and phytochemical constituents of medicinal plants and using them for the treatment of microbial infection as possible alternation to chemically synthetic drugs to which many infectious microorganisms have become resistant (Akinpelu and Onakoya 2006). Plants serve as an indispensable constituent of poultry diet supplying the birds with mineral salts, vitamins and certain hormone precursors, in addition to protein and energy (Sheetal and Jamuna, 2009).
Eggs have been a human food and are one of nature’s nearly perfect protein foods, offering nutrients of great biological value as vitamins, minerals and fatty acids daily required for growth and maintenance of body tissues (Belitz; Grosch; Schieberle, 2009). However, during egg storage, some components of albumen and yolk may alter and tend to deteriorate egg quality. The main factors directly associated to egg deterioration are temperature and relative humidity conditions, besides manipulation and storage time. An intense transformation occurs 72 h after posture, the dense layer becomes liquid, and consequently albumen loses its quality. Therefore, less time between laying and preservation methods is required, besides suitable transportation to the retail market (Oliveira Oliveira, 2013).
1.2 EGG STORAGE CONDITIONS
From posture to consumer table, egg is subjected to physicochemical changes either in yolk or albumen that may modify flavour, freshness and palatability. The longer the storage time, worse will be the egg internal quality because carbon dioxide transfer through egg shell is favoured by temperature and humidity (Oliveira; Oliveira, 2013). Cold storage preserves eggs for 6 to 9 months, with a particularly increased shelf life with subcooled storage at −1.5 °C (Belitz; Grosch; Schieberle, 2009). Packing eggs under modified atmosphere increase their internal quality up to 28 days (Giampietro-Ganeco et al., 2015).
1.3 EGG QUALITY PARAMETERS
For many years the most important external and internal egg quality traits have been shown to be egg weight, egg shape, shell thickness, breaking strength, specific gravity, air cell, albumen height and weight, and yolk index. Albumen quality is influenced by genetic factors. (Johnson and Merritt, 2005)
1.4 JUSTIFICATION OF THE STUDY
This study was undertaken to provide information on storage period and influence of wonderful kola on egg quality parameters of Isa Brown Egg Layer Chickens. The problem has been to find a factor that is rapidly measured and associated with the difference in quality. (Jones et al., 2010)
A number of studies have been conducted concerning the effects of storage time on egg quality. However, the interaction of time and temperature is not fully known. As far as we know, no literature reported all these parameters together varying different seasons, storage conditions and laying hen strains (egg shell color).
1.5 GENERAL OBJECTIVES
The study therefore seeks to assess the effect of wonderful kola in the diet of Isa Brown pullet as a phyto-additive on egg quality and storage parameters (Temperature, pH, Time).
1.6 SPECIFIC OBJECTIVES
- To assess the proximate, minerals and phyto-constituents of wonderful kola seed which are beneficial in poultry for egg production.
- To determine the impact of different storage period on egg quality
- To determine the effect of wonderful kola on eggs after period of storage.