Broiler chicken (Gallus gallus domesticus), are a gallinaceous domesticated fowl bred and raised specifically for meat production. Broiler production is the largest agricultural revenue generator in the world (FAO, 2017). Broiler birds under intensive production system mature between 6-7 weeks of production. The rapid growth of broiler demands that they should be supplied with high quality diets which satisfy both their nutritional needs as well as ensuring high profits (Onyimonyi et al., 2009). Increase in broiler production has the tendency of reducing the gap of animal protein inadequacy in the diet of most Nigerian which has been a source of major concern to animal nutritionist (Adeyemo et al., 2010).
The demand for protein, most especially in developing countries like Nigeria is on a daily increase; due to the rise in population since protein from animal sources are rich in the essential amino acids, minerals and vitamins the body requires (Odunsi et al., 1999). Protein is a vital nutrient for poultry and all other classes of animals. In virtue of its amino acid constituents, protein plays a significant role in growth, egg production, immunity, adaptation to the environment, and in many other biological functions. Optimisation of protein supply requires a thorough understanding of the protein requirements of chickens and manipulation of protein supply to better suit various environmental conditions, health status of birds, and economic feeding (Fasuyi et al., 2007).
Pawpaw is a fruit which has high amounts of vitamin C and minerals such as potassium, magnesium, iron and sodium. The fruit is also a good source of essential amino acids and contain significant amounts of riboflavin, niacin, phosphorus and zinc. The amounts of these nutrients are greater than or about the same as those found in bananas, apples or oranges. Papaya is famous for its nutrition potential as well as whole plant is popular for its medicinal properties. The skin of unripe fruit is smooth and green. When ripe, the skin turns yellow or orange. The flesh of ripe fruit is yellow, orange or red in colour. Papaya seeds are in the ovarian cavity, which is larger in female fruit than hermaphrodite. The seeds are small and dark brown or black with translucent sarcotesta mucilaginous (Ahmad et al., 2011).
Papaya enzyme (papain) can be classified as proteolytic enzyme, meaning it easily digest protein. It is reported to provide a wide variety of health benefits. The high increase in protein degradation is owing to the presence of papain in C. Papaya. Whereas, catalytic activity of papain involves hydrolysis of protein with broad specificity for peptide bonds. The possibilities of supplementing commercial enzymes in monogastric diets has provided nutritionists with a very important tool to improve feed digestibility, reduce environmental contamination and lower feed cost. Thus allowing for more flexibility in diet formulation. This reflects a better flock performance, increase the efficiency of digestion which will definitely improve the carcass and organs characteristics of the broiler chickens and also improved bird health, which in turn, has a positive influence on total production costs (Esonu et al., 2004). In order to enhance the availability of this animal protein year round, the use of enzymes is employed in poultry industry to maximally utilize the feed especially those having fibre content in order to achieve this goal. The major aim of this research is to study the effect of varying dietary protein levels with or without papaya enzyme on carcass and organ characteristics of broiler chickens.
1.2 Justification of the study
The need to assess the effect of varying dietary protein levels with or without papaya enzyme on the carcass and organ characteristics of broiler chickens is of great importance, because enzyme is a protein catalyst and helps animal in feed digestion. However, the addition of enzymes in animals feed will improve the nutritional value of feed ingredients, thereby increasing the efficiency of digestion which later result to improvement of the carcass and organs characteristics of the broiler chickens.
1.3 Objective of the Study
1.3.1 General Objective
To determine the supplement effect of papaya enzyme on carcass and organ characteristics of broiler chickens.
1.3.2 Specific Objectives
- To determine the carcass cut up parts of broiler chicken fed varying protein levels with or without papain enzyme.
- To assess the organ weight of broiler chicken fed varying protein levels with or without papain enzyme.
- To compare the intestinal measurements of broiler chicken fed varying protein levels with or without papain enzyme.