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Abstract
INTRODUCTION
Flock uniformity within male and female populations is the number one goal to achieving maximum performance for broilers and egg production and seems to be a short way to supply the market with necessary meat chickens and eggs.
Average body weight and body weight uniformity are inseparable topics. Uniform flocks with the proper weight have several advantages: (a) birds are managed in large groups and are exposed to management changes (lighting, feed and housing) at the same time, whether they are physiologically ready or not, (b) are more efficient, (c) have higher peak production and (d) come closest to expressing their full genetic potential.
Traditionally, the emphasis on uniformity of broiler chicks has been dictated by the last part of the production chain. The automated slaughtering process demands uniformity of product entering the processing plant. Often, achieving uniformity is regarded as the broiler farmer’s job and indeed, uniformity of broilers at slaughter weight can be greatly influenced by what happens on the broiler farm. As chick uniformity is unlikely to increase during the production process, a key prerequisite to a uniform end product is uniformity in the day olds. Day-old flocks showing poor uniformity are impossible to manage properly, which will result in lower growth, increased feed conversion and higher mortality during the first week (Van de Ven, 2005).
As the same, when the pullet is grown improperly during the early growing period, it will be difficult to improve the pullet during the remaining growing period.
Some confusion arises when it comes to the question of measuring uniformity. Poultry growers generally assess the uniformity of a flock by eye. Information regarding practical standards for measuring the uniformity was defined by (North, 1978a); according to him uniformity is measured as the percent of the birds that weigh within ± 10% of the average flock weight. Flocks in which less than 70% of the birds meet these criteria are considered no uniform.
Genetics is a good starting point for achieving uniformity. So, selection for uniformity is a method to increasing it in a population. Good management can also result in more uniformity.
Generally, no attempts were done to improve uniformity in our local strains for body weight and age at sexual maturity so our present study aimed to increase the uniformity of Alexandria strain as well as the effect of increasing uniformity on productive and reproductive performance.