Problem of Egg Productivity in Hens and Its Early Prediction

Abstract

A b s t r a c tThe generalized processes of natural maturation of oocyte with egg yolk in the ovary, production of egg white and eggshell in the oviduct, as well as ovulation and laying cycle are under the genotype control. Besides, they are affected by the environment and regulated by neurohumoral (neurohormonal) system. All these factors determine ultimately the egg productivity in poultry. Thus, it is limited by time, required for the oocyte maturation and yolk synthesis, and also by the decreasing reproductive potency of hens and egg quality because of aging and/or influence of technological factors. Whatever it was, the observed phenotypic variability due to selection pressure and the applied intensive technologies in poultry indicates the physiological limits of productivity (i.e. egg-laying rate, egg weight and quality) to become wider in hens with intensive metabolism. In the modern egg hybrid crosses a daily ovulation occurs synchronously with a mature egg formation and laying during long productive usage. The egg laying chickens can be forecasted in the postembryonic ontogenesis by the number of large follicles which are maturing in the ovary, if 85-90 % egg productivity is reached within 5-6 weeks after the laying begins. The steady cycle of egg laying with small interval (1-2 days) is also of importance. Thus, the rapid formation of 5-6 follicles in the ovary coinciding with weekly maturation of the yolk in ovogenesis determines the biological potency of reproductive function in high-yield laying hens. The use of these parameters for assessing egg chicks and their offspring gives an opportunity to predict the high-producers in the early ontogenesis. It will speed up breeding to improve modern egg crosses, create new ones, and also to optimize the intensive technologies in poultry.Keywords: egg productivity, chicken genome, oocyte, ovary, ovogenesis, egg-laying, integrity, concept, prediction.Since 1950s due to long and intensive breeding and hybridization the annual egg productivity in hen crosses increased almost 2 times and amounts 320-330 in number and 60-65 g in an average weight compared to 55-60 g. The weight of shell and white of the eggs mostly increases, while the yolk weight in selected lines of egg crosses is stabilized at 16-17 g, being up to 18 g on average in hybrids (1). Hence, egg productivity almost reached the biological limits.Complicated processes of natural maturation of oocyte with the yolk in the ovaries, the egg white and shell formation in the oviduct, ovulation and oviposition are genetically based, neurohumorally regulated and depend on the environment. Therefore, egg production is limited by the time of an oocyte maturation and the yolk formation, on one side, and a reduced productivity and egg quality upon hen aging and(or) because of used poultry technologies, on the other side.Study of genome structure and functions in the hens with high egg production are being intensified resulting in developed and improved technologies for poultry breeding and commercial use. Thus, e...

Efficiency of Sales of Edible Eggs by Weight and Categories. Pricing Methodology

“…In modern economic conditions increasing the efficiency of production in poultry farming becomes not only the main direction of its development but also practically the only opportunity to further increase the production of eggs and poultry meat, and to increase the competitiveness and profitability of the industry [1][2][3][4]. The efficiency of the productive activity of poultry farms depends on a set of interrelated factors: housing conditions, productivity, livability and duration of productive use of poultry, product quality, feed and labor costs for production, market prices of products [5][6][7][8][9][10][11][12].…”

Structural features of the ovaries of texas quail in the experiment

“…The reproductive organs of ducks, turkeys, and chickens have been thoroughly studied, while the morphology of the sexual apparatus of quails has not been sufficiently examined. The structure and development of egg-forming organs in quails have not been studied enough, and the existing works in this area reveal only fragments of these aspects [13][14][15][16][17][18][19].…”