Search

DESPITE the precautions undertaken to secure better hatchability, some eggs fail to hatch. Such eggs represent a great loss for both hatchery men and breeders. This experiment was done to study embryonic mortality and malpositions in Fayoumi. REVIEW OF LITERATURE A. Embryonic Mortality. Embryonic mortality occurs at any time from fertilization up to the time of hatching. Payne (1919) found that there was two peaks of embryonic mortality and reported that 65 percent of all embryonic mortality occurs between the fourth and the sixth day of incubation. In contrast, Byerly (1930) found that the first peak occurred on the third day of incubation. Byerly et al. (1934) reported that there was a minor peak at about the seventh day of incubation. Later on, they found another peak in the middle of the incubation period, which was related to nutritional deficiencies in the diet consumed by the flock. They also reported …

INTRODUCTION ONE of the main suggestions to solve the problem of the shortage of both eggs and meat in Egypt is to import and adapt the high yielding foreign breeds of poultry. The author follows up his study of three commercial strains imported from Holland and the native strain known as Fayoumi. Amer (1956) compared the foreign breeds and Fayoumi with respect to fertility, hatchability, body weight and body measurements. Later on, Amer (1964), made a comparison between the previous breeds and the local strain with respect to annual egg production and mode of laying. This paper deals with the study of age at sexual maturity, body weight at sexual maturity and egg size in the standard breeds and Fayoumi. REVIEW OF LITERATURE Sexual Maturity: Byerly and Knox (1946) reported that pullets of later hatches laid their first egg at older ages than those of earlier hatches. They added that…

INTRODUCTION SELECTION is considered to be the best tool for genetic improvement in a given population. Heritability of a character is an important factor affecting genetic improvement. In a previous paper, Issawi et al. (1963) studied heritability of fertility and hatchability in Fayoumi. The present paper deals with the study of heritability of body weight in Fayoumi. REVIEW OF LITERATURE Many investigators estimated heritability of body weight in chickens. Spector (1956) summarized the different estimates of this character and concluded that it was highly heritable. In Single Comb White Leghorn, Lerner et al. (1949) stated that heritability of body weight at twelve weeks of age was 0.475, and 0.597 and 0.506 on the basis of the contribution of sire, dam, and both, respectively. Fagan (1949), reported similar figures for heritability of body weight at twelve weeks of age, being in the range from 0.35–0.50. El-Ibiary and Shaffner (1951), reported…