Erratic Oviposition and Egg Defects in Broiler-type Pullets

Abstract

Abstract THE females which produce chicks for broiler production have changed greatly during the past 15 to 20 years. Broiler chickens were twice as large at 8 weeks of age in 1965 as those of the same age in 1952 (Maine Broiler Test Reports, 1952–1965). The mothers of broiler chicks now reach an adult body weight of 3 1/2 to 4 kilograms. During this same period (1950–1965), egg-type females have been reduced from about 2.2 kilograms adult body weight to approximately 1.9 kilograms. This dramatic difference in body size between broiler- and egg-type females has been accompanied by many other changes in appearance and behavioral activity. External and behavioral differences are more readily observable than those which are internal and physiological The following report records observations concerning non-rhythmic laying patterns and the high incidence of egg defects in these large-bodied broiler strains. Irregularities of oviposition time and the accompanying defects appear . . .