Selection for increased incidence of double‐yolked eggs in white leghorn chickens

Abstract

1. Eleven generations of selection on two White Leghorn lines resulted in birds which, on the average, laid at least 30 double‐yolked eggs to 40 weeks of age. 2. The total number of yolks laid to 40 weeks was comparable with that of a control line selected for high egg number. 3. At peak production an F1 cross of the two inbred lines laid 140 yolks per hundred hens per day. 4. Double‐yolk selected lines when crossed produced hens with a 20% increased body weight. 5. By the 10th and 11th generations the incidence of eggs with three or four yolks was increasing.