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

Abstract

Eleven generations of selection on 2 White Leghorn lines resulted in birds which, on the average, laid at least 30 double-yolked eggs to 40 wk of age. The total number of yolks laid to 40 wk was comparable with that of a control line selected for high egg number. At peak production an F1 cross of the 2 inbred lines laid 140 yolks/100 hens per day. Double-yolk selected lines when crossed produced hens with a 20% increased body weight. By the 10th and 11th generations the incidence of eggs with 3 or 4 yolks was increasing.