THE BREEDING POTENTIAL OF FULL SISTERS IN THE DOMESTIC FOWL

The breeding potential of low and high egg producing full sisters was determined with Barred Plymouth Rocks. The average egg production for each group of full sister dams was the dividing line between low and high dams. All the individuals in a group of full sisters were mated to the same male, and the progeny from all groups were randomized among the laying pens.The average yearly egg production of the progeny of low and high dams was 220.5 and 227.5 eggs respectively. The difference of 7 eggs in favour of the progeny of high dams was highly significant.Family selection would be less effective than individual selection in the population under consideration. Most progress would likely be made where selection is based on individual merit plus some attention to the average merit of the family.