The Effects of Current Egg Production, Time in Production, Age of Pullet, and Inbreeding on Hatchability and Hatching Time

DATA have previously been presented by Bohren, Crittenden and King (1961), and Crittenden and Bohren (1961), showing the heritabilities and interrelationships between measures of hatch of fertile eggs at specific incubation periods, and hatching time, egg weight and holding time. The present study was undertaken to investigate two genetically influenced variables, egg production during each of three two-week saving periods (P) and weeks in production before the average time when the eggs were set (T), one completely environmental variable, defined as the weekly age group in which the pullet was hatched (A) and the inbreeding coefficient for the pullet (I) and their relationship to the hatchability traits X1, X2, X3 and X4, previously defined as the percent of fertile eggs hatched for each hen, from the first hatching period through the period when approximately 30, 50, 70 and 100 percent of all chicks were hatched, respectively. The purpose was to . . .