Hen Age Relationship with Embryonic Mortality and Fertility in Commercial Turkeys

SUMMARY The purpose of this study was to examine embryonic mortality in turkey eggs from hens of two ages and to report values that minimize the error of wrongly distinguishing between early embryonic mortality (EEM, Days 1 to 7 of incubation) and unfertilized eggs. Three hatch residue breakouts were performed at each of two commercial turkey hatcheries for a total of six hatches. Nicholas Large White turkey eggs from two hen age groups (32 to 35 and 44 to 50 wk of age) were set in the same incubator that operated under the incubation profile of each hatchery. The EEM was significantly greater (P ≤ 0.0001) in younger hens when compared to older hens. This was true for mortality prior to blood formation and mortality following blood formation. Hatchability, percentage internal pips, and live pips were not different between the two hen ages. Prepip mortality and percentage dead pips were significantly (P ≤ 0.0001) greater in older flocks. Fertility and EEM occurring after blood formation were negatively correlated in younger hens, whereas mortality occurring before blood formation did not correlate with fertility in eggs from either hen age. Eggs from young hens tended to experience embryonic mortality earlier in incubation than eggs from older hens. The results suggest that hen age influences embryonic mortality in modern commercial turkeys and could be used as an experimental model for further study of embryonic mortality.