Comparison of egg hatchability and in vitro survival of goose embryos of various origins.

Hatchability of 69,324 fertilized eggs of White Italian geese from the WD1 maternal strain, selected for egg production, and of 25,226 eggs from the WD3 paternal strain, selected for weight gain, were compared. A significant difference was noted, but its magnitude varied during the reproduction season. Mean results for the WD1 strain (80.9%) were always higher (P < 0.01) than those of WD3 strain (75.8%). To determine the causes of this difference, goose eggs from WD1, WD3, and the Kuban (K) strain that demonstrate high reproductive performance (egg number, fertility, and hatchability) were incubated in a laboratory scale incubator. Embryonic mortality and egg weight loss during incubation were determined. Best hatchability (78.5%) was noted in eggs from K goose strain and the weight loss attained 10.9% of the initial egg weight, until Day 25 of incubation. With the higher egg weight loss in Strains WD1 (11.8%) and WD3 (13.2%), hatchability was diminished to 67.3 and 65.5%, respectively. Better hatchability resulted from lower mortality up to Day 6 of incubation and, especially, between Days 7 and 25 of incubation. The differences found in the egg weight losses and in embryonic mortality suggest a need for adjusting the incubation technique to the particular goose genotype. Embryo cultivation in vitro in plastic containers made the comparison of embryo survival possible, because the interaction of incubator microclimate by eggshell quality was eliminated. The results noted due to strain were ranked in the following order: K, WD1, and WD3. The experimental findings suggest that, apart from that of shell quality effect on various egg weight losses during incubation, there appear to be other factors that cause differences in hatchability of the goose strains studied.