|French, N -|
|Nicholson, D -|
Submitted to: International Poultry Scientific Forum
Publication Type: Abstract Only
Publication Acceptance Date: January 25, 2010
Publication Date: N/A
Technical Abstract: Cold egg storage is a common practice prior to incubation in the broiler industry. However, cold storage longer than 10 days is associated with an increase in early embryo mortality. We were interested in determining the developmental stages of early dead embryos after prolonged egg storage and incubation for 8 days in broiler breeder Lines A and B. Eggs from A and B were stored for 27 days at 16.1-16.6C and 70% humidity. After 3 hr of room temperature equilibration the eggs were incubated for 8-days. After candling, only clear eggs and eggs with blood formation were opened and either categorized as unfertilized or as follows: pre-blood; blood; or membranous. We determined that the membranes observed in both lines were cellular and assumed they originated from the extra-embryonic membranes. In Line A, of the 182 eggs candled 15 (8%) had viable embryos and 167 (92%) were either unfertilized or early deads. After breaking out the latter group, we observed the following: infertiles, 20 (12%); pre-blood, 79 (48%); blood, 19 (11%); and membranous, 48 (29%). In Line B, of the 187 eggs candled 72 (38.5%) had viable embryos and 115 (61.5%) were either unfertilized or early deads. After breaking out the later group, we observed the following: infertile, 19 (17.6%); pre-blood, 14 (13.0%); blood, 40 (37.0%); and membranous, 35 (32.4%). To summarize, Line B embryos survived storage more successfully than Line A (38% vs 12% viable embryos, respectively). In Line A, 76% (pre-blood plus membranous categories) of the embryos failed to develop beyond 24-30 hr of incubation. In contrast, only 45% of Line B failed to reach blood formation. We suggest that the biological basis of early embryo mortality following prolonged cold egg storage may be line specific. Identification of these differences may lead to a better understanding on how to address early embryonic mortality associated with cold egg storage in broilers.