Submitted to: Applied Poultry Research
Publication Type: Peer reviewed journal
Publication Acceptance Date: 8/28/2002
Publication Date: 12/31/2002
Citation: Bakst, M.R. Using non-settable eggs to evaluate hen fertility. Applied Poultry Research. 11:402-405, 2002. Interpretive Summary: Performing break-outs, cracking open the egg and visually identifying whether it was fertilized or not, of fresh eggs allows the turkey egg producers to determine quickly if there is a fertility problem in a flock. If fertility is low, then immediate remedial action can be performed at the hen farm minimizing production losses. Considering that the cost of producing one fertile egg is about $0.55, we examined the possibility of using cull eggs, eggs that could not be placed in the incubator due to shell damage, as a source of eggs for breakouts. We found that cull eggs could be used for break-outs, that their fertility is nearly the same as eggs for incubation, and that they can be used in an evaluation procedure which shows the rate of sperm penetrating the ovum at fertilization. It was concluded that cull eggs could be used to get an estimate of the true fertility of a flock.
Technical Abstract: The use of nonsettable eggs (checked, cracked, membranous, soft shell) to perform fresh egg breakouts to estimate true fertility and to assess the rate of sperm penetration of the perivitelline layer overlying the germinal disc was evaluated. Germinal discs and the perivitelline layer overlying the germinal disc were accessible for assessments. The stage of blastodermal development positively correlated (r = 0.65, P < 0.0001) with eggshell thickness. It was also determined that the perivitelline layer of nonsettable eggs could be isolated and stained to determine the presence or absence of sperm holes. True fertility in nonsettable eggs and settable eggs was 93% and 95%, respectively. It was concluded that nonsettable eggs could be used to get an estimate of the true fertility of a flock.