Effect of Eggshell Abnormalities on Table Egg Quality during Storage24 October 2014
Eggshell apex abnormalities were found by researchers in Brazil to increase egg weight loss during storage and reduce shell strength but the internal quality of these egg was no different from those of normal shape.
Mycoplasma synoviae infection of hens has been associated with problems of eggshell quality called eggshell apex abnormalities (EAA), according to M.D.M. Brandão of the Federal University of Fluminense and co-authors there and at the Biological Institute in Bastos.
In the current issue of Poultry Science, they report that little is known about the quality of EAA eggs from a commercial point of view, especially during their storage.
Their study aimed to examine the differences between EAA and normal eggs during storage under controlled conditions in two seasons – summer and winter – by comparing internal and external quality parameters.
In a conventional egg production farm with white laying hens of varying ages in the city of Bastos in the state of São Paulo, 232 eggs were used in the summer season and 400 eggs in the winter season.
Half of the eggs had EAA, and the other half were considered normal eggs for each season.
The eggs were analysed at two, seven, 14, 21 and 28 days after being laid and stored from 24.6 to 25.8°C in summer and from 24 to 25°C in winter.
There was no difference (P>0.05) in the average egg weight between EAA and normal eggs at any studied time point but in both seasons, the weight loss in EAA eggs was higher than in normal eggs.
The losses in Haugh unit scores from the first to the last measurements were approximately 40 per cent, regardless of egg type or season of production.
In comparing eggshell thickness, only the apices of the EAA eggs were thinner (P<0.0001) than normal eggs in the summer but in the winter, the EAA egg apices (P<0.0001) and sides (P=0.03) were both thinner.
The presence of EAA did not affect the eggshell weight (P>0.05) or eggshell percentage (P>0.05).
Strength of the eggshell of the EAA eggs was lower (P<0.0001) than normal eggs in both the summer (16.57 per cent) and winter (19.86 per cent).
Brandão and co-authors concluded that the presence of EAA did not affect the internal quality of the egg but was related to a greater loss of external quality and weight during storage.
Brandão M.D.M., F.F. Santos, L.S. Machado, M.S. Verinaud, J.M. Oliveira, N.M. Soares, E.R. Nascimento and V.L.A. Pereira. 2014. The effect of eggshell apex abnormalities on table egg quality during storage in 2 seasons of the year. Poultry Science. 93:2657-2662. doi: 10.3382/ps.2014-03991