It is better to avoid eggs consumption during treatment and withdrawal periods, according to Huwaida E.E. Malik of the University of Khartoum and co-authors there and the University of Gezira.

Their conclusion was drawn from a study, published in the current issue of International Journal of Poultry Science, which was conducted to detect the effects of a sulphonamide drug on table egg quality and to determine the withdrawal time after which eggs are save for human consumption. The sulphonamide (Coccidiofan) was administered to 36 layer hens, at a dose of 1g per litre in the drinking water for three consecutive days.

Traits studied were egg quality traits and the presence of drug residues.

Results showed that treatments were significantly (P<0.05) different in eggshell weight and eggshell thickness; estimates were 6.61±0.10, 6.61±0.10 and 7.09±0.23 for the first trait and 0.22±0.01, 0.26±0.012 and 0.28±0.012 for the second trait in the control, treated and withdrawal groups respectively.

For internal egg traits, yolk height, yolk width and yolk index were significantly (P<0.05) affected. The control group recorded 16.02±0.37, 34.79±0.28 and 46.19±1.30 for the three traits, treated group estimated 15.64±0.19, 38.11±0.30 and 39.69±0.55 while the group in the withdrawal period recorded 15.10±0.21, 39.69±0.55 and 42.47±0.62, respectively.

The percentages of mottled, blood spotted, misshaped and rough shelled eggs were high in the layers in the withdrawal period compared to layers in the control group which reported zero per cent for all traits and layers in treated group which recorded lower percentages than those in the withdrawal period.

Results also showed that the drug residues appeared in eggs in second day and third of treatment at 1.80 level and the level increased to 2.22 in the first and second day of the withdrawal period then declined to reach 0.22 on the fifth day of the withdrawal period.

Reference

^{Malik H.E.E., J.E. Omer and K.M. Elamin. 2013. Effect of sulfanomides residues on egg quality traits. International Journal of Poultry Science 12 (5): 312-317.}