The effects of two Australian strains of infectious bronchitis virus (IBV-T and N1/88) on the internal and external quality of eggs were studied in unvaccinated Isa Brown hens in full lay. Overall, there was no decline in egg production in either of the infected groups. However, there were some long-lasting negative effects on the egg internal quality of T-infected hens. Negative effects on internal quality in the N1/88-infected group were relatively short term. Yolk colour score was lower only in T-infected hens. Egg shell quality was affected only in terms of loss of egg shell colour. IBV infection resulted in paler egg shells in both the infected groups. Paler egg shellsmaynot be regarded well by consumers. The egg shape index was lower in both infected groups.
Chousalkar, K., & Roberts, J. (2009). Effects of Australian strains of infectious bronchitis virus on internal and external quality of hen eggs. Animal Production Science, 49(2), 162-169. https://doi.org/10.1071/EA08167