2. Selected and control lines were maintained within each strain.
3. After three generations of selection, egg shell deformation was reduced in the M selected line as compared to its control counterpart but this change in deformation was not accompanied by a reduction in egg breakage; however, no reduction in deformation or egg breakage was achieved in the H selected line.
4. Crossing the M and H strains resulted in a reduction of egg breakage in the crosses as compared to the average breakage of the parental strains, suggesting the potential of utilising strain crosses to reduce the incidence of egg shell breakage. 相似文献