Chromosome C-band polymorphism in relation to fertility in boars of the Duroc breed

In a study of the variation of fertility in boars of the Duroc breed from Danish AI stations, chromosome investigation has been conducted on 11 boars with high and 11 with low fertility, respectively, out of a total of 98 boars having normal semen quality according to AI standards. All 22 boars had the normal chromosome number. C-band polymorphism at chromosome 16 and 17 was more frequent in the low fertility boars compared with high fertile ones (P less than 0.01), and on average a C-band polymorphic boar sired 0.99 piglet less per litter than a non-polymorphic. More investigations are warranted before application of the results can be brought into practical swine breeding.