Researchers studied red junglefowl (the wild ancestor of the domestic chicken) in a collaborative project with the University of Oxford, Stockholm University and Linkoping University.
This is down to 'cryptic female choice' - where an internal mechanism in their reproductive tract favours the sperm from males that are most genetically different to them.
The genes in question (Major Histocompatibility Complex; MHC) play a key role in detecting and fighting infections. By biasing fertilisation in favour of MHC-dissimilar males, females increase the diversity of MHC within their offspring, providing them with better disease resistance.
Prof David S Richardson, from UEA's school of Biological Sciences, said that their research has shown that the females don't need to choose between males to produce the most healthy offspring.
He said that rather by mating with multiple males, they allow their internal choice mechanism to favour the most genetically different sperm.
The research investigated both experimentally controlled natural matings and artificial inseminations and found that the effect observed in natural matings was lost during artificial insemination.
Richardson added that to optimise the quality of offspring produced in breeding programs we may need to make sure that females mate with multiple males and that they avoid artificial insemination, which could lead to the genetic health of bred stocks being weaker.
The study has been published in the journal Proceedings of the Royal Society B.
--ANI (Posted on 04-09-2013)