giving a
persistent wide range of variation in each generation.
There is, thus, evidence of a great deal of useable
variation still existing within modern breeds of chickens
(Granevitze et al 2007; Hill 2010; Weiner & Wilkinson
2011), but in order to maximise the potential of any
multi-trait breeding programme for broilers, it may be
valuable to utilise as many different sources of genetic
variation as possible, such as:
(i) Using a wide range of breeds from different parts of the
world to reintroduce ‘missing alleles’ that may have been
lost in the course of domestication or more recent selection
for particular traits.