 this is the third international meeting dealing with major genes in small ruminants . 
 the first was held in armidale ( nsw , australia ) in 1980 , just after the discovery of the booroola gene by b. bindon and l. piper . 
 the discovery of a gene having such a large effect on ovulation rate and prolificacy in sheep was totally unsuspected at this time and a number of research teams all over the world concentrated their efforts to study its effects and identify the causal mutation . 
 about 20 years were finally needed to obtain this information , which opened a new approach to the physiological regulation of reproduction.the second meeting was organised in 1990 in toulouse along the same lines . 
 although its main concern was the booroola gene , other major genes influencing ovulation in sheep were also considered . 
 indeed , an increasing amount of evidence demonstrated that , on the contrary to the current opinion in quantitative genetics laboratories before 1980 , prolificacy is not always controlled by a very large number of genes each exhibiting a very small effect , but may also be influenced by genes with large effects , generalising the booroola situation to other populations.since then , mixed inheritance was also found for other production traits such as body conformation , seasonality or milk composition . however , the major evolution has been the inexpensive large - scale access to molecular genetic information , using pcr , microsatellites and snp technologies . 
 qtl detection experiments are performed in all domestic species , including sheep and goats , and the identification of genes having an average effect on the performance trait variability is now possible . 
 the utilisation of these polymorphisms should also be a great help for a better management of populations , either through the selection of breeders or through the preservation of genetic diversity.this third meeting on major genes and qtl in sheep and goats was a unique occasion for the researchers involved in this area of animal science to present their latest results , exchange their experiences and progress in the organisation of scientific co - operation . 