Male animals used to produce large numbers of offspring are called "popular sires". They are one of the biggest contributors to a reduction in genetic diversity, an increase in inbreeding and more occurrences of genetic diseases within a breed. Breeders should avoid using known popular sires but use a wider variety of males. Wikipedia - Popular Sire Effect
Please note: Not all sires listed in this statistic are actually to be classified as "popular sires", but they are those animals which have the most offspring in our database for the corresponding decade.