The notes on regarding Milan Mill states that her passing on of the large heart gene is why Mill Reef turned out to be such a good sire found in the pedigree of many stakes winning horses.

My first thought was that I often find Mill Reef in pedigrees through his son Shirley Heights and he could not have inherited the large heart gene from Milan Mill.  On checking I find that 45% of Mill Reef's stakes winning descendants are through Shirley Heights which is high enough for me to think that Milan Mill large heart is not as important as people would want us to believe. 

Even looking at Mill Reef's Group 1 winning offspring you would have to conclude that he was a better sire of colts (not getting that Milan Mill large heart gene) than fillies. His sons Shirley Heights, Reference Point, Doyoun, Glint Of Gold, Lashkari, Acamas, Creator, Ibn Bey, King Of Clubs, Marooned, Pas De Seul and Wassl to my mind beat the two daughters Fairy Footsteps and Paris Royal.  Then what of these two Gr1 winning large-heart carrying daughters. Paris Royal is yet to show up in any group winning animal and Fairy Footsteps' is only shows up in group 1 winners as the second dam of Desert Prince.

On to the second generation where we find 34 group one winners. 23 through sons (not having the Milan Mill large-heart gene) and 11 through daughters.  Last Tycoon and Pentire are possibly the best two that could inherit from Milan Mill.  Daylami, Kalanisi, Darshaan, Slip Anchor could not have inherited.

In the third generation 56 could not inherit.  A further 42 were by sires or dams that could have inherited a Milan Mill large-heart gene.  Most of the offspring could not have though.  For instance Last Tycoon could have inherited Milan Mill's large heart gene.  He could not pass this on to his sons like Marju, O'Reilly etc. 

There are 82 group 1 winning descendants in the 4th generation.  69 are through just two Mill Reef sources.  Through son Shirley Heights accounts for 48.  Through daughter Mill Princess via Last Tycoon accounts for 21.  Marju, O'Reilly and Bigstone account for 11 and being sons of Last Tycoon they can't have inherited that Milan Mill large-heart gene.  There are just 8 through daughters.

However, to test that Milan Mill large heart gene we should not focus solely through her best son. Ask oneself what group 1 winners there are that have Milan Mill on the tail female line?  That is where we know the large-heart gene must be inherited.  Let us see .. there's Mill Reef. 

At a stretch we could include Fuji Kiseki (Jpn) and Zurburan (Ind)   The trouble with these two is that we don't know how good you needed to be in the mid 90's in the land of protectionism or to win the Indian St. Leger. Zurbaran never even placed from 3 races in Dubai. 

We can't blame the stallions that these Milan Mill daughters, grand-daughters and great-grand daughters have been seeing.  In the main they are top class. Fuji Kiseki, for example, is by Sunday Silence out of Millracer (by Le Fabuleux) who is out of a In Reality mare who is out of a Cornish Prince mare. 

On the plus side although there have not been too many Gr1 types there have been 10% stakes winners to foals with Milan Mill on the tail so that is not be be sneezed at.

The question is simply whether this is a success rate due to all those top class stallions or Milan Mill's large heart gene? 

Adrian Parry Copyright 2006