| Number of Mares Reported Bred to Thoroughbred Stallions in 2021 | |||||
| A B C D E F G H I J K L M N O P Q R S T U V W X Y Z | |||||
| Stallion | Mares Bred | State | |||
| R F F Golden Time | 1 | ON | |||
| R H F Rockwell | 3 | TN | |||
| Rack Em Up | 6 | ND | |||
| Rainbow Heir | 8 | MD | |||
| Raised a Secret | 13 | WA | |||
| Raising the Flag | 4 | OK | |||
| Raison d'Etat | 6 | KY | |||
| Ralis | 12 | BC | |||
| Rampant Rhythm | 1 | IL | |||
| Ransom the Moon | 14 | KY | |||
| Rattlesnake Bridge | 6 | FL | |||
| Razor | 1 | KY | |||
| Rda Oro Blanco | 1 | CA | |||
| Ready Intaglio | 5 | AB | |||
| Ready's Image | 15 | IN | |||
| Real Quiet Cat | 1 | TX | |||
| Real Solution | 8 | KY | |||
| Red Hot Warrior | 13 | PR | |||
| Redbulletexpress | 2 | FL | |||
| Redeemed | 14 | TX | |||
| Redesdale | 19 | NY | |||
| Redirect | 10 | WV | |||
| Regalo Del Oro | 1 | AB | |||
| Reload | 90 | ON | |||
| Remembering Rita | 10 | NE | |||
| Requite | 6 | LA | |||
| Revolving | 3 | TX | |||
| Revved Up | 21 | OK | |||
| Rff Golden Justice | 2 | CA | |||
| Richard's Kid | 30 | CA | |||
| Ride On Curlin | 11 | FL | |||
| Ride the Times | 1 | TX | |||
| Right Rigger | 8 | NM | |||
| Rimrod | 1 | PA | |||
| Rise Up | 12 | OR | |||
| Rivers Run Deep | 18 | OH | |||
| Road Ruler | 10 | IL | |||
| Robie the Cat | 1 | OH | |||
| Rock Hard City | 2 | NM | |||
| Rocky Bar | 6 | AZ | |||
| Rogueish | 72 | FL | |||
| Roll Hennessy Roll | 1 | NM | |||
| Roman Gladiator | 10 | CO | |||
| Roman Scout | 7 | PR | |||
| Romeo Lima | 2 | IL | |||
| Rousing Sermon | 13 | CA | |||
| Rowayton | 44 | PA | |||
| Rule by Night | 4 | NM | |||
| Ruler's Court | 4 | LA | |||
| Rumpus Cat | 11 | CA | |||
| Run It | 3 | CA | |||
| Run Production | 7 | LA | |||
| Runaway Ghost | 48 | NM | |||
| Runhappy | 56 | KY | |||
| Running Tap | 7 | WA | |||
| Runnintothealter | 1 | PA | |||