Loyd "Boo" Gentry, Jr. (born August 29, 1925 in Kenton County, Kentucky) is an American horse trainer.
He was the son of jockey and trainer, Loyd Gentry, Sr., who trained for the prominent Canadian horseman Harry C. Hatch and for whom he conditioned the winner of the 1941 King's Plate, Canada's most prestigious race. Loyd Jr. was also the nephew of Olin B. Gentry. He competed mainly at race tracks in New York, South Florida, Kentucky, and Illinois. Gentry, Jr. trained the 1967 Kentucky Derby winner, Darby Dan Farm's, Proud Clarion, ridden by Bobby Ussery. Proud Clarion finished 3rd in the 1967 Preakness, behind Damascus and In Reality. In addition to Proud Clarion, Gentry also had three other horses that ran in the Kentucky Derby. In 1952, Milton Shagrin's Shag Tails, ridden by John Nazareth, finished 13th. In 1955, Racing Fool, ridden by Henry Moreno, finished 4th, and Flying Fury, ridden by Conn McCreary, 6th. Both horses were owned by Harry F. Guggenheim's Cain Hoy Stable.
In 1966, Gentry trained Darby Dan Farm's Graustark, winner of the 1965 Arch Ward Memorial at Arlington Park and the 1966 Bahamas Stakes at Hialeah Park. After Buckpasser suffered a quarter crack, Graustark became widely favored to win the Kentucky Derby that year. Because Graustark had never raced over 7 furlongs, it was decided, in spite of a slightly infected left front hoof, to run him in the 9 furlong Blue Grass Stakes as a prep for the 1966 Kentucky Derby. Graustark was beaten by a nose by Abe's Hope after suffering a career ending injury.
Gentry twice won the Kentucky Oaks with Lalun (1955) and Hail to Patsy (1969).
| Year | Name | Jockey | Owner | Fame |
|---|---|---|---|---|
| 1954 | Flying Fury | Henry Moreno | Cain Hoy Stable | Champagne Stakes winner |
| 1955 | Lalun | Henry Moreno | Cain Hoy Stable | Beldame Stakes winner |
| 1955 | Lalun | Henry Moreno | Cain Hoy Stable | Kentucky Oaks winner |
| 1955 | Racing Fool | Henry Moreno | Cain Hoy Stable | Bluegrass Stakes winner |
| 1955 | Racing Fool | Johnny Adams | Cain Hoy Stables | Forerunner Stakes winner |
| 1964 | Umbrella Fella | John Nazareth | Ford Stables | Lane's End Breeders' Futurity winner |
| 1969 | Hail To Patsy | Dave Kassen | Walter Kitchen | Kentucky Oaks winner |
| 1970 | Supreme Quality | Dave Kassen | Walter Kitchen | Forerunner Stakes winner |