| GENERATION 1 | GENERATION 2 | GENERATION 3 | GENERATION 4 |
|---|---|---|---|
| ORMEROD'S IOWA CHALLENGER | UNKNOWN | UNKNOWN | |
| UNKNOWN | |||
| UNKNOWN | UNKNOWN | ||
| UNKNOWN | |||
| UNKNOWN | UNKNOWN | ||
| UNKNOWN | |||
| UNKNOWN | UNKNOWN | ||
| UNKNOWN | |||
| ORMEROD'S WHITE HEAD | UNKNOWN | UNKNOWN | |
| UNKNOWN | |||
| UNKNOWN | UNKNOWN | ||
| UNKNOWN | |||
| UNKNOWN | UNKNOWN | ||
| UNKNOWN | |||
| UNKNOWN | UNKNOWN | ||
| UNKNOWN |