He is now renewing that call, and as he points out in a letter sent widely to British breeders today, and detailed on this page, there are already numerous artificial technologies - he names nine, including "[application of] Regu-Mate and other synthetic progestagens to mimic dioestrus
, suppress oestrous behaviour, induce follicular development and supplement the mare's own progesterone levels during pregnancy", and "immunisation with stallion white blood cells to prevent repeated early abortion in immunologically deficient mares" - used to help conception along.
While trying to find what causes a mare's uterus to recognise that it is pregnant, they infused a group of mares with a preparation containing estrogen in an oil solution, and found that nearly all the mares went into dioestrus, or a period of not cycling.
To their surprise, 90 per cent of the mares again went into dioestrus.
He adds: "The bottom line is, it is very easy to kick a mare into prolonged dioestrus.