Growth characteristics including body weight, height, and average daily gain were measured between birth and 18 months of age in Thoroughbred horses born and raised on commercial stud farms in Australia, New Zealand, Kentucky, England, and India during the years 1996 to 2005.
Australian and Kentucky foals were heavier at 7 days of age than those born in the other countries, with Indian foals being lightest. Body weight did not differ between Australian, New Zealand, and Kentucky Thoroughbreds between 1 and 18 months, but Australian and New Zealand yearlings tended to be heavier than the other populations between 12 and 18 months.
This report of KER's 2006 research was published in Proceedings of the Australasian Equine Science Symposium.
Read the entire research paper, titled Body Weight and Growth Rates in Australian Thoroughbreds Compared with Thoroughbreds in Kentucky, England, New Zealand and India.