This document summarizes research on on-farm hormonal oestrus synchronization and mass artificial insemination of cows for smallholders in Ethiopia. It finds that while a researcher-led approach showed promise, scaling required institutional changes. Working with regional partners to train staff, over 600,000 cows were synchronized and inseminated from 2011-2015 across four regions. New technologies like progesterone tests helped with estrus detection and pregnancy diagnosis. The Ethiopian government's Livestock Master Plan now aims to increase crossbred cows to 5 million in 5 years to boost milk production and incomes.