In this article, Cahyadi et al. present the findings of a study on herd dynamics of smallholder cattle producers in the two major agro-ecosystems (irrigated lowland and rain-fed upland) in East Java. The research aims to better understand the capacity of smallholder cattle producers in order to increase their production and income in line with government targets. A total of 184 farmers participated in the study in 2010. Their cattle were monitored on a monthly basis to record vital statistics, as well as transfer and sales-related data. The findings reveal that the number of cattle in the lowland site increased by 7 per cent and decreased by 2 per cent in the upland site—levels that do not support ambitious growth targets. In conclusion, the authors assert that reproductive performance, cattle numbers and growth rates could improve with greater use of natural mating, better coordination of mating with available feed supplies, and targeted use of legume-feeds. However, they acknowledge it may be difficult to achieve these productivity gains given the resource constraints and market signals experienced by farmers.