The existing Andean dairy production patterns are scarcely known and yet they play a major role in the household food security of many families. This study examines the consistency of forage management through the monitoring of 8 dairy farmers of a community living in the harsh conditions of the dry Peruvian Andes and the analysis of their production practices. The Sinto farmers are able to produce milk throughout the year despite the very dry climatic conditions by adjusting cattle groups, grazing rotationaly on irrigated alfalfa fields, farming large rangelands zones and exchanging standing forage with other farmers. Although the milk production per cow is low, the milk yield per hectare of alfalfa field is relatively high. This can be interpreted both as an optimisation of the system with regards to the restrictive factor which is the irrigated land and as a risk management, two components that may be considered to evaluate the sustainability of these livestock farming systems and to propose development options.