Table 1 Model components and assumptions

Household characteristics and food needs

• The model used a household of six people, comprising two adults and four children (UBOS 2018).

• Food energy needs per person were assumed to be 2100 kcal/day.

Livestock herd and production

• Milk in agro-pastoralist households in Karamoja is derived mainly from cows and goats.

• Milk production and offtake depend on the number of cows and does of breeding age, reproductive performance, production, and herd management.

• Production losses include losses due to disease and drought.

• Information on livestock herd production in Karamoja is limited, but relevant information is available from comparable pastoralist systems in East Africa.

• The food energy value of cow and goat milk is known.

Land and crop production

• The area of land available from cropping is limited by the use of hand tools and manual labour; the model used a land area of 0.4 ha cultivated.

• For the sake of simplicity, the model used sorghum as the single crop produced by the household.

• Limited information is available on sorghum yields in Karamoja, or losses due to pests, rainfall variability, and other causes; information on post-harvest losses is also limited. Sorghum yields were averaged from estimates provided by the Nabuin Zonal Agricultural and Research Development Institute.

• The food energy value of sorghum is known.

Market behaviour and price data

• Good information is available on the prices of livestock and cereals in Karamoja; the model used average prices for 2017.

• The model assumed that the household sold young male goats and bulls and retained breeding females; this approach is consistent with maximizing herd growth while also selling animals to meet domestic needs.