A cross-sectional stratified random sample survey of 1755 households in the Kenya highlands was conducted between
June 1996 and April 1998 to quantify cattle population dynamics in smallholder herds. The free-, semi-zero- and
zero-grazing systems practised represented increasing levels of intensification of the farms. Additional data were collected in
a follow-up survey of 50 households from the main survey sample. In the main survey there were 987 cattle-keeping
households, of which 44, 33 and 23% practised zero-, semi-zero- and free-grazing systems, respectively. Compared to
free-grazing, zero-grazing farms had a higher proportion of cows in the herd (0.62 vs. 0.51) but lower calving rates (0.52 vs.
0.69), higher losses of potential heifer replacements (0.47 vs. 0.38), fewer heifer replacements as a proportion of cows
disposed (0.46 vs. 1.11) and shorter productive life (3.8 vs. 4.8 years). Semi-zero-grazing farms had intermediate
performance. They and the zero-grazing farms were unable to maintain their herds without acquiring replacements
externally. Animal class mortality rates were high (7–19%) regardless of grazing system practised. Diseases accounted for
the largest proportion of animal exits: 85% of heifer-calves, 38% of heifers and 36% of cows. According to farmers’ ranking,
East Coast fever and Anaplasmosis diseases assumed less importance with a shift from free-grazing to zero-grazing system.
A household’s needs for cash was the second most frequent reason after disease for animal exits: 33% of heifers and 27% of
cows, indicating the importance of cattle as liquid capital assets. The results showed that many zero-grazed herds required
external sources of replacement animals to sustain their populations. Solutions to this constraint will include technical and
institutional innovations to serve small-scale farms that may result in greater complementarities between the small- and
large-scale production components of the dairy sub-sector