Impact of mastitis control measures on milk production and mastitis indicators in smallholder dairy farms in Kiambu District, Kenya

Bovine mastitis and mastitis control were investigated on smallholder farms in central Kenya. After an initial observational study, a clinical trial t o assess the impact of three different mastitis control strategies - (1) im proved udder hygiene, (2) treatment of subclinical cases, and (3) a combina tion of these - was conducted on 100 randomly selected farms with 332 lacta ting cows. Before the implementation of control measures, the milk yield wa s low (mean 6.5 kg/day; median 6 kg/day) and somatic cell counts (SCC) were high, with 80% and 43% of cows having milk with SCC greater than 250 x 10( 3) cells/ml and 600 x 10(3) cells/ml, respectively. Infectious pathogens we re also commonly isolated, with 63% of cows being positive for pathogenic b acteria. Neither intervention strategy alone had any effect on mastitis ind icators or milk yield. In combination, the measures had some impact, loweri ng the prevalence of contagious pathogens by 18%, but this was not reflecte d in a significantly increased milk yield, lowered SCC or reduced incidence of clinical mastitis.