Prevalence of mastitis in smallholder dairy cattle in Pemba island, Tanzania

Abstract

A cross-sectional study was conducted from July to September 2010 to establish the prevalence of mastitis in smallholder dairy cattle in Pemba Island. The study also assessed factors contributing towards the increased occurrence of bovine mastitis in those dairy farms. Simple structured questionnaire survey, California Mastitis Test (CMT) and bacteriological culture were carried out to determine the magnitude and risk factors of clinical mastitis (CM) and subclical mastitis (SCM) on 93 dairy households randomly selected from four districts of Pemba. A total of 643 milk  samples from 163 lactating dairy cows were tested. The prevalence of clinical mastitis (CM) at farm level was 45.2% while at cow level was 31.3%.
The prevalence of subclinical mastitis as defined by CMT was 66.7% at farm level, 55.8% at cow level and 34.4% at quarter level. The prevalence of intramammary infection based on bacterial isolation was 68.4%, 56.86% and 35.7% at farm, cow and quarter level respectively. Herd size, number of lactating cows, age of the cow, lactation stage and amount of milk produced per cow per day and number of parity were the risk factors  identified to influence the prevalence of both clinical and subclinical  mastitis. Mastitis pathogens isolated from 429 milk samples submitted for bacteriological culture include Staphylococcus epidermidis (71.5%), Staphylococcus aureus (7.2%), Streptococcus spp. (1.3%), Klebsiella spp. (5.2%) and Escherichia coli (6.5%). The findings revealed that the  prevalence of both clinical and subclinical mastitis in smallholder dairy cattle in Pemba Island is high and appropriate control measures need to be devised.

Keywords: crossbred dairy cow, risk factors, smallholder dairy farmers, udder infection.