Prevalence of subclinical mastitis and associated risk factors in dairy farms in urban and peri-urban areas of Thika Sub County, Kenya

Abstract

Abstract A cross sectional study was carried out to investigate the prevalence of subclinical mastitis in dairy cattle, determine the most frequent of intramammary infections and evaluate associated risk factors affecting subclinical mastitis in the urban and peri urban areas of the Thika Sub county. 172 lactating cows of different ages, parities and lactation stages on 13 smallholder farms were sampled. Milk samples from 172 animals and 688 udder quarters were tested for subclinical mastitis using a California mastitis test. Milk samples from California mastitis test (CMT) positive cows and quarters were collected for further bacteriological analysis. Risk factors were also recorded during sampling.

The results showed that 110 cows out of 172 representing 64 % were CMT positive for subclinical mastitis in the study area. At the quarter level of 688 active quarters tested for subclinical mastitis, 384 (55.8%) were positive to CMT test. Breed, udder hygiene, stage of lactation, parity and floor type had a significant influence on the prevalence of subclinical mastitis. Among the breed, Ayrshire had a high prevalence 80.6%. Mid stage of lactation and multiparous animals had the highest prevalence of 77.8% and 70.1% respectively. Dirty udder and animals housed in muddy soil floor type had a significantly higher prevalence of subclinical mastitis. The study concludes that there is a high prevalence of subclinical mastitis in smallholder dairy farms in urban and peri-urban regions of the Thika sub - county. The study recommends that in order to reduce high prevalence of subclinical mastitis, smallholder farmers require to keep the udder clean, mostly in the wet season, improve floor conditions through regular cleaning of the floor or upgrade to the concrete floor.

Key words: California mastitis test, floor type, lactating dairy cows, Staphylococcus aureus