Prevalence, Etiology, and Risk Factors of Mastitis in Dairy Cattle in Embu and Kajiado Counties, Kenya

Abstract

Bovine mastitis continues to be a leading cause of heavy economic losses in the dairy industry and a public health hazard globally. This cross-sectional study investigated the prevalence, etiologies of clinical and subclinical mastitis, and associated predisposing factors in Embu and Kajiado counties in Kenya. A semistructured questionnaire was administered to 154 smallholder dairy farmers to collect data on management practices, animal factors, and disease history. A total of 395 dairy cows were initially screened for subclinical mastitis using the California mastitis test (CMT), and milk samples were aseptically collected. Both CMT positive and CMT negative samples were analyzed using conventional bacteriological isolation and identification procedures. In the present study, the overall prevalence of mastitis based on CMT and clinical examination was 80% (316/395), out of which 6.8% (27/395) was clinical mastitis, while 73.1% (289/395) was subclinical mastitis. Based on culture, the overall prevalence of clinical and subclinical mastitis was 51.6% (815/1580), 74.4% (294/395), and 76.6% (118/154) at the quarter, cow, and farm level, respectively. From the 1574 milk samples analyzed by cultured, 1016 bacteria were yielded. The predominant bacteria were coagulase-negative Staphylococcus (CNS), 42.8% (435/1016), and in decreasing order, Streptococcus species, 22.2% (226/1016), Staphylococcus aureus, 15.7% (160/1016), and Pseudomonas aeruginosa, 5.1% (52/1016), and the least was Enterobacter species, 0.7% (7/1016), while 23.7% of the sample yielded no bacterial growth. Risk factor analysis revealed that milking mastitic cows last (p=0.002), using a clean udder drying towel for each cow (p=0.033) and previous history of mastitis (p=0.046) were significantly associated with presence of mastitis. The current study has shown a relatively high prevalence of subclinical mastitis with CNS as predominant bacteria. Therefore, control measures are urgently warranted. Management factors such as milking mastitic cows last, using a clean towel for udder drying for each cow, and culling mastitic cows should be considered and included in the Kenyan mastitis control programs.

Maintaining Optimal Mammary Gland Health and Prevention of Mastitis

“…The clinical manifestations of MG inflammation as well as its further course depend on the interplay between the innate resistance and adaptive immunity of the dairy cow and the type, concentration, and virulence of udder pathogens. If the MG has been infected with a large number of pathogens or more germs that are virulent and the host's defense systems have not been sufficient to control the infection, an clinical or chronic form of mastitis will develop ( 22 , 30 ).…”

Staphylococcus aureus and Dairy Udder

“…aureus, E. coli with Klebsiella. However, the maximum loss of production in multiparous is caused by Streptococcus spp., Staphylococcus aureus and others pathogens [46,47]. The loss of production is higher in multiparous cows than primiparous.…”

Identification and antimicrobial susceptibility of methicillin-resistant Staphylococcus aureus-associated subclinical mastitis isolated from dairy cows in Bogor, Indonesia

“…Globally, mastitis is an inflammation of the mammary gland, affecting dairy cows with high economic impact, including low milk production, increasing antibiotic residue contamination, and chronic infection, often leading to deaths [1,2]. It was reported that the prevalence of subclinical mastitis is higher than that of clinical mastitis [3]. Subclinical mastitis has a more common and serious impact on older lactating animals, contributing to most of the financial losses [2,4].…”

“…Subclinical mastitis has a more common and serious impact on older lactating animals, contributing to most of the financial losses [2,4]. The major risk factors for developing mastitis include herd size, bedding material, and milking of mastitic cows [1,3]. Meanwhile, the age and number of parity (number of pregnancies carried by a cow) were significantly associated with the occurrence of subclinical mastitis [5].…”

“…Staphylococcus spp. (coagulase-negative) are the predominant contagious pathogens causing mastitis [3,9]. At present, Staphylococcus aureus infection of the mammary gland remains a major problem in the dairy industry worldwide [10].…”