Subclinical mastitis: Prevalence and risk factors in dairy cows in East Java, Indonesia

BACKGROUND AND AIM: Subclinical mastitis (SCM) is a disease that frequently attacks lactating dairy cows and possibly decreases production, causing economic losses to farmers. This study aimed to define the prevalence of SCM and risk factor-associated related management practice by dairy farmers in East Java, Indonesia. MATERIALS AND METHODS: The milk sample per quarter of individual lactating Friesian–Holstein cows (592 samples) was collected from 148 cows from 62 selected farms in the region with high dairy cattle populations in Malang, Sidoarjo, Mojokerto, Probolinggo, Pasuruan, Lumajang, Jember, and Banyuwangi. SCM determination was performed using the California mastitis test. A survey including field observation and interviews with farmers was conducted to find out the management practices of the selected farms. The analysis of risk factors was conducted by multinomial regression using the IBM SPSS version 26.0 (IBM SPSS Statistics, Chicago, USA). RESULTS: In addition, 68.18% and 66.72% at the cow and quarter levels, respectively, of the lactating dairy cows examined had SCM. In multinomial regression, four variables were significantly given impact in association with the SCM prevalence in identifying related lactation stage (odds ratio [OR]: 1-2 months=5.67, 2-6 months=9.435), teat wiping after milking (OR=42.197), house cleanliness (OR: dirty=0.120, moderate=0.527), and location (regencies) of raising the cows (OR: Sidoarjo=0.076, Mojokerto=0.165, Jember=1.210, Probolinggo=3.449, Lumajang=1.638, Malang=1.210, and Pasuruan=0.681). CONCLUSION: The SCM prevalence in East Java is relatively high and a threat to the dairy industry’s performance. This study found a significant association with SCM that needs to be considered in the practice of management to prevent and control SCM. However, the finding also suggested that hygienic management practices performed by farmers need to be improved to reduce SCM incidents.