Cross-Sectional Study on Prevalence, Risk Factors and Major Bacterial Causes of Bovine Mastitis in and Around Wolaita Soddo, Southern Ethiopia

Abstract

A cross-sectional study was conducted from November 2014 to March 2015 on lactating dairy cows to determine the overall prevalence of bovine mastitis, assess concomitant risk factors and isolate the major bacterial agents involved in causing mastitis in and around Wolaita Soddo. A total of 320 lactating cows were examined for mastitis using clinical examination and California mastitis test (CMT). Bacteriological methods were also done to isolate the causative bacteria. An overall 26.25% prevalence of mastitis was recorded in the area of which 12/84 (3.75%) were clinical and 72/84 (22.50%) subclinical cases. About 125 bacterial isolates belong to 5 species were identified from mastitic milk samples. The isolates based on their relative frequency of occurrence were Staphylococcus aureus (39.85%), Coagulase Negative Staphylococcus (CNS) (20.30%), Streptococcus dysgalactiae (13.53%), Streptococcus agalactiae (12.03%), Escherichia coli (8.27%). In this study risk factors like parity, lactation stage, and body condition were shown association with mastitis. Animals with many parity Odds Ratio (OR: 3.55, 95% CI: 1.64 – 7.67, P value: 0.001), moderate (OR: 1.49, 95% CI: 0.76 – 2.91, P: 0.242) were at higher risk than animals with few parity. Animals with early lactation (OR: 3.93, 95% CI: 2.02 -7.66, P: 0.001), mid lactation (OR: 1.63, 95% CI: 0.75 – 0.54, P: 0.214) were at higher risk than animals with late lactation. Animals with poor body condition (OR: 3.53, 95% CI: 1.58 – 7.85, P: 0.002), medium body condition (OR: 1.51, 95% CI: 0.68 – 3.35, P: 0.308) were at risk than animals with good body condition. Generally, the study showed that mastitis was a serious problem for dairy production in the study area. Therefore, appropriate control measures targeting the specific causative agents should be in place to reduce the impact of the disease. The farmers should also be aware of the impact of the disease and practice hygienic milking, culling of chronic mastitis carriers and treating of clinically infected cows.

Keywords: Dairy cattle, Mastitis, Milk, Risk factor, Wolaita Soddo