Isolation and Identification of Streptococcus Uberis in Lactating Cows of Haramaya University Dairy Farm

Abstract

A cross-sectional study was carried out in 40 lactating dairy cows of Haramaya University dairy farm from November 2014 to April 2015 to isolate Streptococcus uberis and assess risk factors. A checklist, farm inspection, and clinical examination of cattle were employed to collect data before laboratory examination of milk samples. Lactating animals were examined for the presence of clinical signs of mastitis. Physical examination of milk samples and California Mastitis Test (CMT) were conducted. Milk samples collected from clinically mastitic cows and CMT positive samples were subjected to microbiological examinations. Isolation and identification of Streptococcus uberis were carried out according to standard microbiological procedure. From 40 cows udders examined, 17 (42.5%) and 3 (7.5%) were sub-clinically and clinically affected, respectively. Streptococcus uberis was isolated from 2 (5%) of these cows. Out of 160 quarters examined, 11 (6.88%), 20 (12.5%) and 50 (31.25%) of the quarters were blind, clinically mastitic and sub-clinically mastitic, respectively.
Streptococcus uberis was isolated from hind quarters of two sub-clinically mastitic dairy cattle. In conclusion, the present study revealed low isolation rate, however, it’s potential to spread and negative impact on quality milk production should not be neglected. Therefore, emphasis should be given to the control of mastitis due to this pathogen by improving hygienic and sanitation management measures.