Prevalence and Etiology of Subclinical Mastitis in Small Ruminants of Tigray Regional State, North Ethiopia

Abstract

A study was conducted at Kafta Humera and Tanqua Abergelle Districts from April to June, 2011 to assess the prevalence of subclinical mastitis in lactating small ruminants and identify bacterial causative agents. A total of 390 lactating animals comprising 255 goats and 135 sheep were randomly selected from population and screened for evidence of subclinical mastitis. The overall prevalence of subclinical mastitis was found to be 18.03% (46/255) and 28.14% (38/135) in goats and sheep, respectively. California mastitis test (CMT) positive milk samples were subjected to bacteriological examination and the following bacteria were isolated; coagulase negative Staphylococcus (44.7%), Staphylococcus aureus (27.7%), Escherchia coli (17.0%) and streptococci (10.63%). Risk factors; species (p = 0.021), study site (p < 0.001), sheep breed (p = 0.018) and goat breed (p = 0.009) showed statistically significant association with the occurrence of subclinical mastitis in small dairy ruminants. However, there was no statistically significant association between risk factors such as Age (p = 0.779), parity (p = 0.201) and stage of lactation (p = 0.952). Therefore, it can be concluded that mastitis is a significant disease in small ruminants that affects their productivity and measures need to be taken to control the disease.