Epidemiological and Bacteriological Study on Caprine Subclinical Mastitis in Khartoum State, Sudan

Abstract

The prevalence of caprine subclinical mastitis in Khartoum State was assessed by California Mastitis Test. Milk samples were also analyzed for the isolation and identification of bacterial agents that might be associated with caprine subclinical mastitis including their antibiotic sensitivity test against commonly used antibiotics. In addition, the influence of certain risk factors on the prevalence of caprine subclinical mastitis was also evaluated. Milk samples were collected from 246 goats (475 udder halves). The overall prevalence of caprine subclinical mastitis as determined by California mastitis test was 13.8%. On an udder half basis the prevalence was 10.1%. Certain risk factors associated with caprine subclinical mastitis, were identified. The prevalence was higher in ≥5 years old animals (p-value = 0.000; Exp (B) = 5.559; 95.0% CI: 2.149 to 14.376), ≥4 parity (p-value = 0.022; Exp (B) = 3.660; 95.0% CI: 1.206 to 11.103), poor body condition (p-value = 0.009; Exp (B) = 6.130; 95.0% CI: 1.655 to 23.987), and in goats with udder lesions (p-value = 0.013; Exp (B) = 10.532; 95.0% CI: 1.653 to 67.093). The prevalence was also higher in farms where mastitic goats were kept together with healthy ones in the same house (p-value = 0.028; Exp (B) = 6.343; 95.0% CI: 1.215 to 33.100). The predominant bacterial species isolated from milk that were collected from the subclinical mastitis positive cases were Coagulase-negative staphylococcus 34.2%, Staphylococcus aureus 23.7%, Micrococcus spp. 15.8%, Bacillus spp. 18.4%, Streptococcus spp. 2.6%, and mixed bacteria 5.3%. These isolates of bacteria showed various degrees of sensitivity to the antibiotics used in the study. It is suggested that because of the prevalence of subclinical mastitis in this species of animal, farmers should be aware of the problem so as to institute preventive and control measures to reduce losses due to this disease in dairy goats.