Across sectional study of epidemiological risk factors and associated bacterial pathogens was conducted on 216 lactating dairy cows in jimma town from Oct. 2016 to April 2017 to determine the overall prevalence rate, associated bacterial pathogens and to assess effect of risk factors on prevalence of mastitis. Upon physical examination of udder and teats the prevalence of clinical mastitis was 2.3% at cow level and 0.96% at quarter level. Using the California mastitis test (CMT) for detection of sub clinical mastitis, the prevalence of sub clinical mastitis at cow level and quarter level was 60.65 and 38.4% respectively. The overall prevalence of mastitis was 62.96. Out of 323 (38.4%) CMT positive quarters with evidence of sub clinical mastitis, the quarter infection rate for the right rare quarter was highest (41.3%) followed by left rear (38.8%), right and left front (each 36.7%). Up on microbiological examination of milk samples for both clinical and subclinical quarters, out of a total of 331 cultured, 271(81.9%) yielded bacteria whereas 60(18.1%) yielded no bacteria. A total of 263 bacterial pathogens were isolated whereas 8 were mixed infections with more than two different colonies. The main bacterial pathogens isolated were coagulase negative staphylococci (CNS) (26.6 %), Staphylococcus aureus (24.7%), Escherichia coli (13.31%), Streptococcus species (9.13%), and Pseudomonas aeruginosa (8.8%). Other bacteria isolated with low isolation rate were micrococcus species (3.04%), Corynebacterium species (3.4%), Actinomyces pyogenes (3.8%), Bacillus species (3.42%) and other gram negative rods (3.8%). Host factors such as breed, age parity and lactation stage had significant effect on the prevalence of mastitis (p‹0.05). Managemental and environmental factors such as bedding, ventilation, frequency of barn cleaning, udder washing and use of communal towel had significant effect on the occurrence of mastitis (p‹0.05). Whereas milking practice, drainage had insignificant effect on the prevalence of mastitis (p›0.05).

Bovine brucellosis is an infectious zoonotic disease causing significant economical loses in dairy industry. A cross-sectional study was carried out between October 2017 and July 2018 to estimate the seroprevalence and its associated risk factors in smallholder dairy farms in Hawassa town, Southern Ethiopia. A total of 370 blood samples were collected from cross-bred and local indigenous dairy cattle of above six months of age. One stage cluster sampling technique was used to get the sample of interest. Rose Bengal Plate Test (RBPT) was used as a screening, while serum samples testing positive to RBPT were subjected for complement fixation test (CFT) to confirm. Consequently, RBPT detected 18 of the 370 samples positive for brucellosis exposure. The positive sera when further retested using CFT, 10 out of the 18 RBPT positive sera were confirmed to be positive. The individual animal level prevalence of bovine brucellosis in the study area was 2.7% and the herd-level prevalence was 25.8%. Higher prevalence was observed in larger herd sizes than the small and medium herds (p<0.05). Likewise, parity number greater than six had more positive animals (p<0.05) than the corresponding group with lower parity number. Multivariable logistic regression anlysis revealed that herd sizes (

Five tropically adapted buck breeds extensively managed in Ethiopia were studied to determine possible effects of breed and age on body size and testicular traits. In all, 177 bucks were selected following stratified random sampling, and evaluated in three age groups: <14 months (young), 14-19.5 months (intermediate) and 19.6-24 months (old). The breeds studied were Arsi-Bale (AB; N = 35), Central Highlands (CH; N = 33), Afar (N = 35), Boran (N = 36) and Woito-Guji (WG; N = 38). In all the three age groups, Boran and CH bucks were the heaviest (p < 0.05), Afar were the lightest, and AB and WG were in between. The highest body weight (BW) was achieved in the intermediate age group for Afar, but in the oldest age group for the other breeds. In the youngest age group, scrotal circumference (SC) was the widest (p < 0.05) for Boran and CH and the narrowest for Afar, AB and WG, while in the intermediate and the oldest age groups, Boran showed the widest SC. Boran, WG and CH had higher (p < 0.05) testicular weight (TW) than Afar and AB in the youngest age group. Boran retained the highest (p < 0.05) TW in the intermediate and the oldest age groups, while in the oldest age group WG and AB medium TW and Afar had the lowest TW. However, Afar had the highest TW expressed as percentage of BW. SC was well correlated with TW (p < 0.001; r = 0.74) and BW (p < 0.001; r = 0.61), indicating a linear, positive association between BW and TW (p < 0.001; r = 0.51). In conclusion, body size and testicular traits of Ethiopian bucks under an extensive management system are influenced differently by breed and age group.