Kassaye Aragaw

Major causes of mastitis and associated risk factors in smallholder dairy farms in and around Hawassa, Southern Ethiopia

A cross-sectional study was carried out from October 2008 to May 2009 in smallholder dairy farms in and around Hawassa to estimate the prevalence of mastitis, to isolate and characterize major bacterial pathogens, and to identify possible associated factors. The study involved a total of 201 milking cows randomly drawn from smallholder farms. The prevalence of clinical and subclinical mastitis was determined through clinical examination of the udder and using mastitis indicator paper (Bovivet® indicator paper, Kruuse, Denmark). The prevalence of mastitis at cow and quarter level was 30.3 (61/201) and 10.3 (79/766), respectively. Subclinical mastitis was 25.4% and 5.0% was clinical. Stage of lactation significantly affected (P < 0.05) the prevalence of mastitis, with the highest prevalence observed in the late stage of lactation (41.3%) as compared to early (25.0%) and mid (22.1%) stages of lactation. Floor type and bedding had association (P < 0.05) with mastitis prevalence. Cows housed in concrete-floored houses had lower prevalence (19.0%) of mastitis compared to cows kept in soil-floored houses (47.6%). Mastitis prevalence was low in farms which do not use bedding (23.5%) as compared to farms using hay/straw bedding (37.4%). However, age, parity, and history of mastitis had no association (P > 0.05) on the prevalence of mastitis. The pathogens isolated from mastitic cows were Staphylococcus aureus (48.6%), other staphylococci species (15.7%), Streptococcus agalactiae (11.4%), other streptococci (17.1%), Bacillus species (2.9%), and coliforms (Escherichia coli and Klebsiella species) (4.3%). Strict hygienic measure of housing and bedding should be considered, in reducing the prevalence of mastitis.

Survey of ixodid ticks in domestic ruminants in Bedelle district, Southwestern Ethiopia

A survey aimed at determining the status of ticks in cattle, sheep and goats in Bedelle district (Southwestern Ethiopia) was carried out from November 2007 to April 2008. Out of the total 330 animals examined, 314 (95.2%) were found to be infested (harbouring of at least a single tick). High rates of infestations were recorded across all three host species. Factors like month of collection, age and sex of host species did not show significant association with infestation rates. A total of 5,507 ticks belonging to three genera (i.e. Amblyomma, Boophilus and Rhipicephalus) were collected during the study period of which six species were identified. The species of ticks encountered comprise of Amblyomma cohaerens (44.1%), Amblyomma variegatum (13.8%), Amblyomma lepidum (1.2%), Boophilus decoloratus (24.9%), Rhipicephalus evertsi evertsi (14.3%) and Rhipicephalus lunulatus (1.7%). As about 86.7% (4,772) of the ticks were collected from cattle, it was recognised that this could be an evidence of host preference where cattle are serving as principal host while sheep and goats serve as alternative hosts. The role of ecological factors and little attention paid by livestock owners for treatment of animals against ticks are suggested to result in the abundance of ticks. Acaricide spraying should be strategically applied to control ticks. Better result could be achieved if an emphasis is being put on spraying cattle. Studies on tick-borne diseases, involvement of wildlife species as well as related factors are recommended as they may provide a valuable basis for designing and launching an all-round control programme in the country.

Major causes of mastitis and associated risk factors in smallholder dairy cows in Shashemene, southern Ethiopia

A cross-sectional study was conducted from October 2010 to May 2011 to estimate the prevalence of mastitis, isolate and characterize major bacterial pathogens and to assess the association of some putative risk factors with occurrence of mastitis in cows in smallholder dairy farms in Shashemene, southern Ethiopia. A total of 245 lactating cows (111 Holstein, 98 Holstein-local Zebu crosses and 36 indigenous Zebus) were examined clinically and California Mastitis Test (CMT) was used to detect clinical and subclinical mastitis. The overall prevalence of mastitis at cow and quarter level was 37.1% (91/245) and 30.0% (288/960), respectively. Seventy (28.6%) cows were with subclinical mastitis while only 20 (8.6%) had clinical mastitis. The prevalence of mastitis significantly (P<0.05) differed with breed, parity, stage of lactation and previous record of mastitis. A total of 217 bacterial isolates were recovered from 288 mastitic milk samples and Gram-positive cocci were the most common pathogens. The pathogens isolated were Staphylococcus aureus (28.1%), other Staphylococcus species (22.1%), Streptococcus agalactiae (10.1%) other Streptococcus species (14.3%), coliforms (22.1% that is Escherichia coli, 10.6%; Klebsiella species 7.8% and Enterobacter species 3.7%), Micrococcus species (1.4%), Pseudomonas species (1.4%) and Bacillus species (0.5%). Therefore, culling of older cows with repeated mastitis records and dry cow therapy will be practiced to reduce the risk of mastitis. Culling of old and chronically affected cows, screening for mastitis, awareness creation among smallholder farmers about the importance of sub-clinical mastitis and milking and barn hygiene should be considered in reducing the effect of mastitis.

A field trial of production and financial consequences of helminthosis control in sheep production in Ethiopia

We used a partial-budget analysis to evaluate profitability of different management strategies of three genotypes of sheep in a 2 x 2 x 3 factorial experiment conducted at Debre Berhan research station in the central highlands of Ethiopia. This involved two anthelmintic-treatment levels (treated vs. non-treated), two supplementary nutrition levels (protein-energy supplementation yes/no) and three genotypes: indigenous Menz (n=40), 50% Awassi x 50% Menz crosses (n=38) and 75% Awassi x 25% Menz crosses (n=31). All sheep were exposed to natural sub-clinical helminthosis challenge. Supplemented sheep were offered a concentrate mix daily on an individual basis. Anthelmintic-treated sheep were drenched with fenbendazole against nematodes and with triclabendazole against trematodes. Data were collected during the experimental period (for 10 months from approximately 1 year of age) on feed intake, live weight, eggs per gram (EPG) of faeces, packed-cell volume (PCV), wool weight, and adult-worm burden. Actual market input and output prices were recorded. Supplemented sheep had significantly higher marginal profit (MP) per sheep than non-supplemented sheep (ETB 33 vs. 4). Likewise, anthelmintic treated sheep performed significantly better than their non-treated contemporaries (MP=ETB 28 vs. 8). The 75% Awassi crosses were least profitable.

Characterization of Salmonella isolated from apparently healthy slaughtered cattle and retail beef in Hawassa, southern Ethiopia

The present study was conducted to determine the occurrence, serotype distribution and antimicrobial resistance of Salmonella serotypes in slaughtered cattle, slaughterhouse environment and retail beef. Cecal content (CC), mesenteric lymph nodes (MLN), spleen and carcass swab (CS) samples (each, n=150) were collected from 150 cattle slaughtered at Hawassa municipality slaughterhouse. Floor swab specimens (SHFS) were collected on 11 occasions from the slaughterhouse, and 100 beef samples were collected from 100 butcher shops. The samples were cultured for Salmonella, following standard procedures. A total of 14 Salmonella isolates belonging to 3 serotypes namely Salmonella enterica serotype Muenchen (4 isolates), S. enterica serotype 1,4,5,12:i:- (5) and S. enterica serotype Korovi (5) were recovered. All of the 5 S. enterica serotype 1,4,5,12:i:- isolates belonged to phage type 120. Four (2.7%) of the slaughtered cattle carried Salmonella in their CC and/or MLN, while none of the spleen samples were positive for Salmonella. Salmonella was isolated from four (2.7%) CC and two (1.3%) MLN samples. Out of the total of 150 CS samples, two (1.3%) were found contaminated with Salmonella, while 4 (4%) of the 100 beef samples obtained from butcher shops yielded Salmonella. Two of the 11 (18%) SHFS were positive for Salmonella. All the four isolates from beef were S. enterica serotype Muenchen, while both of the isolates from MLN were S. enterica serotype1,4,5,12:i:-. Both S. enterica serotype1,4,5,12:i:- and S. enterica serotype Korovi were isolated from CC, CS and slaughterhouse environment. All the 14 isolates recovered during the study were tested and found pan-susceptible to a panel of 14 antimicrobials. The present study helped to update the information on the occurrence, serotype distribution and antibiogram of Salmonella in slaughter cattle and beef in Ethiopia.

Asymptomatic Bacteriuria in Relation to Diabetic Women Attending Hawassa University Referral Hospital, Southern Ethiopia

The aim of the current study was to investigate the association between diabetes and ASB in women, identify the bacteria involved and determine their antimicrobial resistance. Diabetic (n=100) and non-diabetic (n=100) nonpregnant women, with no abnormalities of the urinary tract were involved in the study. Clean-catch midstream urine samples were collected for bacterial isolation and identification. Questionnaire was used to collect demographic and clinical information of the patient. ASB was diagnosed in 22(22%) diabetic and 15(15%) nondiabetic women. Escherichia coli, Staphylococcus aureus, coagulase negative staphylococci, Klebsiella pneumoniae and Proteus species were isolated from both groups of study subjects. There was no statistically significant difference in the relative frequency of isolated bacteria species among the two groups of patients (P>0.05). Most of the isolated bacteria were resistant to amoxicillin (96%), penicillin (92%) and vancomycin (70%), but susceptible to ceftriaxone (60%), norfloxacin (62%) and gentamicin (62%). Occurrence of ASB was not associated with diabetic status in women attending Hawassa University Referral Teaching Hospital.