Abstract:
A cross sectional study was conducted from October 2016 to February 2017 on
smallholder dairy farms to determine the prevalence of bovine mastitis, associated risk
factors and its effect on milk microbial quality under different production systems of
Borena District, South Wollo Zone, Amhara Region, Ethiopia. A total of 180 households
were interviewed using semi structured questionnaire concerning the different potential
risk factors for mastitis prevalence and 229 lactating cows were used for clinical
examination and California Mastitis test (CMT) screening and monitoring of 30
clinically affected cows were performed for three month after treatment with intra
mammary fusion (amoxicillin) for three days. In addition to this effect of mastitis on milk
microbial quality were examined by taking a total of 30 mastitis positive milk samples
were collected from mixed farming and peri urban smallholder farmers. The result of this
study indicated that higher prevalence of mastitis in peri urban production system
(87.0%) than mixed farming system (68.6%); subclinical mastitis was more prevalent
(55.5 %.) than clinical mastitis (17.5%). Out of 916 examined quarters, 5.4% of them
were clinically affected, 1.5% quarters were blind and 46.7% were positive to CMT test.
Besides, host and environmental risk factors had significant effect on mastitis prevalence.
Moreover the mean total bacterial count (TBC) was significantly different (P < 0.05) in
which average TBC from two production systems were 6.85± 0.14 and 7.00± 0.11 for
mixed farming and peri urban, respectively, The average TBC (6.93±0.13) found in milk
samples collected in this study failed to comply the standard set for raw milk intended for
direct human consumption (4.6 log cfu/mL). However the mean coliform count (CC) was
not significantly different (P < 0.05) among the two production systems. The mean value
of CC from current study milk samples collected from mixed farming and peri urban milk
producer households were 4.99± 0.11 and 5.05± 0.09, respectively. The overall mean CC
(5.02±0.10) observed in the current study did not meet the standard quality milk for
human consumption. Out of 30 CM positive monitored cows only 43.3 % of them were
recovered. In general mastitis prevalence was higher and the microbial quality of milk
was poor due to udder infection. To overcome this problem awareness creation among
dairy cow owners on how to keep the udder clean, to improve floor conditions through
regular cleaning of the floor and medical intervention is needed to improve mastitis
prevention and control programs in the study area
