The overall prevalence of SM (at the cow and quarter level) was
high for both NRCS (80%) and RCS (70%) groups. This prevalence
agrees with the results of Mdegela et al. (2004) (62.4% and 82.4%),
Karimuribo et al. (2006) (75.9%), Kerro Dego and Tareke (2003)
(62.9%), and Kivaria et al. (2004) (90.3%) in crossbred or Holstein
cows in different regions of Africa. However, our results differ from
the low prevalence of SM reported by Almaw et al. (2008) (17% and
34%) and Getahun et al. (2008) (22.3%) on smallholder dairy farms
in Ethiopia. In our study, the overall prevalence of CM in NRCS cows
(5.8%) was higher than in RCS cows (1.3%). The prevalence of CM for
NRCS cows was higher than that reported by Almaw et al. (2008)
and Getahun et al. (2008) with 3.9% and 2.6%, respectively. The difference
in prevalence of SM and CM could be attributed to management
and/or environmental factors at the farm level. During the
present study, improper milking hygiene such as washing udders
Table 1
Distribution and grade of infection of sub-clinical mastitis (percentage), at the quarter level, in cows with and without residual calf suckling.
Treatment Lactation day
30 44 58 72 85 100 114 126
RCS NRCS RCS NRCS RCS NRCS RCS NRCS RCS NRCS RCS NRCS RCS NRCS RCS NRCS
Negative 11.0a 0b 62.5a 68.3a 8.3a 2.0a 70.8a 19.2b 84.6a 61.6b 88.6a 51.6b 72.9a 61.6a 77.2a 38.3b
Trace 69.4a 87.5a 28.5a 2.6b 83.3a 87.5a 18.7a 67.3b 5.7a 11.6a 9.0a 23.3a 12.5a 15.0a 13.6a 11.6a
+ 13.8a 5.0a 1.7a 3.3a 0a 4.1a 2.0a 1.9a 0a 6.6a 0a 8.3a 2.0a 5.0a 2.2a 5.0a
++ 5.5a 5.0a 3.5a 0a 4.1a 2.0a 2.0a 3.8a 1.9a 13.3b 0a 6.6a 6.2a 5.0a 2.2a 18.3b
+++ 0a 2.5a 3.5a 3.3a 4.1a 2.0a 6.25a 9.6a 7.6a 3.3a 2.2a 5.0a 4.1a 11.6a 4.5a 16.6b
RCS = residual calf suckling, NRCS = non-residual calf suckling.
Within each lactation day, different literal between columns indicate statistically significant differences P < 0.05.
Staphylococcus aureus
Coagulase-Negative Staphylococcus spp.
Pseudomonas aeruginosa
Enterobacter spp.
Klebsiella spp.