Prevalence and determinants of Mastitis and Milk-borne Zoonoses in smallholder dairy farming sector in Kibaha and Morogoro districts in eastern Tanzania
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Date
2004-11-22
Journal Title
Journal ISSN
Volume Title
Publisher
Journal of Veterinary Medicine
Abstract
A study was carried out to establish the prevalence and determinants
of mastitis and milk-borne zoonoses in smallholder
dairy farms in Kibaha and Morogoro districts (Tanzania). A
total of 57 herds comprising 114 milking cows in Kibaha and 48
herds consisting of 96 milking animals in Morogoro were
included in the study. A questionnaire survey was used to assess
the socio-economic determinants of mastitis, whereas California
mastitis test (CMT) and microbiological assessment of milk
was carried out to establish the status of mastitis and responsible
aetiological agents. Seroconversion for brucellosis was
evaluated using enzyme-linked immunosorbent assay (ELISA).
Animals were also tuberculin-tested using a single comparative
intradermal method and milk samples were cultured for isolation
of Mycobacterium species. Based on CMT, the cow-based
prevalence of subclinical mastitis was 82.4% in Kibaha and
62.4% in Morogoro. Of the 919-quarter milk samples cultured,
8.2% were positive for aerobic bacteria with predominant
isolates being Staphylococcus epidermidis (2.8%), Staph. aureus
(1.7%), Streptococcus agalactiae (1.2%) and Staph. intermedius
(1.1%). There was a strong association between CMT positivity
and bacteriological isolation [relative risk (RR) ¼ 2.60;
P ¼ 0.02]. Fungal growth was observed in 21.8% (n ¼ 881) of
the samples and the isolates were yeast (19.2%), Mucor (2.5%)
and Aspergillus (0.1%). Bucket feeding of calves was associated
with increased risk of a quarter being CMT positive
(RR ¼ 1.24; P ¼ 0.000), while residual calf suckling was
associated with decreased risk of positivity (RR ¼ 0.86;
P ¼ 0.015). Earth floor was associated with increased risk of
CMT positivity at quarter level (RR ¼ 1.13; P ¼ 0.041) and
Jersey breed was identified as a risk factor to mastitis. The
prevalence of bovine tuberculosis was 0.4% (n ¼ 259) and
1.7% (n ¼ 181) in Kibaha and Morogoro, respectively. Similarly,
the prevalence of brucellosis was 1% (n ¼ 208) in Kibaha
and 1.9% (n ¼ 104) in Morogoro. Findings from this study
have demonstrated a high prevalence of subclinical mastitis and
existence of health risks to milk consumers despite the low
prevalence of tuberculosis and brucellosis in the study herds.
Description
Journal of Veterinary Medicine B 2004, Vol 51: 123–128
Keywords
Dairy Farming Sector, Milk-borne Zoonoses, Tuberculin-tested, Smallholder dairy farms, Mastitis