Bovine Mastitis in Zebu and Crossbred Cattle under the Extensive Management System in Tanzania

M N Shem,D Kambarage,F A Mosha,R Machangu,T Fujihara

doi:10.5713/ajas.2002.751

Abstract

A study was carried out to evaluate the incidences and causes of bovine mastitis in Tanzanian shorthorn zebu (Bos indicus) in the traditional sector and crossbred cows (Bos taurus×Bos indicus) in the dairy ranching sector, both found under the extensive range management system. Management practices were evaluated through a survey study using structured questionnaires. A total of 120 lactating cows (60 cows from each sector) were screened for the disease using the California Mastitis Test (CMT). Confirmatory tests used for infected cows included; the Direct Microscopic Somatic Cell Count (DMSCC), culture, bacteriological and biochemical laboratory assays. Survey results showed that management practices were generally very poor in both sectors with 84% of the surveyed herds being kept and milked under very unhygienic environmental conditions. The level of infection was higher in the crossbred cows (5% clinical and 38.3% sub-clinical mastitis) and lower in the zebu cows with only sub-clinical mastitis (23.3%). Crossbred cows had (p<0.05) higher somatic cell counts than zebu cows. The four highest-ranking bacterial isolates in order of importance were Staphylococcus aureus, Escherichia coli, Streptococcus agalactiae and Bacillus spp. It was concluded that bovine mastitis under the extensive management system in Tanzania was a result of poor management practices and that zebu cows were more resistant to the diseases than crossbred cows. (Asian-Aust. J. Anim. Sci. 2002. Vol 15, No. 5 : 751-756)

Highlights

IntroductionEurope and elsewhere in efforts to improve the genetic potential for milk yield by local zebu cattle through crossbreeding
Modernization of the dairy industry in Tanzania has involved the introduction of exotic breeds of cattle fromEurope and elsewhere in efforts to improve the genetic potential for milk yield by local zebu cattle through crossbreeding
Survey results showed that management practices were generally very poor in both sectors with 84% of the surveyed herds being kept and milked under very unhygienic environmental conditions

Summary

Introduction

Europe and elsewhere in efforts to improve the genetic potential for milk yield by local zebu cattle through crossbreeding. Accompanying this has been mastitis, a disease of the udder, which has become widespread in the country (Msanga et al, 1989; Shekimweri et al, 1998; Shem et al, 2001). The disease is of economic importance as it can cause serious economic losses; thorough reduced productivity by cows (Blood and Radosttis, 1985) and high veterinary costs (Shekimweri et al, 1998). Hand milking is the most common method used to milk cows both in the modern dairy and in the traditional sectors in Tanzania.

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