Prevalence of bovine tuberculosis and its effects on milk production in Red Chittagong cattle

Abstract

Bovine tuberculosis (bTB) is one of the most prevalent economically important zoonotic diseases and tuberculin test has been widely used to detect its prevalence worldwide. This study used a commercial immunochromatographic assay (ICGA) to detect the prevalence of bTB and to evaluate the differences in milk production between lactating cows with positive and negative results in Bangladesh. Thirty Red Chittagong (indigenous) cattle (RCC) were randomly selected from a herd of 87 RCC maintained at the Bangladesh Agricultural University Dairy Farm (BAUDF), Mymensingh during the period from March to July 2008, of which 30% cattle showed positive reaction to bTB. Of the 30 tested cattle, 35.29% (6/17) lactating cows, 20.0% (1/5) non-lactating pregnant cows, 33.33% (1/3) weaned calves and 20.0% (1/5) unweaned calves showed positive reaction to bTB. The detection of bTB in two calves and their respective mother cows indicates the possible transmission of TB organism through their colostrums / milk. Of the 17 lactating cows, 6 cows had positive and 11 had negative results to bTB. Cows with positive results produced less milk ( mean 1.29 litre / day / cow ) in comparison to cows with negative test ( mean 1.57 litre / day/ cow ) results which appeared as 17.83% reduction of milk production. Further study on the mastitis with or without bTB and its effect on milk production require data of more herds for conclusion of these results. Key words: Red Chittagong cattle, bovine tuberculosis, immunochromatographic assay, milk production doi: 10.3329/bjvm.v6i2.2332 Bangl. J. Vet. Med. (2008). 6 (2): 175-178