Somatic cell counts and bacteria in milk from two nomadic herds in Abeokuta, Nigeria

Abstract

Mastitis, the inflammation of the mammary gland, is a major endemic disease affecting dairy production worldwide. Costs of treatment and control of mastitis contributes to major losses to the dairy industry especially if the condition is not promptly and accurately diagnosed, thus necessitating the engagement of regular and reliable means of recognising intra-mammary infections. Somatic cell counting, which has been recognized as a major standard for mastitis diagnosis in milk, was utilized in this study as a direct measure of intramammary inflammation (IMI), along with bacterial culture and isolation to establish the presence of mammary infections in cows from two nomadic herds. Milk from all four quarters (composite samples) of each of 100 cows at various stages of lactation, were obtained and subjected to Levowitz-Weber staining of duplicate smears and direct microscopic counting of somatic cells. Culture and isolation of sterile milk swabs and subsequent identification by morphology, gram staining and biochemical tests were employed to assess the presence of mastitis-causing pathogens in the samples. Using ≤100,000 cells/ml as cut off for non-mastitic milk, sub-clinical mastitis (SM), was determined in 70 (70%) of the examined samples. Contagious pathogens, namely; Staphylococcus aureus, Staphylococcus species and others as well as environmental bacteria, E. coli and Enterococcus species amongst others, were isolated from the samples. This result circuitously indicates the level of losses to dairy production through poor milk quality and yield, costs of treatment and culling obtainable in the nomadic dairying venture. The need for routine evaluation of raw milk and other dairy products emanating from the itinerant pastoralists, using sensitive and reliable parameters to facilitate prompt diagnosis, targeted treatment and rapid control of cow to cow or herd to herd spread of IMI is highlighted in this study.