Comparison of Two Regimens of Nigella sativa Extract for Treatment of Subclinical Mastitis Caused by Staphylococcus aureus

Problem statement: Little research has focused on treatment of cows with subclinical mastitis during lactation. The seed of Nigella sativa Linn. (Ranunculaceae), commonly known as black seed or black cumin, is used in folk (herbal) medicine. Approach: Objectives of this study were to evaluate the effect of Nigella sativa Extract (NSE) with two regimens for treatment of subclinical mastitis in lactating dairy cows and to determine which regimen enhanced efficacy of it. Results: From one hundred Holstein dairy research herd in Mashhad-Iran, 83 cows with a total of 157 subclinically Staphylococcus aureus infected quarters were included. Cows were enrolled in the study based on milk somatic cell counts >200,000 mL^-1 and isolation of Staphylococcus aureus in 3 samples obtained 1 week apart. About 10 cc of NSE (in paraffin: 200 mg cc^-1) was administered via intramammary infusion. First, Cows were divided into three treatment groups. Group 1 (37 cows) received intramammary infusion at each milking (3 times daily) for 3 days with 10 cc NSE. Group 2 (24 cows) received the same intramammary infusion but only once daily for 3 days. The third, 22 cows were included as an untreated negative control group. Results in bacteriologic cure of 69.4% of quarters and 59.5% of cows (Group 1) compared to 60% of quarters and 45.8% of cows (Group 2). Test for mastitis diagnosis Somatic cell counts of milk from quarters that were not cured were higher prior to initiation of treatment than those cured. A bacteriological cure was defined as a treated infected mammary quarter that was bacteriologically negative for the presence of S. aureus at 3-7 day after the last treatment. Conclusion: All two Nigella sativa treatment regimens were significantly better than the negative control and the nine dose Nigella sativa treatment regimen treatment group was not significantly better than the three dose treatment group (p = 0.332).