[The effect of teat dipping with jodophores on udder health and the iodine content of the milk (author's transl)].

The effect of teat-dipping with iodophore preparations on the incidence of mastitis was investigated for a period of 13 months in (i) 7 herds averaging 52 cows with an iodophore solution (JO-BAC¿ Superdip, 0.5 % active iodine) and in (ii) 9 herds averaging 47 cows with an iodophore solution (F 1042, 0.33 % active iodine). Teat-dipping was performed after each milking. The udder health of 8 herds averaging 28 cows was followed as a control (iii). Udder health was studied by CMT and bacterial examination of udder quarter samples every 10th week and by electronic cell counts of bulk milk every month. The mean incidence of infection at the beginning and end of the trial, the incidence of newly infected cows and quarters during the trial for each group was (i) 13.0 leads to 8.8 % of cows, 9.3 % of cows, 2.7 % of quarters; (ii) 17.4 % leads to 8.6 % of cows, 10.2 % of cows, 3.9 % of quarters; and (iii) 9.1 % leads to 15.6 % of cows, 13.7 % of cows and 4.5 % of quarters, respectively. Mean cell content of the three first and last cell counts were (i) 380.000 leads to 260.000 (ii) 310.000 leads to 280.000 and (iii) 250.000 leads to 260.000 cells/ml, respectively. The effect of teat-dipping with iodophore solution on the iodine content of bulk milk was investigated simultaneously in the above herds at monthly intervals. A further 26 herds (iiii) which did not employ iodine-containing teat-dips, were also studied. The mean iodine contents for the groups were (i) 127 mug/l, (ii) 152 mug/l; (iii) 94 mug/l and (iiii) 89 mug/l. The effect of teat-dipping with iodophore solution on the iodine content of bulk milk was also investigated in 13 herds where all delivered milk was examined for iodine content during 3 successive 14-day periods, namely (a) a control period without teat-dipping, (aa) a period using a weak iodine solution (0.1 % active iodine), and (aaa) a period using the recommended concentration. The mean iodine content in the 13 herds during period (a) varied from 14 to 266 mug/l and the mean for all herds was 65 mug/l. Corresponding figures for period (aa) were 30--291 and 88 mug/l and for period (aaa) 66--404 and 146 mug/l.