Ring test in milk samples preserved with Bronopol

This study evaluated if the milk ring test (MRT) used to the brucellosis diagnostic at dairy herd level can be done in milk samples with conservative (Bronopol (R)) collected to the somatic cell count (SCC) that is used to mastitis monitoring. It were analyzed 38 bulk tank milk samples (BTMS) from 19 dairy herds artisanal cheese producers and 36 BTMS from a brucellosis free dairy herd, used as negative control (NC) and positive control (PC), when was added serum from vaccinated animals. The milk samples were collected in two different bottles (with or without Bronopol (R)). All the 38 BTMS from artisanal cheese producers (samples with and without Bronopol (R)) were non-reagent to MRT, as all NC. All PC were reagent to MRT, without interference of Bronopol (R). Results showed that the milk sample used to SCC presented the proportion of agreement of results in all milk samples (100%), that is, false positive and false negative results were not observed. Results indicated that Bronopol (R) did not interfere with the color in the time of MRT reading suggesting that the same milk samples could be used to monitoring mastitis and brucellosis.