Clinical Mastitis in Norwegian Herds After a Combined Selective Dry-Cow Therapy and Teat-Dipping Trial

Abstract

The objective of this study was to see if introduction of a 2-yr combined selective dry-cow therapy and teat-dipping trial would reduce clinical mastitis (CM) events in 164 Norwegian dairy herds. Three different penicillin or penicillin/dihydrostreptomycin-based dry-cow treatments, and 3 different teat-dipping regimens (negative control, iodine teat dip, or an external teat sealant) were independently and randomly allocated to each herd. Complete lactations both before and during the trial were investigated. Altogether, 1,005 CM cases were recorded in the lactations before the trial and 924 cases were recorded during the trial. Bacteriological milk samples were available from 784 of the 924 CM cases during the trial. Among these, Staphylococcus aureus were isolated from 47.4%, Streptococcus dysgalactiae from 22.5%, Escherichia coli from 10.7%, and coagulase-negative staphylococci from 6.3%. In addition, 12.5% cases were bacteriological negative, and the remainder of the CM cases were caused by other microbes. The different models were analyzed using Cox regression analysis with PROC PHREG and a positive stable frailty model in the SAS macro. Separate models were made for cows housed in tie-stalls and free-stalls. Parity had a significant impact on the CM risk in both type of stalls. Older cows (parity > 3) had the highest hazard ratio of contracting CM in tie-stalls (1.68) and free-stalls (2.18) compared with parity 1. The CM risk decreased significantly (13%) in tie-stalls and by 18% in free-stalls. In tie-stalls, iodine-dipped cows had a significantly lower chance (21%) of getting CM compared with the negative control and the use of external teat sealant. The same trend was seen in free-stalls; however, the differences were not significant. Compared with CM before the trial, the reduction of CM was 15% during the trial.

PCR-SSCP and Sequencing of CXCR1 (IL8RA) Gene in Indian Water Buffalo

“…In all housing systems, high stocking density, dirty bedding or ground, infected utensils, poor ventilation and high humidity were important risk factors (Sudhan and Sharma, 2010).While looking on the animal associated determinants it has been found that increasing parity increased the risk of mastitis in buffaloes. Other reports were similar with the current findings (Kumar and Sharma, 2002;Sharma and Prasad 2002;Whist et al, 2006;Kavitha et al, 2009).…”

Molecular Types and Genetic Profiles of Staphylococcus aureus Strains Isolated from Bovine Intramammary Infections and Extramammary Sites

“…Postmilking teat dipping, practiced for both herds, did not appear to prevent the growth of S. aureus on the teats. The efficacy of the teat dips may not be as good under field conditions as under experimental conditions, as recently shown in a Norwegian field study (49). In herd II, extramammary sites may be more likely routes of transmission than milk from infected quarters.…”

Sources of Contamination of Bovine Milk and Raw Milk Cheese by Staphylococcus aureus Using Variable Number of Tandem Repeat Analysis

“…More surprisingly, in herd B, two genotypes [13,17] present in the nasal cavities of the sampler, external to the farm, were also present in the quarter milk sample, one of which was also found on the teat skin. In the latter case, the sampler was most likely the origin of the contamination of the samples.…”

“…It is always difficult when evaluating the effectiveness of the teat dipping to determine what is attributable to the practice or to the products or to the manner in which the teat dipping is applied. It has been reported that the conventional cleaning of udders with wipes was very effective in eliminating S. aureus present on the teats as opposed to pre-teat dipping [16] and that post-teat dipping also had limited effectiveness [17]. The only herd not practicing pre-dipping of teats (herd D) had the lowest rate of cows infected with S. aureus.…”