Presented at the 2nd Panamerican Congress of Milk Quality and Mastitis Control
2002 November 25-27
The epidemiological research of bovine mastitis has demonstrated that 30% to 50% of new intramammary infections (NIMI) occur during the dry cow period (1). The susceptibility of the mammary gland is greater during the active involution period and calostrum genesis, in which the most part of the NIMI are produced by major infectious and environmental pathogens respectively. During the involution period antibiotic therapy has been successful in reducing the rate of NIMI approximately 50%. During the second half of the dry period a second antibiotic therapy generally intravenous (1) and more recently dry cow teat sealant (2) with or without germicide have been tested. In Argentina intensification of milk production systems has lead to an increase in post partum NIMI rate and clinical mastitis due to environmental pathogens especially Streptococcus uberis, Strep. dysgalactiae and Coliforms.(3)
The objective of this study was to evaluate the persistence and effectiveness of a teat sealant (DryFlex TM, DeLaval Inc.) applied in pre-partum dairy cows in a grassing system.
Material and Methods
Test 1: Evaluation of the persistence of the teat sealant on adult pre partum Holstein cows in grassing condition. A total of 17 cows were evaluated. The first application was carried out 10- 12 days before the estimated calving date. Each teat was qualified according to a visual scale where 5 is complete coverage of the teat and 1 is complete loss of the product, tabulated daily.
Test 2: Evaluation of the effect of DryFlex application on the prevalence of clinical mastitis, modification of bacteria etiology and evolution of the SCC/ml. A total of 108 Holstein cows and heifers, paired by number of lactation, calving date and with no records of clinical mastitis in the previous lactations, were randomly assigned to a Treatment Group (T, n=49) and a Control Group (C, n=54). All adult cows have been dried at the end of lactation with Mamyzin S (Boehringer Ingelheim).. The application of DryFlex began 7 days before the estimated calving date and the cows were checked every 4-5 days. The teats that lost the film completely were treated with the product again. This experiment was conducted during a period of abnormal high rainfall, mud and flooding. During the subsequent lactation, animals in both groups were properly identified and equally handled in feeding and milking. Cows were forestriped, and pre and post dipping with a 0,25% iodine teat dip (Della Pro, DeLaval Inc). During the first 45 days of lactation, every case of clinical mastitis was registered and analysed following the IDF recommendation (4). Samples for SCC were taken during the milk control on a monthly basis. SCC determination was made with Fossomatic (Foss Electric Denmark) according to the FIL.IDF 148 A: 95 norm. Chi square test was used for analysis of complete and partial prevalence of clinical mastitis cases, according to type of bacteria. The SCC/ml was analysed according to Student’s T test and analysis variance by using The Statistix, Version 3.5 software (Analytical Software, St. Paul, MN, USA) and BMPD (Statistical Software ,Los Angeles, USA).
Results and Discussion
Test 1: Persistence of teat covering between days 4 and 5 after application was of 50%, which his consistent with other reported results. If the teats, at the time of application, were clean and dry, the adherence will not be affected by intense rainfall or muddiness.
Test 2: Pre-partum application of DryFlex is shown to reduce SCC and new cases of clinical mastitis during the first 45 days post partum. SCC was reduced at 14 days psot partum and significantly reduced at 45 days. NIMI was significantly reduced for DryFlex treated cows compared to the controls. It was especially effective against Environmental Strepts. and Coliforms. No differences were observed in the cases of clinical mastitis produced by Staphylococcus aureus.
||SCC/ml x 1000(Average)
||(% of cows)
||Strept. (% of cows)
||(% of cows)
||419.2 (aa) +- 162.9
||367.2(A) +- 132.9
||328.1 (bb) +- 98.6
||123.9(B) +- 24.5
a,b-significantly different p<0.05 Chi Square aa,bb- significantly different p<0.1 T test; A,B-significantly different p<0.01 T test
Previous results have shown that Dry Flex is effective at reducing dry period NIMI when used in combination with dry cow antibiotic and applied at dryoff and pre-partum. (2) The current study shows a strong benefit of the external teat sealant when applied pre-partum only. It is expected that the concentration of dry cow antibiotic in the gland would be below the MIC during the prepartum period and the udder would be at its most susceptible state. The use of DryFlex is shown to provide protection during this period and results in improved udder health during the next lactation.
Dupuy, J.; Corbellini, C.N.; Micheo, C.R.; Garbarino, E. - 2001 - La etiología de las mastitis de un rodeo determina la estrategia de control, Tesis de Graduación, Facultad de Ciencias Veterinarias, Universidad Nacional del Centro de la Pcia. De Bs. As., 42 pp, Tandil, Argentina, Mayo 2001.
International Dairy Federation - 1981 - Laboratory Methods for use in mastitis work, Document 132, FIL-IDF, Brussels, Belgium
Timms, L.L. - 2001 Assessment of closure of the teat streak canal after drying off, pp. 209-210 In: National Mastitis Council Annual Meeting Proceedings, NMC, USA.
Ziv, G. - 1995 - Treatment of Mastitis: An overview of Progress during the last ten years, pp.3-12, Book II In: Proceedings of the 3rd. International Mastitis Seminar, Ed. by A. Saran and S. Soback, Tel-Aviv, Israel, 28 May-1 June 1995.