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United States Department of Agriculture

Agricultural Research Service

Title: Destruction of Mycobacterium Paratuberculosis, Salmonella SPP., and Mycoplasma Ssp. in Raw Milk by a Commercial on Farm High Temperature, Short-Time Pasteurizer

Authors
item Stabel, Judith
item Hurd, Howard
item Calvente, S - IOWA STATE UNIV
item Rosenbusch, R - IOWA STATE UNIV

Submitted to: Journal of Dairy Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 26, 2004
Publication Date: July 1, 2004
Citation: Stabel, J.R., Hurd, H.S., Calvente, S., Rosenbusch, R.F. 2004. Destruction of mycobacterium paratuberculosis, salmonella spp., and mycoplasma ssp. in raw milk by a commercial on farm high temperature, short-time pasteurizer. Journal of Dairy Science. 87(7):2177-83.

Interpretive Summary: Morbidity and mortality in neonatal calves is a major concern for dairy producers. Evidence suggests that calves can become infected shortly after birth by exposure to pathogens such as Mycobacterium paratuberculosis, Salmonella, and Mycoplasma in either the feces or milk of infected dams, bedding or cohabitation with other infected animals. These pathogens may be spread to calves through waste milk from sick cows. Some producers have opted to feed milk replacer to their calves to avoid the potential spread of disease. However, this is an additional expense that some producers cannot afford. Pasteurization of waste milk is an economical alternative to commercial milk replacers, however, little is known about its effectiveness in destroying these pathogens. This study demonstrated that a commercial pasteurization unit designed for on-farm use was successful in completely destroying selected pathogens added to the milk. This information provides a useful management tool for dairy producers in allaying the spread of infectious disease to their replacement animals. Technical abstract: The 2002 NAHM's Dairy Survey indicated that 87.2% of dairy farms in the US feed waste milk to their neonatal calves. Although cost-effective, this practice can lead to increased calf morbidity and mortality due to ingestion of pathogenic agents. In an effort to reduce the risk of infection, dairy producers are implementing on-farm pasteurization of the waste milk as a control procedure before feeding the milk to calves. In the present study, we evaluated the efficacy of a commercial high-temperature, short-time (HTST) on-farm pasteurizer unit to destroy Mycobacterium paratuberculosis, Salmonella enterica spp., and Mycoplasma spp. in raw milk. Replicate experiments were run for 3 isolates of M. paratuberculosis, 3 serovars of Salmonella (derby, dublin, typhimurium); and 4 species of Mycoplasma (bovis, californicum, canadense, serogroup 7) at two different levels of experimental inoculation. In addition, HTST pasteurization experiments were performed on colostrum experimentally inoculated with M. paratuberculosis. After culture of the pasteurized milk samples, no viable M. paratuberculosis, Salmonella or Mycoplasma were recovered, regardless of species, strain or isolate. Pasteurization of colostrum was also effective in the destruction of M. paratuberculosis but resulted in a average 25% reduction in colostral immunoglobulin. These results suggest that HTST pasteurization is effective in generating a safer product to feed to young calves.

Technical Abstract: The 2002 NAHM's Dairy Survey indicated that 87.2% of dairy farms in the US feed waste milk to their neonatal calves. Although cost-effective, this practice can lead to increased calf morbidity and mortality due to ingestion of pathogenic agents. In an effort to reduce the risk of infection, dairy producers are implementing on-farm pasteurization of the waste milk as a control procedure before feeding the milk to calves. In the present study, we evaluated the efficacy of a commercial high-temperature, short-time (HTST) on-farm pasteurizer unit to destroy Mycobacterium paratuberculosis, Salmonella enterica spp., and Mycoplasma spp. in raw milk. Replicate experiments were run for 3 isolates of M. paratuberculosis, 3 serovars of Salmonella (derby, dublin, typhimurium); and 4 species of Mycoplasma (bovis, californicum, canadense, serogroup 7) at two different levels of experimental inoculation. In addition, HTST pasteurization experiments were performed on colostrum experimentally inoculated with M. paratuberculosis. After culture of the pasteurized milk samples, no viable M. paratuberculosis, Salmonella or Mycoplasma were recovered, regardless of species, strain or isolate. Pasteurization of colostrum was also effective in the destruction of M. paratuberculosis but resulted in a average 25% reduction in colostral immunoglobulin. These results suggest that HTST pasteurization is effective in generating a safer product to feed to young calves.

Last Modified: 4/16/2014