Ed Pomeroy has been a dairy producer near Custer, Wash., for the past 48 years. Two years ago, a baffling health problem in his herd’s fresh cows was diagnosed as a Salmonella infection. “We were having quite a lot ofproblems with fresh cows,” he says. “Cows would sicken and die and we couldn’t figure out what was really going on until we finally narrowed it down to Salmonella.”

 

It was the first time the closed dairy, consisting of 2,250 milking and dry Jersey cows, had experienced anything like this, explained Pomeroy. “We’ve been a closed herd for at least 20 years or more,” he says. “We raise all our own replacements. There aren’t any animals on the dairy that haven’t been born here. We’ve expanded from 300 to 2,250 with justour own replacements.”

 

Pomeroy says the source of the Salmonella outbreak on the farm is still a mystery, but he believes that the disease is now under control.He attributes this to regular use of a vaccine from AgriLabs that he decided to try after hearing good reports about it from others.  “We put all our cows on the vaccination program and after a month or two, we could see results. Occasionally we still have a problem, but it’s been a big improvement over what we were seeing before.”

 

The AgriLabs vaccine he is using is Salmonella Newport Bacterial Extract with SRP® technology. SRP vaccines are made from siderophore receptors and porins (SRP), which are specialized proteins found on the cell wall of Salmonella bacteria. They are similar on all strains of Salmonella. Among other things, SRP vaccines stimulate the production of antibodies that block the siderophore receptors and porins on the cell wall of the disease-causing salmonella bacteria in the animal. This deprives the bacteria of iron, and causes it to die.

 

Pomeroy says he is continuing use of the SRP vaccine in an annual  Salmonella vaccination program. This protocol calls for vaccination of all cows and bred heifers twice before calving. Even though the dairy industry overall is suffering in the current economic environment, and is not as profitable as it has been, Pomeroy doesn’t believe I t is cost-effective to eliminate animal health programs such as the SRP vaccine. These disease control programs are effective and contribute to improved production efficiencies in the long run, he says.

 

“I usually continue to do the things that work for my dairy whether times are good or bad. In the case of Salmonella, “I don’t want to have a big cluster of problems again, so I’ll just continue with the SRP vaccination program.” 

• Cattle inoculated with Salmonella Newport vaccine produced significantly more milk (2.51 pounds per day) in the first 90 days of lactation, compared with cattle injected with a control solution.

• Cows vaccinated with SRP had a statistically significant lower somatic cell count during one of the measured time points.

 

The KSU study is the first formally published study to provide evidence that vaccinating cattle with Salmonella Newport SRP vaccine improves milk production in a herd without clinical signs of salmonellosis. These results areconsistent with multiple unpublished field and clinical trials showing similar results. In the study, the cows were randomly assigned to receive Salmonella Newport SRP vaccine or a control treatment. Vaccine or control solution was injected 45 to 60 days before parturition, and cattle received a second dose 14 to 21 days before parturition.

 

Milk production was monitored for the first 90 days of lactation. Feces for isolation of Salmonella and blood   samples for detection of antibodies against Salmonella Newport were collected at day of first injection and at days 7 - 14 and 28 - 35 of lactation. Although the study showed positive results, the researchers involved agree that more research is needed to clarify the mechanisms by which productivity was improved.