The state Department of Agriculture is urging ranchers statewide to adjust their livestock management practices to reduce the chance their cattle will spread disease.

The initiative follows an outbreak of E. coli infection on Kaua'i in March, which state Department of Health investigators believe is linked to floodwater flowing from a contaminated pasture onto a lettuce farm.

The E. coli bacterial infection hospitalized four tourists and sickened four other people. All eight have since recovered.

"If animal manure is not properly contained or treated, it can lead to waterborne and food-borne illnesses," state veterinarian Dr. James Foppoli wrote in a letter to Hawai'i's livestock producers.

Hawai'i cattle ranchers said they believe most ranchers already use practices that minimize problems.

"It just makes sense from all the different aspects — environmental, business and the health of the animals," said Tim Richards, a veterinarian and president of Kahua Ranch.

Foppoli said contamination can occur when livestock-contaminated water is used for crop irrigation or the washing of produce, when flooding carries contamination into crop areas, and when improperly aged or treated manure is used to fertilize fruit or vegetable crops.

E. coli isn't the only culprit, he told ranchers. Other public health pathogens include cryptosporidium, salmonella, campylobacter and other agents. They may not harm adult animals, but can cause disease in humans and sometimes in young animals.

The Department of Agriculture is pointing ranchers to a publication by Louisiana State University, "Beef Production Best Management Practices," which is now listed on the department's Web page, www.hawaii.gov/hdoa.

Among the recommendations are to provide cattle with clean stock water, treat diarrhea in cattle and prevent cattle from contaminating waterways. Among techniques for protecting streams are to fence cattle away from them and to provide ungrazed buffer zones between pasture and waterways.

STEPS TAKEN

Such precautions are already in place in many pasturing operations, said Donn Carswell, president of Princeville Ranch on Kaua'i.

"That's what we've been doing for years," Carswell said.

"The good managers are doing that," said Jimmy Greenwell, former president of the Hawai'i Cattlemen's Association.

Richards and Greenwell both agreed with Foppoli that one area of concern might be high-density cattle operations that produce a great deal of manure in a small area, particularly if that manure is used to fertilize crops.

State epidemiologist Dr. Paul Effler said that while Kaua'i is implicated in the most recent outbreak, O'ahu commonly has the state's highest number of cases due to its large population, and the Big Island historically has a higher rate of E. coli cases due to its large number of cattle.

Reach Jan TenBruggencate at jant@honoluluadvertiser.com.