Dairy Initiatives

Dairy

Department of Animal Science

D A I R Y   I n i t i a t i v e s   N E W S L E T T E R
V o l u m e   9      I s s u e   1     Winter   2 0 0 0

America's Least Wanted

These three thieves are out to destroy your farm. Can you help stop them?

Three infectious diseases--Johne's disease, bovine viral diarrhea (BVD), and Salmonella--cost Minnesota dairy farmers millions of dollars each year in lost productivity, premature culling, preventive and treatment costs, and animal deaths. In the future, they may even lead to lost ability to sell products from your farm. How can you keep them from ruining your operation?

Your first job is to keep these profit-robbers off your property. If they do break in, you need to keep them from spreading to healthy animals.

After you've read the "Un-Wanted" posters below, take a good look at your operation. What practices can you change to reduce the risk of disease in your herd?

JOHNE'S DISEASE

BOVINE VIRAL
DIARRHEA
(BVD)

SALMONELLA

TRICKY TRAITS:  
The microbe that causes Johne's disease can survive for years in the Minnesota environment. An animal can be infected for years before it tests positive or shows signs of illness.

LOOK FOR:  
Weight loss and diarrhea in adult cattle, often a few weeks after calving; a drop in herd milk production.

HOW IT SPREADS:  
From manure to mouth; to calves through manure or milk; sometimes from mother to fetus.

HOW TO AVOID:  
Buy cattle only from herd status program herds.

IF IT'S ON YOUR FARM:  
Test all adult cattle once a year with blood test; follow up blood test positives with fecal culture. Keep calves away from adult cattle and manure, and avoid feeding milk or colostrum from test-positive cows. Consider culling those that culture positive. Don't use calving areas for sick animals. Limit maternity areas to one cow at a time. Don't let manure touch feed or water.

TRICKY TRAITS:  
Cattle infected before birth can give BVD to other animals throughout their lives, even though they never seem sick.

LOOK FOR:
Breeding problems, abortion, calf death. May increase susceptibility to other illnesses.

HOW IT SPREADS:  
From cattle infected before birth (fetuses can get it from their mothers) or recently infected cattle (which usually don't appear sick). Spreads by nose-to-nose contact, sexual contact, or through urine or manure.

HOW TO AVOID:  
Only bring cattle onto your farm from known uninfected herds or herds with a good vaccination program. Test new cattle before arrival. Isolate new animals for 30 days.

IF IT'S ON YOUR FARM:  
Isolate sick and infected cattle and handle last when doing chores. Use disinfectant. Keep calves in hutches. If you suspect a problem, test cattle (including calves) as directed by your veterinarian and cull if positive.

TRICKY TRAITS:  
An animal can spread Salmonella without seeming sick. Salmonella can survive outside of animals for months.

LOOK FOR:  
Diarrhea, fever, wasting, especially in calves.

HOW IT SPREADS:  
From manure to mouth; to calves through manure or milk; sometimes through dust.

HOW TO AVOID:  
Quarantine new animals. Have visitors who have been on other farms disinfect their boots or wear disposable boots before entering your dairy facilities. Don't bring in manure-contaminated equipment from another farm.

IF IT'S ON YOUR FARM:  
Keep manure and feed separate and handle with separate equipment. Sanitize calf feeding equipment. Don't feed raw milk or colostrum. Keep feed areas clean. Don't spread manure where cows will graze or on roughage you'll feed the same year. Separate sick and healthy cattle. Limit maternity housing to one animal at a time and clean and disinfect between uses. Caution: Salmonella also causes human disease. Wash hands after handling cattle (especially calves) and limit cattle contact with visitors.

D A I R Y    I n i t i a t i v e s    N E W S L E T T E R
Volume 9     Issue 1    Winter 2000