Stephen Ward/Oregon State University
Cows that produce milk early are more prone to develop mastitis, but this susceptibility can be detected with a blood test and countered with nutritional supplements, according to an animal scientist.
Gerd Bobe, an associate professor at Oregon State University, studied about 160 pregnant cows several weeks before they gave birth to calves, comparing those that eventually developed mastitis with those that didn’t.
Carbohydrates associated with milk production, such as lactose, usually did not appear in a cow’s blood until a few days before calving, he said.
Cattle that developed mastitis, however, had these metabolites in their blood three weeks before calving, indicating they’d begun producing milk early.
Also, cows don’t usually lose weight from muscle and calf loss before calving, but those susceptible to mastitis started breaking down those tissues earlier, as evidenced by amino acids in their blood.
This “catabolic process” makes less energy available for the bovine immune system to fight off infection.
Aside from supplements to help these cows’ immune systems, milking them before they calf could reduce the risk of infection by taking away the food source from pathogens, Bobe said.
“Also, there is less pressure in the mammary gland, which can cause damage to the tissue,” he said.
By taking preventive steps before the cow becomes infected with mastitis, the dairy producer can avoid treating the udder infection with antibiotics and generating unusable milk, he said.
Preventing unnecessary antibiotic use would have the added benefit of reducing the pressure on pathogens to build up a resistance to the drugs, Bobe said.
The ability to produce milk for a longer period of time also leaves the cow more vulnerable to pathogens, which is particularly true with older animals that are more prone to inflammation, he said.
Bobe hopes the dairy industry can use his findings to develop a simple test that would enable dairy farmers to quickly identify cows that would benefit from preventive treatments.
Reducing mastitis would also decrease the need to cull cows that suffer from chronic infections, he said.