When it comes to mastitis, heifers are often overlooked. But that’s a mistake, since 75% of heifers have some form of clinical mastitis, Dr. Steve Nickerson said Friday at World Dairy Expo.
Nickerson, professor of dairy science at the University of Georgia and a specialist in bovine mastitis, said heifers frequently get mastitis though naturally occurring bacteria that lives on their bodies, especially on their teats. The bacteria enter the teats openings, spreading to cause mastitis.
But flies also play a major role in heifer mastitis. Horn flies are particular problems. The flies not only pester heifers by feasting on blood drawn from animals’ backs but also suck blood from vessels in the skin of teats, causing irritation. That can cause lesions that quickly transform a healthy udder and teats into areas covered in scabs. Once the bacteria spread into the teats, intramammary infection and tissue scarring are likely to result in the still-growing heifers.
Flies also are vectors for transmitting mastitis-causing bacteria. Staph. aureus is a major problem among heifers, Nickerson said.
Treatment can be highly successful, but prevention is key, he added. Some sort of fly control should be employed, especially during the summer months when fly populations are at their peak.
Fly control can be achieved through ear tags, pour-ons, sprays or insect growth regulators, and should be combined with a proper integrated pest management program.
“Herds with fly control programs have much lower levels of mastitic heifers,” Nickerson said.
When heifers are allowed to freshen free of mastitis, lower somatic cell counts and maximum milk production are likely to result.
Central Life Sciences sponsored Friday’s session.