22 March 2002

Lepto jabs fail to assist conception

LEPTOSPIROSIS vaccination at 12-15 months of age may be too late to prevent bulling heifers suffering low conception rates.

According to vaccine maker Pfizer Animal Health vet Georgia Owen, research on 10 UK herds vaccinating against leptospirosis revealed that half their heifer groups had already been exposed to infection by 12-15 months.

Colostrum from vaccinated dams gives heifers some protection at first, but this only lasts for three or four months, she told the meeting.

"Then stock are prone to infection if they come into contact with it, although they may not show signs." &#42