More than 90% of herds, and about 65% of cows, were positive for liver fluke in 250 beef herds investigated by Teagasc in the 2014/2015 winter for exposure to liver fluke.
And when 169 spring calving, non-vaccinating suckler cow herds were investigated in the 2014 and 2015 summer months, exposure to Leptospirosis and BVD was found in 70-80%of herds.
Farmers attending last week’s Beef 2016 event at the Teagasc Animal & Grassland Research and Innovation Centre, Grange, Co Meath, were told infectious agents can damage suckler cow fertility by increasing embryo mortality and in particular, abortion.
Bacterial agents remain the primary cause of bovine abortion in Ireland, and liver fluke can exacerbate the impact of bacterial infections.
Preliminary findings from the summer study of 169 suckler cow herds with almost 6,000 cows reveal exposure to Leptospira species in 71% of the herds, BCD virus in 78%, the bovine Herpes virus (which causes IBR) in 44%, and Neospora caninum in 5%.
Leptospira and Neospora caninum, along with Salmonella dublin, have been the most common infectious causes of abortion since 2008, in foetal examinations by the Regional Veterinary Laboratories.
(Arcanobacterium pyogenes and Bacillus licheniformis were also linked to significant levels of abortion, but these tend to occur more sporadically, with B licheniformis thriving in spoiled feed and forage).
Although not a direct cause of abortion, liver fluke can exacerbate the impact of certain infection disease, such as salmonellosis.
The 250 beef herds investigated for exposure to liver fluke were selected on the basis of location and herd size to best represent the distribution of beef herds nationally.
Antibody testing of 6-7 cows in each herd was carried out, and the very high levels of liver fluke exposure detected point to the need for better fluke control on farms.
At Beef 2016, vaccination, biosecurity and diagnostics were highlighted as the critical components in achieving control of infectious diseases on beef farms.
Biosecurity is the single most important contributor to prevention of infectious diseases and subsequent losses on a farm. The more disease, the stricter the biosecurity measures required.
A strict closed-herd policy is critical (no cattle movement, including bulls, on to the farm), in order to block direct importation of disease onto a farm.
Beef farmers should also maintain, as much as is practically possible, stock-proof and disease-proof boundaries (a 3m gap from neighbouring farms to avoid nose-to-nose contact).
Footbaths should be used, cleaned and re-filled regularly. Signage should maintain awareness of biosecurity.
Separate disposable needles should be used for each animal when administering medications or taking samples. Separate rectal sleeves should be used when scanning, examining or treating cows.
Importation of animal products (slurry, colostrum) should be avoided.
Vehicles visiting the farm should be kept at a safe distance from animal housing, holding yards, roadways.
Farmers at Beef 2016 were told the usefulness of diagnostic testing on Irish beef and dairy farms is often underestimated, and many beef farms have no routine herd health screening other than routine annual screening for TB and BVD.
Use of sentinel animals (indicator animals, tested at least annually) can be useful for detecting changes in herd disease status.
In contrast, it seems the uptake of vaccines by Irish farmers is much greater than uptake of either biosecurity or diagnostic testing.
Vaccines play a hugely important role. However, not having the supporting knowledge from diagnostic testing, or a biosecurity plan, could potentially undermine the effectiveness of vaccines in disease control.
Misuse of vaccines is also significant: instructions must be read in their entirety, and the number of injections administered, dosage, and correct vaccination timing adhered to.
Over-reliance on vaccination, without proper management, biosecurity and diagnostics should be avoided.
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