After the glorious, bacon saving rain recently, my colleagues and I have discussed the animal health problems we have seen or expect this autumn.
I understand that much of NSW now has feed and our patch (the Central Tablelands) is wonderfully green. Judy Ellem, district veterinarian (DV) based at Gunnedah said the tropical grasses are now above the windows of the ute and seeding in the north-west.
A small downside is that some of this green is toxic weeds. A farmer recently told me he now has a balanced pasture of cathead and hairy panic. He is not the only one with cathead (Tribulus), a well-known liver toxin that grows prolifically in many areas.
While my colleagues have seen some cases of liver disease and photosensitisation from cathead (and hairy panic) it has not been as severe as expected (yet) given its abundance.
At Forbes, DVs Belinda Edmonstone and Nik Cronin have seen fewer cases than expected under the circumstances. There is speculation that a second factor, perhaps a fungus is involved meaning that both are needed to cause disease.
Portulaca or pigweed, the succulent green weed, is also abundant at the moment. It is both highly palatable and high in nitrates and has caused quite a few cases of nitrate poisoning.
Shaun Slattery, a DV based at Narrabri, commented that most cases have occurred when stock have been trucked or yarded for shearing/crutching then released into a yard or paddock growing portulaca.
Jillian Kelly at Coonamble and Jim Kerr in the Hunter Valley all report that hungry stock have died from nitrate poisoning after consuming portulaca. Jim said that one producer, anxious to avoid potentially toxic paddocks of rapidly growing kikuyu, lost quite a few cows when he put them in a paddock dominated by portulaca.
While my colleagues have seen some cases of liver disease and photosensitisation from cathead (and hairy panic) it has not been as severe as expected (yet) given its abundance.
- Bruce Watt
DVs on the North Coast also report lots of photosensitisation and other plant poisonings.
Jocelyn Todd, based at South Grafton, reports that lantana, bracken fern, rock fern and smart weed are all causing stock losses on some properties, while Ian Poe based at Kempsey, Lisa Martin (Tenterfield) and Lyndell Stone (Wingham) have all seen problems too.
Bovine ephemeral fever (BEF or three-day sickness) the mosquito borne disease of cattle is also spreading down from the north at the moment. The name three-day sickness implies the disease is transient but it makes cattle feel sick and sore and big heavy cattle can stay recumbent.
Ted Irwin, based at Warialda, reports lots of BEF in that area (the first since 2010) and it has been reported at Narrabri, Moree and Gilgandra.
Of interest, it hasn't appeared on the coast yet. Liz Bolin hasn't heard of confirmed cases on the north coast.
Lyndell Stone and Ian Poe have also not heard of cases on the Mid Coast either, but they are expecting it. Lyndell commented that BEF hasn't spread in a monitored herd at Taree for a couple of years so quite a few young cattle will be susceptible. Andrew Biddle (Inverell) comments that being between the Coast and North West, they are like a flat footed inside centre, just waiting for the hit.
Virologist at the Elizabeth Macarthur Agricultural Institute, Deborah Finlaison, expects BEF virus to remain active and spread for the next two to three months, depending on the weather.
It is probably too late for vaccination in some areas, but Lyndell Stone and Megan Davies (Narrabri) are advising cattle producers to consider vaccinating at-risk cattle and bulls if they do so immediately.
