DISCARDED lead batteries from tractors and dozers have become ticking time bombs for cattle producers, with as many as 15 cattle properties in Queensland alone currently unable to sell cattle for slaughter due to lead poisoning issues.
Despite regular warnings about the risks posed to livestock and overseas markets when cattle are exposed to sources of lead, such as old batteries, machinery or dumps, the message does not appear to be getting through.
One property near Roma lost several cattle after they were exposed to lead from two bulldozer batteries left in a paddock.
The producer has since had to repeatedly test more than 100 “at risk” cattle at a cost of $35 per animal for the past two years, with some animals still yet to be cleared for slaughter.
Another property in Queensland has 600 at risk cattle undergoing similar testing following lead poisoning after accessing batteries in a paddock.
The costly but preventable problem remains all too common throughout the cattle industry, a frustrated Biosecurity Queensland veterinarian David Pitt told Beef Central this week.
Cattle are attracted to the taste of salt in batteries where lead has been exposed or in flaking lead-based paint.
It is a fatal attraction, with lead highly toxic to cattle.
The first sign of exposure is usually the discovery of dead stock or blind cattle walking aimlessly into fences and other obstacles.
Cases are typically diagnosed by private vets after symptoms appear or cattle die. Affected herds are then excluded from slaughter and placed under the supervision of departmental officers, who then identify other “at risk” stock exposed to the same source of lead and implement a testing regime.
Blood testing of ‘at risk’ animals will lead to cattle being classified either as PB1, which means they are marked in the NLIS database as excluded from slaughter; PB2, which means they can be slaughtered but their liver, kidney and offal is condemned; or clear, where lead levels are determined within acceptable levels.
“At any one time I have around 15 properties with restrictions on them,” Dr Pitt told Beef Central.
An analysis of 20 years of records in Queensland showed a higher prevalence of lead levels in areas west and north of Toowoomba, where many properties have integrated cattle and cropping operations.
However cases occurred anywhere cattle and machinery were found together, Dr Pitt said, with recent cases recorded in South East Queensland, Central Queensland and North Western Queensland.
“In 99pc of cases it is an old battery,” Dr Pitt said.
“Usually it is caused by batteries in old tractors left in the paddock, cattle find them pretty quickly, or an old dump site in a gully.
“When a flood or a fire goes through, it exposes old dump sites that have been buried.
“We also had one recent case of an old van painted in lead and with many lead parts; cattle were just licking and chewing that.”
There are a number of steps producers can take to minimise the biosecurity risk. This starts with maintaining effective fences so livestock don’t have access to farm dumps, and disposing of old batteries and chemical drums at an authorised depot.
As well as in vehicle batteries, lead can be found in discarded sump oil, building materials, lead-based paint, old paint tins, linoleum, grease, putty, oil filters and a range of other sources.
Despite the issue at farm level, there is no evidence that lead poisoning issues have caused higher lead residues in the supply chain.
Close to 6000 random tests are conducted through the National Residue Survey at export and domestic abattoirs each year, funded by industry levies, analysing muscle, fat, blood, organs and other animal tissues.
Random samples are routinely screened for a wide range of contaminants, including antibiotics, hormones, anthelmintics and other veterinary drugs, plus fungicides, herbicides and insecticides and environmental contaminants such as heavy metals, including cadmium and lead.
Last year, while there were some traces of lead found in 124 liver samples, these were in minute concentrations, only a fraction of the MRL Australian standard of 0.5mg/kg.
To discuss with Dr Pitt or another Biosecurity Queensland officer any issues relating to Lead (Pb) contact the DAF Biosecurity Queensland customer service centre contact 132523 (local call rate).
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