Bovine Johne's Disease
BOVINE JOHNE’S DISEASE
Mr RIXON (Lismore) [5.28 p.m.]: I bring to the attention of the House the dilemma faced by cattle breeders in dealing with the possibility of their cattle herds contracting Johne’s disease. While sheep breeders are also concerned about the disease it should be clearly understood that Johne’s disease in sheep and cattle are different and should not be confused with one another. However, it is believed that goats, alpaca and deer could become infected with and spread either strain. Johne’s disease causes cattle to scour, that is, develop diarrhoea and lose condition. That results in a drop in milk production, the cessation of reproduction, and the cattle eventually die. Cattle may appear to be active and have a good appetite while wasting away.
Johne’s disease is spread through faeces, direct from mother to calf when suckling from a dirty udder, or to cattle of any age from contaminated pastures. The disease, which is caused by the mycobacterium paratubercalosin bacteria, has a long incubation period in cattle which usually show no signs of the disease until they are four years or older. There is no cure for the disease and vaccines are not very effective. Infected cattle look healthy in the early stages and often do not react to diagnostic tests. The bacteria can survive in cool, sheltered and moist environments, so contaminated land can be a risk to calves and weaners. Currently in New South Wales it is believed that 4 per cent of dairy herds and 0.5 per cent of beef herds are infected, with a greater percentage in Victoria and Tasmania, while Queensland, which is believed to be free of the disease, has adopted protected area status.
Because protected area status has been adopted in Queensland restrictions are being placed on the movement of stock into Queensland and to the Brisbane show, which will be held in August. An example of the difficulty is the problem being faced by Doug Bennett of the Little Valley Braford Stud at Stratheden, who won both the senior grand champion Braford male and female at the Brisbane show in 1996. As much of his stud stock is sold in Queensland, the show and the ability to sell in Queensland are important to him. The stock going to the Brisbane show this year from New South Wales may be segregated from Queensland stock, thus reducing their exposure to potential customers. To do that the cattle must be blood tested as negative. Doug Bennett, using his local veterinarian, Ross Sillar, has to pay $17, which, after a $5 rebate, reduces the cost to $12 per animal tested.
The market assurance program is being developed nationally to accredit tested herds as being not infected with Johne’s disease and as being a safe source for purchase of breeding stock. Currently about 170 herds are enrolled in the market assurance program, which blood tests the herd three times with 12-month intervals between tests. When enough herds in a region have been tested negative, that region will be given protected area status. Producers will know they could buy breeding stock from that area with confidence.
As yet testing is not a perfect science, with an expected 1 per cent incorrect result from blood testing. The enzyme-linked immunosorbent assay blood test is used to establish a herd’s probable disease status. One positive test in 100 tests means a probability of no infection, while 50 positive tests in 100 means a high probability that the herd is infected. Cultures grown from gut material obtained after slaughter will then confirm or negative an infection. Currently the Department of Agriculture veterinary laboratories carry out diagnostic testing on a limited basis free of charge, but further tests must be paid for. However, there is provision for breeders enrolled in the accredited national market assurance program to have testing done for between $6 and $3, but farm blood collecting and transport costs could increase that figure. Doug Bennett expects that the full three-test program on his herd of 250 cattle could cost about $10,000 over three years. That cost is quite high in today’s climate of very low cattle prices.
A number of protocols are still to be thought through to ensure that stock remain free from infection. Straying stock, use of cattle dips by a number of properties, saleyards and showgrounds are all possible routes of infection. More research must be done into the provision of improved testing, protocols for eradicating the disease, protocols for preventing re-infection or infection of clean areas, protocols for showing cattle in New South Wales and interstate, and, importantly, ways of keeping costs to the cattle industry of eradicating the disease as low as possible. I seek the special consideration of the Minister for Agriculture of this complex issue.
Mr AMERY (Mount Druitt - Minister for Agriculture) [5.33 p.m.]: I acknowledge the well-researched contribution of the honourable member for Lismore and his concern for the cattle producers whose herds are affected by the bovine Johne’s disease. The control of Johne’s disease in cattle in this State is an excellent example of cooperation between industry and the Government. The priority in New South Wales is realistic, that is, to limit the further spread of the disease. It is widely acknowledged that eradication from individual herds is difficult and may not be cost-effective. Provided further spread is stopped, it is believed that eradication from the whole industry is not justified in the short to medium term. New South Wales continues to support the national market assurance program to promote the trade in cattle that are free of Johne’s disease. Since the market assurance program was developed by a national industry-based steering committee in May 1996, its uptake by producers in New South Wales has been very encouraging. Even though the disease is recognised as being less common in New South Wales than in Victoria or Tasmania, more than 97 per cent of producers who have enrolled in this national program come from this State.
The initiative of the Government in making available more than $2.3 million from the Cattle Compensation Fund to subsidise testing under the market assurance program has been acknowledged by cattle producers in their commitment to the program. During this financial year New South Wales Agriculture will spend $310,000 on bovine Johne’s disease control, on staff salaries, on-costs and laboratory tests. Rural lands protection boards contribute $200,000 per year in staff time. Controls within New South Wales are being tightened to ensure infected cattle are not sold for restocking. I will take on board what the honourable member for Lismore has said about the impact of the disease on the Brisbane show. I will also reply to him in more detail when I have more time about his concerns about the stud breeder who was having some difficulty in moving his stock across the State line. Interstate movement controls are being reviewed in consultation with industry to develop more realistic cross-border arrangements based on vendor declarations.