Avoiding risks of pests and diseases

We all do our best to keep our farms free of pests and diseases and our cattle healthy. After Rod got the Biosecurity Farmer of the Year award we have been asked what we do on our cattle stud that is different to what the average farmer does.

Firstly because Rod has a veterinary background we understand the risks better than most. We know how quickly things can go wrong if there are opportunities for it to happen. Most of all we want to reduce risk – we want no surprises. We do more than most farmers to keep these risks and surprises to a minimum.

One disease problem that annoys us is Enterotoxaemia. Since moving to Binda we have lost one animal per year on average. It is always the same scenario, an adult animal (often a cow with a young calf), a good doer, on lush pastures. Lush feed provides the opportunity for the bacteria (Clostridium perfringens) to multiply in the gut and to produce the toxin which kills rapidly. The result is a dead animal found in the paddock. The diagnosis of entertoxaemia is difficult. Talking with friends and fellow cattle producers it seems we get more of these enterotoxaemia deaths than average. Other cattle breeders have cattle die of Grass Tetany or bloat. When Rod asks why are they not Enterotoxaemia deaths the answer is always the same “We vaccinate with 5 in 1″. Rod explains that when you read the small print it says that the vaccine will only protect against Enterotoxaemia for 3 months when conditions are favourable. We had a heifer die from Enterotoxaemia 2 months and three weeks after vaccination but the conditions were ideal. The heifer took a day to die which suggests that there was some, but inadequate, protection. The loss of one good animal a year is a significant loss and justifies us vaccinating at intervals as short as three months. There is an old saying that if you vaccinate against Enterotoxaemia you get fewer deaths from bloat and grass tetany.

Pestivirus is a risk well worth avoiding. It is a complex disease which has been better understood in recent years. Rod was Director of the Veterinary Laboratories at Glenfield and remembers work conducted there in the 1970s when it was called mucosal disease. A persistently infected (PI) heifer infected a whole mob of animals overnight. Rod credits his colleagues, Ian Littlejohns and Peter Kirkland, for world class research which has led to the production of a vaccine and development of accurate tests. Pestivirus can cause major calf losses. The risk is greatest in well managed, closed herds with little outside exposure which can provide some immunity. Although the vaccine is not cheap it provides effective protection in otherwise naive and susceptible animals.

Another other disease risk is when you bring in cattle. We recently introduced 4 stud females (1 cow and calf, 1 pregnant cow and two pregnant heifers) from Victoria, purchased at auction. Before considering whether to purchase we checked the Bovine Johne’s Disease (BJD) status of the herd of origin on the Animal Health Australia website. It was MN3 which is the highest status in the Market Assurance Program which provides a degree of certainty that we will not be buying in problems (but not 100% certainty unfortunately – see later). We had an isolation paddock ready for them. We ran them through the crush so that we could vaccinate them and treat for parasites and lice. We saw that there were many Bathurst burrs attached to their long winter coats. We have no Bathurst burrs on the farm and had no intention of starting now. We spent an hour combing and picking the burrs out of their coats. We found a major site for these burrs to be lodged is between the teats of the pregnant heifers. Luckily they quietened down after a while and submitted to the de-burring. This was time well spent in preventing a problem establishing itself on the farm. We will watch the quarantine paddock for any signs of the troublesome weed pest.

We recently purchased two loads of hay. When we bought hay in the 2006-2007 drought we bought in some barley grass seed which caused two problems. Firstly we have a minor weed problem as a result but more annoying for us were the cattle getting grass seeds in their eyes. Since then we have only bought hay that has a certificate confirming freedom from weeds. We have found Feed Centralhttps://www.feedcentral.com.au/ to be very good. Sellers of hay can get Feed Central to certify hay even if the hay is not sold through them.

The serious weed threat that we face is Serrated Tussock. The Binda / Crookwell district has a severe tussock problem. We had the farm checked out by the local agronomist prior to purchase. (Some farms are so badly affected that it costs more to eradicate Tussock than the property is worth.) Two years ago we had silage made in two paddocks. This year we found a single mature Serrated Tussock plant in one of these paddocks which was mostly native grasses. Because it had seeded we will be vigilant in looking for any seedlings. Furthermore we intend to spray the whole paddock out this season and direct drill perennial grasses. Serrated Tussock we definitely do not want. Next time we get contractors in we will definitely insist on pressure cleaning of their equipment.

Pivotal to our Biosecurity is our record management. We use Cattlelink https://www.herdlink.com.au/ to record our cattle, submit Breed Society registrations, Breedplan data, record weights and scans, health treatments, mob movement, paddocks grazed, NLIS tags, client details, photos etc. It is invaluable. This was proved after we purchased cattle from a MN3 herd in 2004. This herd had a positive BJD cow identified in 2007 but we were not advised until early 2009. It was possible that some of the cattle purchased in 2004 and subsequently sold might have been infected and then infected our cattle. Because the purchased cattle had been sold we could not prove them to be free of infection. The DPI officials were keen that all our cattle be culled. By analysing our cattle records we could identify which of our cattle had contact with the purchased cattle. These we kept isolated and regularly monitored with faecal culture until they were all culled for slaughter. Our other cattle were also monitored six monthly until we threw off the Suspect status. Luckily there was no evidence of BJD in our cattle and we are now MN2.