Livestock Matters - Spring 2018

SPRING 18 ISSUE LIVESTOCK MATTERS 1 2 POOR FERT I L I TY Richard had never had any problems getting cows into calf prior to this. Poor bull fertility can sometimes be the reason for PD-negative cows. But this particular group of cows had all been artificially inseminated by Richard, who was very experienced in the technique. Sam’s immediate plan of action was to check for the presence of infectious diseases and any mineral deficiencies. He took blood samples from a representative group - and also included samples from the two cows which had aborted. Richard always put out general purpose mineral buckets for the herd, and a specific formulation for the dry cows. Reassuringly, test results for copper, selenium and cobalt confirmed levels were normal. Blood was screened for the presence of BVD, IBR and leptospirosis. The results showed the herd was naïve to IBR and BVD. However, there were two positive samples for leptospirosis, which came from the cows which had aborted. Sam explains: “This was evidence that the herd had at some point been exposed to leptospirosis. But it didn’t tell us whether or not the disease was still present in the herd, nor if it was the primary cause of the abortions - because we didn’t have the aborted foetuses to test. “Leptospirosis not only has costly implications for the herd due to abortions and production losses, but it is also a zoonotic disease. So it’s paramount we vets work with farmers to protect their staff if there is a risk of infection.” “So that autumn we placed all the cows and heifers on a vaccination programme to control the disease. They would then need annual boosters. These are given in the spring at the same time as TB testing.” BVD control Due to the naivety of the herd to BVD, and the risk the disease poses to animal health and productivity, Sam also recommended that a BVD vaccination programme be adopted. Sam explains: “The test results indicated, with a fair level of confidence, that there were no PI animals in the herd, and hence there was no active virus. “However there is always a risk that the BVD virus can enter a farm. If cattle are not protected, it can circulate through the herd with significant negative consequences. “In fact, I’ve had clients in the past with herds which were naïve to BVD who decided not to vaccinate. But then the virus did enter the herd, for example, through bought-in animals, and consequently caused devastating results. “So I suggested that Richard introduce BVD vaccination into his herd health plan. After all, prevention is better than looking for a cure.” Accredited health status Richard now vaccinates all breeding stock for both BVD and leptospirosis, and has since joined a herd health scheme. Sam explains: “Because Richard and his team had put a lot of time and money into getting the herd onto a robust vaccination programme, I suggested he look into getting accredited for this work. “More and more buyers are looking at health status and it is something to be proud of. Being a member of a health scheme helps farmers to get a premium price for their cattle, especially for pedigree animals. “The requirements of Richard’s scheme are that a representative group of animals in the herd are screened annually for BVD, IBR, leptospirosis and Johne’s disease. Once three consecutive annual tests come back negative for a particular disease, the herd is given an accredited ‘low-level’ disease status,” explains Sam. “However, if test results come back positive, then we need to work together to determine the root cause of infection, and what action needs to be taken to prevent further animals becoming infected.” Sam adds: “Last year we screened Richard’s herd for IBR and found that 8 out of 127 cattle tested positive. As some had been bought-in, the decision was made to cull those eight that were positive, and then test the herd again at the same time as its annual TB test. If IBR is still present, then we may need vaccination in the future.” Disease control on-farm Richard explains. “I’m using vaccination as a preventative measure to mitigate the risk of BVD and leptospirosis infecting my cattle. It’s been easily incorporated into the herd health plan. “If we hadn’t PD-tested and looked into why those cows weren’t in calf, then who knows how many cattle may have become infected with leptospirosis, and the cost implications that could have entailed. “Although it was an initial cost to the business to put all the breeding cattle onto vaccination programmes, in the long-term, financial benefits will be seen through reduced incidence of abortion and limited production losses.” Sam adds: “The vaccination programmes are one part of maintaining a disease-free status, along with striving for a closed herd and implementing robust biosecurity protocols across the farm.” The herd tested naïve to BVD Richard Spencer is now vaccinating for leptospirosis and BVD