Summer has certainly been better than last year with the problem being the quantity of grass conserved rather than quality. The welcome rain has made everywhere look a bit greener—it was starting to look a bit like the Mediterranean in some places. The culture results from the TB suspect mentioned in the last newsletter have come back clear so the farmer has had his movement restrictions lifted and will not need to test again for 4 years.
BVD infection continues to be a concern in the national herd, with some figures suggesting that as many as 60% of herds may have active infection in the herd in the form of a PI (persistently infected) animal. This animal will be shedding virus to all other animals it meets and causes them to have reproductive problems and immunosuppression. Reproductive problems will show as failure to get in calf, irregular returns to heat and abortion, whereas immunosuppression will cause problems like scour and pneumonia in your youngstock. In some cases, the BVD infection causes death on its own, but when you add in the secondary scour and pneumonia then the death rate can increase.
Control is difficult because infecting a cow for the first time in early pregnancy can result in the birth of a PI (persistently infected) animal. This animal can appear perfectly healthy but be a continual source of infection in the herd. They can survive into adulthood so removing these animals will be necessary to prevent further spread of infection and so more losses. You may be aware that Scotland has introduced a policy to remove all BVD positive animals from the country and all cattle entering Scotland need to be tested and certified as BVD free. DEFRA has now introduced a BVD “Stamp It Out“ campaign with the aim being to remove all infected animals from England. There is an opportunity to get funding to determine if BVD is present in your herd and so find and remove the infected cattle. If you are interested in finding out more then please let us know.
Sheep abortion vaccines are available and can to be given from 4 months to 4 weeks before tupping. Enzovax for enzootic abortion is currently only available in 10 and 20 dose packs, and we are able to get it delivered the following working day. Toxovax helps protect against toxoplasmosis which is spread by cats and has to be ordered direct from the manufacturer. It comes in 20-dose and 50-dose packs with orders being delivered only on Wednesdays. They must be placed at least 1 week before you want them, but we can request a delivery date in September if you want. The vaccine will come with a short shelf life which means it usually needs to be used with 7-10 days of delivery. Nationally there has been an increase in the number of flocks using Toxovax, with the peak months for vaccination being September and October. MSD Animal Health, the makers of Toxovax are concerned they will reach maximum capacity for production in September and October and may not be able to supply 100% of product required. They are therefore keen for farmers to bring vaccination forward into August where possible and are offering a deal/promotion on Toxovax purchased and delivered in August.
We recently diagnosed a case of Redwater fever in an area previously not known to have the disease. Redwater is caused by a parasite carried by ticks. Affected cattle initially show reduced appetite and scour which progresses to severe anaemia and red coloured urine. Although an uncommon disease, this case shows that it is spreading to new areas. Cattle most at risk tend to be bought in animals from ‘clean’ areas, turned out onto tick-infested pasture. Homebred cattle infected as calves are not affected.