Case Awards 2016

Watergate Farm, near Harrogate is a great example of a farm that has worked hard to eradicate BVD from their herd and are now seeing and feeling the benefits of being BVD free. The Baul family are milking a closed herd of just short of 200 pedigree Holsteins calving all year round and averaging just over 9,000 litres milk sold/cow/year. Over the last year calving interval has been as low as 402 days all cows are served by AI to mainly black and white sexed semen.

The case starts with a call from a dairy farmer requesting a reproductive control service, specified on the day of the visit. We arrived at a farm with 80 adult cows, animals that
had given birth at least once, 16 heifers under one year old and 22 heifers over one year but under 32 months. The farmer hired us to perform a reproductive control on the herd. We started by taking data, case history... It seemed that the number of young animals was small for the number of adult cows.

This case report will discuss the pitfalls of BVDV control management on a Dutch dairy farm where BVDV re-entered the farm after several years of being “BVDV free” and vaccination.

We observed 50% of PI births in the case of the Rubia Gallega breed, whereas this percentage was 20% in the Holstein herd. Is it possible that BREED influences the likelihood of breeding a PI fetus?”

“I have a lot of doubts about what happened on this farm: a BVD clinical picture that I have never seen in my vast professional experience with BVD, in which PI
outbreak occurs usually in a short period of time and just few PI animals are detected.”

A beef herd which had previously been considered free of BVD was found to have a positive young stock check test in 2012.

Following the detection of circulating BVD virus, the farmer vaccinated the animals but did not detect and cull PI animals until much later. His losses were estimated at €28K.

Farmers must be encouraged to start and finish a committed BVD eradication program to prevent high economic losses associated with the disease. Vets should be encouraged to carry out risk management analyses and engage in business analyses to demonstrate and discuss the benefits and the costs involved in disease interventions in each specific farm, including vaccination programs.

Between August 2015 and beginning January 2016 a 240 Holstein cow dairy herd had seen treatment and mortality rates increased in the group housed pre-weaned calves. Bovine respiratory disease (BRD) and neonatal diarrhea treatment rates were estimated to have increased from 5% to 50% and from 10% to 20% respectively. From farm records pre weaning mortally from May to July 2015 was 3% and 8% in November to December 2015. No increase in abortions or stillbirths was reported.

ELISA tests detected BVD virus in a herd of Holsteins and Charolais cattle. The presence of a PI animal was confirmed in a four-year-old primipara.

This case shows the importance of BVD as an underlying disease which must be eradicated from a farm to ensure that all other disease control protocols also have a successful outcome.

Dairy farm with 105 milking cows in Lugo, Galicia, Spain. It was a BVD-negative farm, aware of biosecurity, applying BVD-Ag-analysis to all bought animals. Good managed farm, with genetically high value cows, producing and selling embryos.

The suspected source of introducing the outbreak was through colostrum of an afterwards BVD-positive confirmed cow from another herd. But this was not confirmed.

In this case we found CNS symptoms in twin Holstein calves exhibiting congenital cataracts. The tests performed did not reveal the aetiology of the pathological findings but were strongly indicative of a prior BVD infection of the mother cow. After other causes were ruled out, “congenital cataracts caused by BVDV” is regarded as a strong possibility.

A block calving dairy herd from south Co. Carlow, Ireland referred two calves to the University Veterinary Hospital with neurological signs and a history of smaller than normal calves.

“A battery of tests performed during an outbreak of neonatal diarrhea with high mortality did not detect BVD virus. Yet two PI animals were identified three months later. Identification of PI animals and vaccination led to a reduction in diarrhea cases and shorter calving intervals.”

“Given the farm’s recent history, I suspected it could be a new case of mucosal disease in a PI animal, which is why we tested all animals older than 3 months on the farm for BVD antibodies, and those that were negative we then tested for BVD antigen.”