BVD vaccination can lift milk yields, trial shows

Vaccinating dairy cows against the bovine viral diarrhoea (BVD) virus can lift milk yields by up to 1 litre/day, a recent global study has shown.

A total of 1,463 cows across four herds endemically infected with BVD were vaccinated with Bovela. Half of the animals in each herd were left unvaccinated to compare the effects vaccination had on reproduction and milk yields.

Presenting the findings at the UK-Vet Health Herd digital conference last week (21 October), lead researcher Ellen Schmitt said no differences were found in the frequency of embryonic losses between vaccinated and non-vaccinated animals.

See also: BVD project extended after Covid-19 delays

However, milk yields on three of the four farms that took part in the trial increased in early and mid-lactation (see “The effects vaccination has on milk production” below).

Dr Schmitt said the farmers who took part in the trial were sceptical about the economic justification for vaccination. However, she said the trial proved that BVD has a negative effect on milk production, even in endemically infected herds, where you would expect there to be minimal number of animals at risk.

In the trial, fresh cows, dry cows, lactating cows and breeding heifers were vaccinated at the same time and no adverse effects were found.

Dr Schmitt added: “Bovela can be used to vaccinate the entire herd on the same day, regardless of the gestation or lactation.”

The effects vaccination has on milk production


Milk production

Farm 1 (UK)

+1.023 litres/day during early lactation

Farm 2 (UK)

+1.799 litres/day during mid-lactation

Farm 3 (Italy)

+0.611 litres/day during early lactation

Farm 4 (France)

No difference in milk production

*Early lactation (8-102 days in milk); mid 103-204 days in milk; and late 205-305 days in milk. The farm that showed no difference in milk yield was running milking robots.

Return on investment

Increase in milk yield (litres) in early lactation a head a day (*DIM 8-102 = 94 days)


Total increase in milk yield a cow across early lactation – 169.2 litres

Animals in milk


Total increase in milk yield in early lactation across the herd – 33,840 litres

Milk price (p/litre)


Total increase in income across the herd – £8,798.40

Average cost of vaccine a head (300) including vaccine, labour and equipment 


Total vaccine cost across the herd – £1,800

Return on investment

£6,998.40 (increase in income minus vaccine cost across the herd)