Louise Hartley speaks to Dr Kat Hart, George Farm Vets, Wiltshire, for advice on preventing and recording stillbirths on-farm.
Stillbirths are classified as a calf which dies at any point between day 272 of gestation, being born dead, and 24 hours after its birth.
Dr Hart says: “The stillbirth rate of the UK dairy herd is about 8 per cent and 3.5 per cent for the beef herd. This seems a high level, however the rate in Sweden is 10.3 per cent and Canada’s dairy stillbirth rate is about 10-12 per cent.”
Stillbirths represent a large loss in income. Figures based on DairyCo data from all calves sold at market in August 2015, suggest bulls cost £64 at 42 days of age. The cost of beef cross calves is considerably higher, with Hereford cross heifers reaching £203 and bulls at £257. Continental crosses are higher again, at £252 forheifers and £300 for bulls.
So few dairy heifers are sold at such a young age, it is difficult to give an exact figure, but DairyCo-funded research suggests the cost of a heifer mortality is £140 for every live heifer born, says Dr Hart.
“This means for an average 100-cow dairy herd with 8 per cent stillbirth rate and using traditional dairy semen, eight calves will be lost per year – if four are bulls and four are heifers, it will mean a loss of £816.
“If half the losses are beef calves, this would rocket the loss to £1,512 per year,” explains Dr Hart.
Stillbirth records are becoming increasingly important as more farm assurance schemes require this data to be collected and reviewed, says Dr Hart.
“The vet’s quarterly meeting is ideal for this, however recordkeeping using computer software is complex. Often simple spreadsheets or handwritten sheets work just as well.
“Recording extra data, such as whether the calving was assisted or if the cow calved on her own, is also good information. This can be recorded in the same place as stillbirths.”
There are many possible causes when a calf is born dead. These are mainly linked to a prolonged labour and pressure on the navel cord stopping oxygen transfer.
Eye colour can help determine the length of time a calf has been dead – if the eye has turned cloudy this indicates the calf has been dead for more than six hours.
Other causes include deficiencies of minerals, such as iodine and selenium, and infectious diseases, such as neospora, leptospirosis and BVD.
In beef herds, stillbirths are considered the second highest loss after poor fertility.
Dr Hart says: “If a cow does have a dead calf, there are two options. The cow can be left to come around the next year, but this often results in a fat cow and a significant loss of earning potential. Mastitis can sometimes occur in cows which have bagged up well and are leaking milk.
“The other option is to buy a calf and adopt it onto the cow. This can be labour intensive and is a large biosecurity risk. Make sure all bought-in calves come from a farm of similar herd health status and are not BVD persistently infected animals.
“Records are extremely important as the cow should be culled if it repeats the following year.”
Dr Hart says farmers are often shocked when told about their farm’s stillbirth rate.
She says: “The figure is simple to work out if dead calves are recorded in a diary.
“The total number of calvings over either a year or three-month period should be counted and compared to the number of calves born dead over the same period of time.
“The other, more crude option for milking cows is to count the number of tags used over a year and the number of cows which have returned milking, to calculate the born live rate.
“However, this does not take into consideration twins, for example. If replacement calves are bought-in, a crude figure of the stillbirth rate is the number of bought-in calves compared to the number of cows calved.
“If the result is higher than expected, many areas can be assessed and improved, often at minimal cost. Focusing on this small area can have a dramatic long-term impact of farm economics and staff morale.”