Bad calving impacts on both cow fertility and milk production
Take Home Message: Avoid difficult calvings as these are linked to declining fertility and decreased milk yield in early lactation
There is a detrimental effect of a bad calving on cows’ subsequent fertility and milk production. When calving difficulty increases, fertility declines and milk yield in the first stage of lactation also decreases.
Some of the key findings of a recent trial, carried out by scientists in Scotland, which were presented to delegates at this year’s British Society of Animal Science’s annual conference, held at Queen’s University, Belfast.
Being one of the most economically significant non-production traits, calving ease has a large impact on the dairy industry. “And, in addition, calving difficulty is ranked an extremely painful condition of cattle, which suggests that the impact of this trait also greatly affects animal welfare,” said the Scottish Agricultural College’s Sophie Eaglen.
“It is therefore plausible that there will be a detrimental effect of a difficult calving on the subsequent performance of the animals involved. So the objective of our study was to use UK Holstein-Friesian cattle data to phenotypically analyse the effect of calving ease on fertility and milk production, of both cow and calf, in their subsequent lactation,” she added, explaining the rationale behind her team’s work.
Using first parity calving ease records only, provided by the Cattle Information Service (CIS) and National Milk Records (NMR), the team merged the calving ease and fertility data to produce a total of 32,483 and 8,184 records of cow and calf, respectively, originating from 2,486 and 1,410 herds.
Fertility data consisted of the calving interval (CI), number of inseminations (NINS), non-return at 56 days (NR) and days to first service (DFS), of the first lactation following the recorded calving.
Merged calving ease data and production data led to a total of 348,648 and 81,885 records of cow and calf, originating from 2,148 and 1,153 herds, respectively.
“And we found that there was a significant difference in the fertility of cows for different categories of calving ease. Between an easy calving (1) and vet assisted calving (4), there was an increase of 28 days in CI, 0.7 services in NINS, and seven days in DFS,” said Miss Eaglen.
NR showed a decrease of 9% between an easy and vet assisted calving, though this was not significant.
The effect of calving ease on the cumulative milk yield of the first three test days showed a significant difference between all calving ease categories in the cow analysis. Between an easy and vet assisted calving, milk yield decreased by, on average, 1.67kg per test day or 6.1%.
“A significant effect of calving ease on the subsequent production and fertility of the calves was not found. Though, calves which were delivered with veterinary
assistance showed a tendency to decrease in milk yield in the first stage of their lactation as heifers, in comparison to calves delivered with moderate farmer assistance,” said Miss Eaglen, adding that further study is needed to analyse the effect of calving ease on the full subsequent lactation.
Presented to the British Society of Animal Science Annual Conference, 12-14 April , 2010, Queen’s University, Belfast.
Eaglen SAE, Woolliams JA, Coffey MP and Wall E: “Effect of calving ease on the subsequent performance of cow and calf in UK Holstein Friesian cattle.”
To view proceedings of all summaries presented at the Annual Conference 2010 http://www.bsas.org.uk/Publications/Annual_Conference_Proceedings/ To view all Powerpoint presentations http://www.bsas.org.uk/Members_Area/
For further information contact: BSAS on 0131 445 4508 or bsas@sac.ac.uk
