Sire selection can reduce calf mortality on first parity cows
Take-home message: Selecting sires based on survival expectancy is probably the most practical method to reduce newborn calf mortality from first parity cows, particularly on farms with relatively high calf losses.
The stillbirth of calves, particularly from first calving heifers, is something many dairy farmers would like to reduce due to its effects on economics, animal welfare, and public concerns about dairy farming.
Calving difficulties, prolonged deliveries, as well as body shape of the calves, are important factors affecting stillbirth.
Despite the low heritability, the likelihood that a calf would survive being born can be increased by using sires with favourable genetics.
A study published in the journal Animal shows that herds with low livability (high stillbirth rates), could benefit most from improvements in sire selection.
Scientists from the Netherlands investigated heifer calf livability considering factors such as herd differences, genotype and their environment interactions.
A large dataset with data from calvings between 1993 and 2012 of Dutch dairy farms was used.
There were considerable differences between herds in livability of calves from heifers, with averages ranging from 74% to 95%.
The researchers found that in herds where the likelihood of stillbirth was highest, the heritability and genetic variation of first born calf survival were also substantially larger.
Dr Wijbrand Ouweltjes from Wageningen University suggested that for herds with a relatively high stillbirth incidence, selecting sires with favourable breeding values is expected to be twice as effective and profitable as in herds with a relatively low stillbirth incidence.
There may be other management options such as monitoring and intervention, to reduce birthing related death, but such changes require continuous efforts of the farmer.
Therefore, sire selection for livability is probably the most practical method to reduce perinatal death, particularly on farms with relatively high calf losses.
Written by Joanne Stocks, University of Nottingham
Original paper: W. Ouweltjes, J. J. Windig , M. L. van Pelt and M. P. L. Calus, Animal (2015), 9:10, pp 1617–1623