DEFRA advises on chicken mortality rates

DEFRA is urging broiler producers to revisit the way they calculate and report mortality rates, to ensure they are compliant with the Broiler Welfare Directive, which came into effect in 2010.

Under the directive there is a legal requirement for producers with more than 33kg of live birds per sq m to record daily mortality rates and cumulative daily mortality rate. This CDMR must be submitted with any Food Chain Information forms sent to the slaughterhouse, including when flocks are thinned.

“You may need to change the system that you are using to record and monitor mortality,” said a statement. “In your old system, you will be familiar with recording total birds dead (including culls) every day, then adding this up to the end of the flock.

“You then calculated percentage mortality from the total birds dead throughout the rearing period divided by the original number of birds placed at day zero.

“But the new system calculates the percentage mortality by working out the proportion of dead birds in a day, based on the number of birds remaining in the house.

“The effect of this is that, if a large number of birds die at the start of a crop, this will be a smaller percentage mortality under CDMR than if the same number of birds died in the final week.

“This is logical because, when large numbers of chicks die in the first week, this may often be associated with parent flock/hatchery issues, rather than problems on the farm.”