Welfare of meat chickens and meat breeding chickens: guidance
Detailed information about the needs of meat chickens and meat breeding chickens and how to meet these needs in accordance with good practice.
Annex 4: Cumulative Daily Mortality Rate (CDMR): worked example
The total mortality in the example below – a shed with 20,200 birds placed, one thinning and 549 birds dead in total – is 549/20,200 x 100 = 2.72%. The CDMR is 2.85%. In this example there is not much difference between the two figures, but this could have been greater if, for example, there had been high mortality in the house.
An Excel spreadsheet that keepers can use to calculate CDMR can be found at: https://www.gov.scot/publications/welfare-meat-chickens-mortality-rate-calculator/
(Please note that Excel does not round the numbers before calculating, which accounts for some apparent anomalies in the table below.)
| Age of birds/Day |
Number of birds in the house at the start of each day |
Number of birds culled AND number of birds found dead each day |
Daily mortality rate |
Cumulative Daily Mortality Rate (CDMR) |
|
|---|---|---|---|---|---|
| 1 |
20200 |
29 |
0.1436 |
0.1436 |
|
| 2 |
20171 |
20 |
0.0992 |
0.2427 |
|
| 3 |
20151 |
15 |
0.0744 |
0.3172 |
|
| 4 |
20136 |
15 |
0.0745 |
0.3916 |
|
| 5 |
20121 |
19 |
0.0944 |
0.4861 |
|
| 6 |
20102 |
10 |
0.0497 |
0.5358 |
|
| 7 |
20092 |
15 |
0.0747 |
0.6105 |
|
| 8 |
20077 |
20 |
0.0996 |
0.7101 |
|
| 9 |
20057 |
10 |
0.0499 |
0.7600 |
|
| 10 |
20047 |
12 |
0.0599 |
0.8198 |
|
| 11 |
20035 |
10 |
0.0499 |
0.8697 |
|
| 12 |
20025 |
8 |
0.0400 |
0.9097 |
|
| 13 |
20017 |
10 |
0.0500 |
0.9596 |
|
| 14 |
20007 |
9 |
0.0450 |
1.0046 |
|
| 15 |
19998 |
20 |
0.1000 |
1.1046 |
|
| 16 |
19978 |
15 |
0.0751 |
1.1797 |
|
| 17 |
19963 |
9 |
0.0451 |
1.2248 |
|
| 18 |
19954 |
8 |
0.0401 |
1.2649 |
|
| 19 |
19946 |
10 |
0.0501 |
1.3150 |
|
| 20 |
19936 |
19 |
0.0953 |
1.4103 |
|
| 21 |
19917 |
10 |
0.0502 |
1.4605 |
|
| 22 |
19907 |
8 |
0.0402 |
1.5007 |
|
| 23 |
19899 |
10 |
0.0503 |
1.5510 |
|
| 24 |
19889 |
9 |
0.0453 |
1.5962 |
|
| 25 |
19880 |
21 |
0.1056 |
1.7019 |
|
| 26 |
19859 |
14 |
0.0705 |
1.7724 |
|
| 27 |
19845 |
27 |
0.1361 |
1.9084 |
|
| 28 |
19818 |
12 |
0.0606 |
1.9690 |
|
| 29 |
19806 |
6 |
0.0303 |
1.9993 |
|
| 30 |
19800 |
22 |
0.1111 |
2.1104 |
|
| 31 |
19778 |
31 |
0.1567 |
2.2671 |
|
| 32 |
16548 |
19 |
0.1148 |
2.3819 |
Thinned |
| 33 |
16529 |
21 |
0.1270 |
2.5090 |
|
| 34 |
16508 |
12 |
0.0727 |
2.5817 |
|
| 35 |
16496 |
10 |
0.0606 |
2.6423 |
|
| 36 |
16486 |
8 |
0.0485 |
2.6908 |
|
| 37 |
16478 |
26 |
0.1578 |
2.8486 |
Cleared |
Contact
Email: Kirsten.Foubister@gov.scot
There is a problem
Thanks for your feedback