Use the same method to calculate the potential amount of manure produced in m3 from housed livestock using Table 4 and the reference data from Table 2.
A ‘straw addition factor’ (1.3 for dairy cattle or 1.15 for all other types of livestock) has been included along with a correction factor (0.70) to allow for the density of manures.
- Write the livestock type and number of housed livestock that produce the manure into the first two columns in Table 4
- Multiply this by the typical quantity (volume) of manure produced by that type of animal per week (using values from Table 2).
- Then multiply by the number of weeks each type of livestock is housed and multiply by the straw addition factor. Divide then by the manure density value which is 0.70.
This will give the manure produced over the housed period in m3.
An example is included in the first line of Table 4 based on 26 weeks (6 months) housing period using beef suckler cows over 500 kg, which will be multiplied by a straw addition factor of 1.15.
Table 4. Volume of manure produced over the housed period.
| 1 |
2 |
3 |
4 |
5 |
6 |
7 |
| Type of livestock |
Number of housed livestock |
Volume (m3) of manure produced per week (from Table 2) |
Number of weeks housed |
Straw addition factor
(1.3 for dairy; 1.15 all other livestock) |
Manure density value (divide by 0.70) |
Volume of manure produced over the housed period (m3) |
| Beef suckler cow (over 500kg) |
50 |
x 0.32 |
x 26 |
x 1.15 |
/ 0.70 |
= 683.43 |
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x |
x |
x |
/ |
= |
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x |
x |
x |
/ |
= |
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|
x |
x |
x |
/ |
= |
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|
x |
x |
x |
/ |
= |
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x |
x |
x |
/ |
= |
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x |
x |
x |
/ |
= |
| Total volume of manure (m3) |
= |
The total volume of manure in Table 4 gives an approximation of the amount of manure produced over the housed period and added to your store.
For example:
Manure production from 50 housed beef suckler cows (over 500 kg) during October (4 weeks) would be:
- Average weekly production from each cow (0.32 m3taken from Table 2), multiplied by the number of cows in the herd (50) = 16 m3 weekly.
- Before the straw addition factor and manure addition factors are applied, the monthly production is the daily production from the herd (16 m3), multiplied by the number of weeks in October (4 weeks) = 64 m3 in October.
- The October production (64 m3) is then multiplied by the straw addition factor of 1.15 which is for all other livestock (non-dairy) = 73.6 m3.
- The total manure volume produced over October with the straw addition factor considered (73.6 m3) is then divided by the manure density factor (0.70) = 105.14 m3.
You can use these methods to calculate how much slurry and/or manure from your housed livestock is added to storage systems on a month by month basis or across the full housed period.
This information is updated and abridged from The 4 Point Plan (2003).
