Where accurate or reliable weights are not available the age at start data entry must be used. This will assign stock in the mob being entered to national average weights and weight gain rates based on their age, class and breed.
The information required by the model is very clear in terms of how "dates" should be interpreted.
This definition may be different from those used elsewhere in the industry.
If you have older animals (e.g. older than 60 months sheep, you may wish to use "Breeding Ewes (Mixed Age) when no age is asked for, but the average weight can be defined).
Age at start is usually calculated from the date entered in Mean Lambing, Calving, and Fawning
The age entered is the age at their next monthly birthday i.e. 0–30 days old = 1 month, 30–60 days old = 2 months etc. i.e.
| Index | Age Range (months) | Age |
| 0 | 0 (Birth Weight) | |
| 1 | >0-1 | 1 |
| 2 | >1-2 | 2 |
| 3 | >2-3 | 3 |
| 4 | >3-4 | 4 |
| 5 | >4-5 | 5 |
Age = (months) that is entered into OverseerFM.
To make this simple, the table below can be used:
Select the month the animals are born from the row across the top
Select the current month from the columns below – also using the animals R1, R2, or R3 year