Gilt replacement simulator

Goal

Simulator designed to calculate the entry of gilts when starting a farm, when increasing its sow census or in order to calculate the replacement rate of an operating farm.

 

Instructions

The user must fill in the cells corresponding to the number of sows, the maximum number of farrowings, the farrowings per sow per year, etc. with the desired values.

Initially, a series of values are presented as an example. In case that a user does not enter a new datum in the box, the simulator will use the already existing value.

 

Some considerations with respect to the simulator:

1. It is recommended to enter values that are realistic and near to the real goals so the results are useful.

2. The gilt culling percentage from the moment of their entry in the farm until their mating should fall between a 5% and a 20%, being higher when the start of the farm arises under complicated situations (hot periods or with an insufficiently trained staff, etc.).

3. During the first three years the simulator considers that the replacement rate will not be the same than that of an already operating farm because the sow population will still be very young. From the 4th year onwards the replacement rate will be calculated in the "operating farm" section.

4. The total of gilts to be entered in the farm for its filling up is shared out in the first 4 months with the biggest part of the nulliparous sows during the first month.

5. The "goal census" graph shows the profile of an ideal census according to the maximum parturition at which the sows will be culled and to the loss of sows between each parity.

6. The results show the number of gilts that have to be entered in the farm every week and every month.

7. The results also show the number of matings of gilts that must be carried out in order to attain the farrowings goal according to the expected fertility of the farm.

8. In the "farm enlargement" section, the nulliparous sows needs in order to carry out the expanding of  the farm and the nulliparous sows necessities in order to maintain the replacement goal based on the previous census of the farm are shown separately.