Simple monitoring network

Monitoring 12 sows (DRGTTST5.NET)

If the BN in figure 2 of 12 sows are combined, the probability distribution of the number of farrowings can be found, i.e. corresponding to a batch farrowing system with 12 matings per week.

This is obtained by introducing Pregnancy, Heat_diagnosis and Pregnancy_diagnosis nodes for each sow. These three nodes have the same parents as the corresponding nodes in the example in section 3. The corresponding net is shown in figure . In the figure this part of the network comprises the pregnancy part. In addition sum nodes are defined. These nodes add the number of pregnant animals. First by combining the pregnancy nodes pairwise, then by adding these sum nodes pairwise, etc. As an example the sum nodes sum_14 and sum_58 each have the states {0,1, ..., 4}. They are parents of the node sum_18 that has state levels {0, 1, ..., 8}. This technique improves the efficiency of the calculation.

Figure 3: 12 sow pregnancy test network

Note that the herd level of pregnancy rate, quality of the heat detection and quality of pregnancy testing are parents to all the individual sow nodes. Each outcome of a pregnancy diagnose is thus combined to give information concerning these nodes. As more pregnancy tests are performed, our knowledge of these nodes becomes more precise.