| Toggenburg Cluster Analysis |
|
Data was obtained from the ADGA for 8 dairy breeds. All results were limited to those animals reported as Purebred (PB) or American (AM); however, all animals were included in the pedigree analysis to establish ties between animals, including cases where the ancestors are from another breed. Cluster analysis is a procedure that groups related animals based on pedigree relationship. This is a technique used by NAGP to assess where repository animals are grouping with the currently available genetic pool for each breed. It also establishes a practical approach for obtaining animals for the repository in a way that maximizes genetic diversity. Animals that were included in the cluster analysis included sires of PB and AM offspring born 2010 to present that are also PB or AM themselves. Repository bucks are also included in the clusters.
Table 1 shows the summary statistics based on the pedigree and cluster analyses.
Pedigree & Inbreeding Analysis
Inbreeding levels have steadily increased over time. Animals born in 2013 have an average inbreeding level of 12%, approximately the relationship of cousins.
Number of registrations peaked for birth year 1983 at 4,648; registrations for birth year 2013 were 1,471.
Figure 2. Toggenburg goats registered by birth year
Almost all Toggenburgs born in the past 20 years have some level of inbreeding, as shown in Figure 3.
Figure 3. Percent of Toggenburgs with an inbreeding coefficient greater than zero by birth year
Fifty-four percent of the current (born 2009 and later) Toggenburg population has an inbreeding coefficient of less than 0.10.
Figure 4. Percent of Toggenburgs born 2009 and later by inbreeding category
Sixteen clusters were selected to represent the populations within the Toggenburg breed (Figure 5).
Figure 5. Tree diagram for Toggenburg cluster analysis of sires of PB and AM offspring born 2010 and later that are PB or AM themselves (gold line depicts cluster level)
The 1,252 clustered bucks had an average relationship of 14.1%. There are only two Toggenburg bucks in the repository, and they are represented in Clusters 5 and 8. Table 2 shows the cluster summary.
Although the within cluster relationships (diagonal) are generally higher than the between cluster relationships (off-diagonal), there are many high relationships between clusters (Figure 6).
Figure 6. Within and between cluster relationship matrix for Toggenburg
The Toggenburg repository bucks did not have current PTA available; nonetheless, PTA for the breed average for Milk, Fat, and Protein are shown in Figures 7, 8, and 9, respectively.
Figure 7. Toggenburg genetic trend for Milk PTA
Figure 8. Toggenburg genetic trend for Fat PTA
Figure 9. Toggenburg genetic trend for Protein PTA
return to top
