Download presentation
Presentation is loading. Please wait.
Published bySolomon Sharp Modified over 9 years ago
1
Anette van Dorland ILRI, Addis Ababa, Ethiopia, 26 February 2003 Clustering of breed types: Preliminary results
2
Introduction 1.Large number of unknown breed types: How different/similar are these breed types from each other ? 2.Farmers knowledge versus enumerator observation Multivariate techniques
3
Introduction (cont.) Approach I: Grouping of entities based on the multivariate similarities among the entities No prior information of the formed groups available Cluster analysis Approach II: Grouping of entities based on the multivariate similarities among the entities Prior information of the formed groups available Discriminant analysis
4
Data on cattle from Borana Zone Five woreda’s selected (see map) Borana Zone Bore Hagere Mariam Liben Dire Teltele Three woreda’s predominantly in lowland (Dire, Liben and Teltele) Two woreda’s predominantly in highland (Bore and Hagere Mariam) Borana Zone Oromia Region
5
209 records on breed types 26 qualitative variables on phenotypic characteristics First step: Principal Components Analysis Second step: Agglomerative Hierarchical Clustering (AHC) Mahalanobis’ distance (dissimilarity) Strong linkage as aggregation criteria Data and Methodology
6
Principal Components Analysis Characteristic Coat colour-body Coat pattern Hair size Hair type Frame size Dewlap size Hump size Hump shape Face profile Back profile Rump profile Ear size Ear shape Ear orientation Horn length Horn shape Horn orientation Horn spacing Tail length Udder size Teat size Navel flap size Coat colour-head Coat colour-ears Coat colour-hoof Coat colour-tail 10 principal components responsible for 64 % of the variation between the observations
7
Principal Components Analysis (cont.) Contributions of the variables (%)
8
Agglomerative Hierarchical Clustering: Dendrogram
9
Dendrogram (cont.) Dissimilarity Cluster 1 Cluster 2 Cluster 3 (11 observations) (70 observations) (128 observations)
10
Distribution of animals of cluster 1
11
Distribution of animals of cluster 2
12
Distribution of animals of cluster 3
13
Coat colour of body: cluster 1 0 5 10 15 20 25 30 35 40 123456 Coat colour combination of body % of households
14
Coat colour of body: cluster 2 0 5 10 15 20 25 123456 Coat colour combination of body % of households
15
Coat colour of body: cluster 3 0 5 10 15 20 25 123456 Coat colour combination of body % of households
16
Physical characteristics
17
Physical characteristics (cont.)
18
Distribution of clusters by agro-ecological zone
19
Distribution of clusters by production system
20
Quality of traits: Production traits
21
Quality of traits: Adaptation traits
22
Suggestion Dissimilarity Cluster 1 Cluster 2 Cluster 3 ‘Borana’ group ‘Guji’ group ?
23
Distribution of breed types (farmers’ knowledge) Borana Zone Breed type Guji Arsi Borana Konso Ogaden ArsixBorana BoranaxGuji BoranaxKonso Unknown
24
Further analysis…..
25
Conclusions Multivariate techniques can be used for on-farm breed characterization work by classifying the observations on individual animals into well-defined breed types/strains Multivariate techniques can help formulating hypotheses, which can be tested using detailed genetic studies Multivariate techniques can facilitate more focused genetic studies including molecular biology
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.