1. Genetic diversity of sires used in the Irish dairy industry
Maintenance of genetic diversity in the Irish dairy industry is one of the driving motivations for having a nationally co-ordinated progeny test structure. This paper reports on analysis of co-ancestry and inbreeding trends between and among cohorts of bulls with progeny in Ireland over the past 15 years. The cohorts include bulls used widely and not included in the progeny test, bulls sourced from Ireland included in the progeny test, foreign sourced bulls included in the progeny test, and those foreign bulls not included in the progeny test. Average co-ancestry for these bulls with subsets of the cow population are also presented. The cow population is divided into those herds who have had a contract mating organised with an artificial insemination breeding company at least once in their history, versus those that have not.
Fiona Hely, Francis Kearney, Andrew Cromie, Daragh Matthews and Peter Amer

2. Background Gene Ireland progeny test program launched in 2005
Objective to identify superior young bull candidates
Panels of around 70 bulls are evaluated every year
Each bull to have 100 heifer replacements recorded in 100 herds by year 4
Genomic evaluations first launched in 2009

3. Introduction to analysis
Does the Gene Ireland progeny test program help maintain diversity
Understand relationships between and within bull types

4. Data analysed Pedigree for Holstein Friesian milking animals
Extracted pedigree of around 6.1M animals
Focus on cows from 1997 onwards
CFC software by Sargolzaei et al.

5. Dairy bull categories Male calf registration list Contract matings
Progeny test panel
Active AI List
Elite bulls
What are the Objectives of the G€N€ IR€LAND® Dairy Programme?
The objective of the Gene Ireland Dairy programme is to test bulls each year and that each bull would have 100 heifer replacements recorded in 100 herds, by year 4 of the programme.
Gene Ireland Dairy is focused on three key areas:
The selection of high EBI young bulls.
2. Progeny testing the young bulls on a “Targeted” set of herds.
3. Elite bulls are returned to AI.
Imported foreign bulls

6. Dairy bull categories Imported foreign bulls Other Irish born bulls
Male calf registration list
Contract matings
Progeny test panel
Active AI List
Elite bulls
What are the Objectives of the G€N€ IR€LAND® Dairy Programme?
The objective of the Gene Ireland Dairy programme is to test bulls each year and that each bull would have 100 heifer replacements recorded in 100 herds, by year 4 of the programme.
Gene Ireland Dairy is focused on three key areas:
The selection of high EBI young bulls.
2. Progeny testing the young bulls on a “Targeted” set of herds.
3. Elite bulls are returned to AI.
Imported foreign bulls

7. Dairy bull categories
Group
Irish Born
Foreign Born
Progeny Test
PT IRL
PT FOR
Other
O IRL
O FOR
Focus on bulls contributing to the top 80% of inseminations
88 bulls for progeny test inseminations (~3M)
151 bulls for other bull inseminations (~1.8M)

8. Progeny by bull type

9. Progeny by bull type
PT launch

10. Progeny by bull type
2005 PT bulls used
at 4 years old
PT launch

11. Progeny by bull type 2005 PT bulls used at 4 years old Genomic proofs
PT launch

12. Progeny by bull type

13. Relationship within category

14. Relationship between groups
Other Irish bulls were least related to all other widely used bull types
Other Foreign bulls had a higher relationship between groups
Average relationship
PT IRL
PT FOR
O IRL
O FOR
0.069
0.051
0.082
0.035
0.026
0.12
0.06
0.065
0.038
0.089

15. Relationship between groups
Other Irish bulls were least related to all other widely used bull types
Other Foreign bulls had a higher relationship between groups
Average relationship
PT IRL
PT FOR
O IRL
O FOR
0.069
0.051
0.082
0.035
0.026
0.12
0.06
0.065
0.038
0.089

16. Relationship between groups
Other Irish bulls were least related to all other widely used bull types
Other Foreign bulls had a higher relationship between groups
Average relationship
PT IRL
PT FOR
O IRL
O FOR
0.069
0.051
0.082
0.035
0.026
0.12
0.06
0.065
0.038
0.089

17. Relationships with cow cohorts
O FOR

18. Relationships with cow cohorts
O FOR
PT IRL

19. Relationships with cow cohorts
O FOR
PT FOR
PT IRL

20. Relationships with cow cohorts
O FOR
PT FOR
PT IRL
O IRL

21. Relationships with cow cohorts
O FOR
PT FOR
PT IRL
O IRL
Average relationship
PT IRL
PT FOR
O IRL
O FOR
0.069
0.051
0.035
0.06
0.082
0.026
0.065
0.12
0.038
0.089

22. Relationships with cow cohorts
O FOR
PT FOR
PT IRL
O IRL

23. Relationships with cow cohorts
O FOR
PT FOR
PT IRL
O IRL

24. Average inbreeding by category

25. Average progeny inbreeding
O FOR

26. Average progeny inbreeding
O FOR
PT IRL

27. Average progeny inbreeding
O FOR
PT IRL
O IRL

28. Average progeny inbreeding
O FOR
PT IRL
O IRL
PT FOR

29. Average progeny inbreeding
O FOR
PT IRL
O IRL
PT FOR

30. Take home messages
Does the Gene Ireland progeny test program help maintain diversity?
Lowest relationship within group
Average relationship with cows reasonably steady
Control of sire flows
Potential to use genomic inbreeding measures to manage coancestry in progeny test candidates in the future

31. Thank you