# Presentation: 667524

## Selection Differentials from National Holstein Bull Progeny Test Programs Estimated from International Data

## Characteristics of Ideal Progeny Test Program

**High pedigree merit**
**Large number of bulls**
**Rapid and accurate evaluation**
**Large number of daughters/herds**
**Intensive culling**

## Objective

**Document characteristics of national progeny test (PT) programs**
**Age of bulls at decision**
**Percent of bulls retained**
**Standardized selection differentials**
**(selection intensities)**
**Compare PT strategies of different countries**

## Comparison Considerations

**Many factors affect PT program quality**
**Complex relations between factors**
**A country may have higher pedigree requirement, but return more bulls to service and have a *****lower***** selection differential.**

## Data

**Holstein Interbull evaluations**
**PT decisions February 1996 - 1998 **
**Eleven countries with at least 125 PT bulls over this period**

## Assumptions

**PT decision made on second evaluation**
**provided by Interbull**
**Country of PT was country with most daughters in decision evaluation**
**Returned to service if 200 daughters added in country of PT from evaluations 2.5 to 4.5 years after PT decision**

## Numbers of Bulls 

| Country | Evaluations | Bulls | Bull Age (mo) |
| --- | --- | --- | --- |
| Australia | 1 | 153 | 69 |
| Canada | 5 | 1108 | 69 |
| Denmark | 5 | 888 | 66 |
| France | 5 | 1547 | 77 |
| Germany | 5 | 1855 | 70 |
| Great Britain | 3 | 145 | 72 |
| Italy | 5 | 735 | 73 |
| Netherlands | 5 | 1055 | 66 |
| New Zealand | 2 | 266 | 67 |
| Sweden | 5 | 223 | 75 |
| United States | 5 | 3616 | 66 |

## Numbers of Bulls 

| Country | Evaluations | Bulls | Bull Age (mo) |
| --- | --- | --- | --- |
| Australia | 1 | 153 | 69 |
| Canada | 5 | 1108 | 69 |
| Denmark | 5 | 888 | 66 |
| France | 5 | 1547 | 77 |
| Germany | 5 | 1855 | 70 |
| Great Britain | 3 | 145 | 72 |
| Italy | 5 | 735 | 73 |
| Netherlands | 5 | 1055 | 66 |
| New Zealand | 2 | 266 | 67 |
| Sweden | 5 | 223 | 75 |
| United States | 5 | 3616 | 66 |

## Numbers of Bulls 

| Country | Evaluations | Bulls | Bull Age (mo) |
| --- | --- | --- | --- |
| Australia | 1 | 153 | 69 |
| Canada | 5 | 1108 | 69 |
| Denmark | 5 | 888 | 66 |
| France | 5 | 1547 | 77 |
| Germany | 5 | 1855 | 70 |
| Great Britain | 3 | 145 | 72 |
| Italy | 5 | 735 | 73 |
| Netherlands | 5 | 1055 | 66 |
| New Zealand | 2 | 266 | 67 |
| Sweden | 5 | 223 | 75 |
| United States | 5 | 3616 | 66 |

## Herds, Daughters, and Reliabilities

| Country | Herds | Daughters | REL (%) |
| --- | --- | --- | --- |
| Australia | 42 | 76 | 80 |
| Canada | 61 | 70 | 86 |
| Denmark | 79 | 91 | 88 |
| France | 75 | 79 | 87 |
| Germany | 75 | 104 | 89 |
| Great Britain | 38 | 58 | 84 |
| Italy | 54 | 70 | 84 |
| Netherlands | 114 | 125 | 92 |
| New Zealand | - | 103 | 89 |
| Sweden | - | 147 | 91 |
| United States | 39 | 54 | 80 |

## Herds, Daughters, and Reliabilities

| Country | Herds | Daughters | REL (%) |
| --- | --- | --- | --- |
| Australia | 42 | 76 | 80 |
| Canada | 61 | 70 | 86 |
| Denmark | 79 | 91 | 88 |
| France | 75 | 79 | 87 |
| Germany | 75 | 104 | 89 |
| Great Britain | 38 | 58 | 84 |
| Italy | 54 | 70 | 84 |
| Netherlands | 114 | 125 | 92 |
| New Zealand | - | 103 | 89 |
| Sweden | - | 147 | 91 |
| United States | 39 | 54 | 80 |

## Herds, Daughters, and Reliabilities

| Country | Herds | Daughters | REL (%) |
| --- | --- | --- | --- |
| Australia | 42 | 76 | 80 |
| Canada | 61 | 70 | 86 |
| Denmark | 79 | 91 | 88 |
| France | 75 | 79 | 87 |
| Germany | 75 | 104 | 89 |
| Great Britain | 38 | 58 | 84 |
| Italy | 54 | 70 | 84 |
| Netherlands | 114 | 125 | 92 |
| New Zealand | - | 103 | 89 |
| Sweden | - | 147 | 91 |
| United States | 39 | 54 | 80 |

## Selection Intensities

|  | Return to Service (%) | Selection Intensities |  |  |
| --- | --- | --- | --- | --- |
| Country |  | Milk | Fat | Protein |
| Australia | 3.9 | 1.03 | 1.13 | 1.32 |
| Canada | 5.4 | 1.01 | 0.69 | 1.07 |
| Denmark | 4.4 | 1.05 | 0.85 | 1.25 |
| France | 8.5 | 0.89 | 0.85 | 1.26 |
| Germany | 15.6 | 0.81 | 0.78 | 0.96 |
| Great Britain | 3.4 | 1.24 | 0.33 | 1.27 |
| Italy | 6.8 | 0.88 | 0.79 | 1.11 |
| Netherlands | 5.1 | 0.70 | 1.03 | 1.14 |
| New Zealand | 10.2 | 0.73 | 1.02 | 1.24 |
| Sweden | 4.9 | 1.26 | 1.08 | 1.64 |
| United States | 7.7 | 0.86 | 0.62 | 0.94 |

## Selection Intensities

|  | Return to Service (%) | Selection Intensities |  |  |
| --- | --- | --- | --- | --- |
| Country |  | Milk | Fat | Protein |
| Australia | 3.9 | 1.03 | 1.13 | 1.32 |
| Canada | 5.4 | 1.01 | 0.69 | 1.07 |
| Denmark | 4.4 | 1.05 | 0.85 | 1.25 |
| France | 8.5 | 0.89 | 0.85 | 1.26 |
| Germany | 15.6 | 0.81 | 0.78 | 0.96 |
| Great Britain | 3.4 | 1.24 | 0.33 | 1.27 |
| Italy | 6.8 | 0.88 | 0.79 | 1.11 |
| Netherlands | 5.1 | 0.70 | 1.03 | 1.14 |
| New Zealand | 10.2 | 0.73 | 1.02 | 1.24 |
| Sweden | 4.9 | 1.26 | 1.08 | 1.64 |
| United States | 7.7 | 0.86 | 0.62 | 0.94 |

## Selection Intensities

|  | Return to Service (%) | Selection Intensities |  |  |
| --- | --- | --- | --- | --- |
| Country |  | Milk | Fat | Protein |
| Australia | 3.9 | 1.03 | 1.13 | 1.32 |
| Canada | 5.4 | 1.01 | 0.69 | 1.07 |
| Denmark | 4.4 | 1.05 | 0.85 | 1.25 |
| France | 8.5 | 0.89 | 0.85 | 1.26 |
| Germany | 15.6 | 0.81 | 0.78 | 0.96 |
| Great Britain | 3.4 | 1.24 | 0.33 | 1.27 |
| Italy | 6.8 | 0.88 | 0.79 | 1.11 |
| Netherlands | 5.1 | 0.70 | 1.03 | 1.14 |
| New Zealand | 10.2 | 0.73 | 1.02 | 1.24 |
| Sweden | 4.9 | 1.26 | 1.08 | 1.64 |
| United States | 7.7 | 0.86 | 0.62 | 0.94 |

## Conclusions

**Reliability at PT decision time: ****80-92%**
**Mean bull age by country: ****66-77 months**
**PT bulls return to service by country: ****3.4-15.6%**** (Mean 6.9)**
**Selection intensities: ****.33-1.64**** **
**(Tended ~1)**
**Highest selection intensities were for  protein in all 11 countries**