# Presentation: 755035

## Country bias in international dairy bull evaluations

## MACE Evaluation Process

**Interbull combines yield evaluations from 27 national Holstein bull populations.**
**Estimated genetic correlations between evaluations from different populations are applied. **
**Results are reported on the scale of each participating country organization.**

## Investigation of Country Bias

**Full brothers are expected to have the same genetics on average.**
**Full brothers with daughters in different countries should have the same MACE evaluations (on average).**
**Do full brother evaluations reveal country bias?**

## Data

**May 2005 Interbull evaluations of Holsteins for milk, fat, and protein yields, and SCS**
**Eligible bulls**
**≥****1 eligible full-brother **
**Daughters in only one eligible country**
**Eligible countries**
**Represented in ≥25 multi-country families**
**18**** countries for yield**
**15**** countries for SCS**

## Data

|  |  | Bulls | Families |
| --- | --- | --- | --- |
| Yield | All families | 24,652 | 10,191 |
|  | Multi-country families | 9916 | 3598 |
| SCS | All families | 22,842 | 9022 |
|  | Multi-country families | 9489 | 3283 |

## Multi-Country Families

| Home Country | Families |  | Home Country | Families |  |
| --- | --- | --- | --- | --- | --- |
|  | Yield | SCS |  | Yield | SCS |
| Australia | 85 | 54 | Italy | 237 | 223 |
| Canada | 641 | 628 | Japan | 763 | 754 |
| Czech Rep. | 121 |  | New Zealand | 44 | 39 |
| Denmark | 505 | 485 | Poland | 70 |  |
| France | 1162 | 1089 | South Africa | 32 | 30 |
| Germany | 939 | 845 | Spain | 215 | 207 |
| Gr. Britain | 468 | 432 | Sweden | 48 | 44 |
| Hungary | 67 | 54 | The Netherlands | 637 | 599 |
| Ireland | 159 |  | United States | 1631 | 1596 |

## Ties Between Countries

| Home Country | Ties |  | Home Country | Ties |  |
| --- | --- | --- | --- | --- | --- |
|  | Yield | SCS |  | Yield | SCS |
| Australia | 122 | 78 | Italy | 328 | 302 |
| Canada | 773 | 751 | Japan | 979 | 959 |
| Czech Rep. | 153 |  | New Zealand | 55 | 48 |
| Denmark | 646 | 595 | Poland | 81 |  |
| France | 1481 | 1364 | South Africa | 48 | 42 |
| Germany | 1176 | 1036 | Spain | 302 | 280 |
| Gr. Britain | 650 | 582 | Sweden | 54 | 49 |
| Hungary | 82 | 66 | The Netherlands | 802 | 736 |
| Ireland | 232 |  | United States | 1978 | 1910 |

## US Ties to Other Countries

| Home Country | Ties |  | Home Country | Ties |  |
| --- | --- | --- | --- | --- | --- |
|  | Yield | SCS |  | Yield | SCS |
| Australia | 32 | 20 | Italy | 51 | 51 |
| Canada | 337 | 333 | Japan | 491 | 490 |
| Czech Rep. | 11 |  | New Zealand | 15 | 15 |
| Denmark | 56 | 51 | Poland | 6 |  |
| France | 476 | 473 | South Africa | 8 | 8 |
| Germany | 140 | 140 | Spain | 58 | 57 |
| Gr. Britain | 109 | 104 | Sweden |  |  |
| Hungary | 18 | 15 | The Netherlands | 154 | 153 |
| Ireland | 16 |  | United States | 1978 | 1910 |

## Model

**Full-brother family (absorbed)**
**Country of bull daughters**
**Analysis of MACE evaluations on the US scale **
**Difference between evaluations based on foreign daughters and those based on domestic (US) daughters**
**Evaluations on several other country scales also analyzed**

## Results

**Overall significance for country differences on all country scales for yield traits**
**Overall, no significance for SCS**
**For SCS, South African bulls significantly disadvantaged on all scales**

## Results for US-Scale Evaluations

| Countries with evaluations more favorable (blue) or less favorable (pink) than those from USA (P<0.05) |  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- |
| Milk |  | Fat |  | Protein |  | SCS |  |
| AUS ESP GBR JPN | DEU FRA ITA  | AUS ZAF | GBR | AUS GBR ZAF | DEU JPN | ZAF |  |
| AUS=Australia; DEU=Germany; ESP=Spain; FRA=France; GBR=United Kingdom; ITA=Italy; JPN=Japan; USA=United States of America; ZAF=South African Republic;. |  |  |  |  |  |  |  |

## Results for Other Evaluation Scales

| Milk: | Domestic bulls disadvantaged on scales of CAN, ITA, and NLD similarly to US bulls on the US scale |
| --- | --- |
|  | Domestic bulls generally favored on scales of AUS and DEU |
|  |  |
|  |  |
|  |  |

## Results for Other Evaluation Scales

| Milk: | Domestic bulls disadvantaged on scales of CAN, ITA, and NLD similarly to US bulls on the US scale |
| --- | --- |
|  | Domestic bulls generally favored on scales of AUS and DEU |
| Fat: | Bulls from AUS, GBR, and ZAF were favored on scales of CAN, FRA, ITA, and NLD |
|  | All but NZL and ZAF bulls disadvantaged on AUS scale |
|  |  |

## Results for Other Evaluation Scales

| Milk: | Domestic bulls disadvantaged on scales of CAN, ITA, and NLD similarly to US bulls on the US scale |
| --- | --- |
|  | Domestic bulls generally favored on scales of AUS and DEU |
| Fat: | Bulls from AUS, GBR, and ZAF were favored on scales of CAN, FRA, ITA, and NLD |
|  | All but NZL and ZAF bulls disadvantaged on AUS scale |
| Protein results similar to milk |  |

## Possible Complications

**Genetic correlations**
**Parent averages (completeness and phantom grouping)**
**National animal model vs. sire-MGS MACE**
**Preferential treatment**
**Pre-selection (markers, etc.)**

## Conclusions	

**Apparent biases for yields but not SCS**
**Some countries appear disadvantaged while others are favored across all country scales**
**Caused by shortcomings in national systems or international system?**
**Source of biases unknown and may be different for different country pairs**