2004

2004

2006

G. R. Wiggans*, L. L. M. Thornton*,1, R. R. Neitzel†, and N. Gengler‡

* Animal Improvement Programs Laboratory, ARS, USDA, Beltsville, MD† Brown Swiss Association, Beloit, WI‡ National Fund for Scientific Research, Brussels, Belgium and Gembloux Agricultural University, Belgium 1Presenter: laura@aipl.arsusda.gov

Abstract #341

Rear Legs (Rear View) for Brown Swiss and Guernsey

Breeds

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Why Rear Legs (Rear View)?

Mobility is major producer concern

Lameness is third most likely cause for culling

Not considering production

Selection could improve mobility and productive life

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International participation Holstein RLRV is reported from all participants

but CZE and NZL

Ayrshire RLRV is reported from AUS, CAN, DEU, DFS, and NOR

Jersey RLRV is reported from AUS, CAN, DNK, ITA, NLD, ZAF

Guernsey RLRV is only reported from AUS, CAN

Brown Swiss RLRV is not included as an INTERBULL trait

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Scoring Brown Swiss scored on

scale of 1 (low) to 9 (high)

Guernsey scored 1 to 50

Higher scores generally preferred, but extremes are not desired

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Score Frequency

1Brown Swiss scores multiplied by five 2Guernsey scores grouped by fives

0

500

1000

1500

2000

2500

3000

0 5 10 15 20 25 30 35 40 45 50

Score for Rear Legs (Rear View) 1,2

An

imal

s

Guernsey

Brown Swiss

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Scoring cont.Trait Description

Appearance of rear legsScore

Perpendicular to ground, may hock out, toe in

High

Straight track, no hock in or out, no toe in or out

Optimum

Hock in, slight toe outModerate

Severely hock in, toe outLow

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Scoring cont.

Hock in, toe out Correctconformatio

nPicture credit: http://www.ansci.umn.edu/dairy/documents/judging_dairy_cattle.pdf

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Data

99Unknown parent groups1

213228Sires with ≥5 daus

17,82723,353Pedigrees including ancestors

229417Herds

4,7497,676Cows

5,4378,503Records

GuernseyBrown Swiss

12 birth years/group

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Rear Legs (Rear View) Parameters

5.8

0.102

Brown Swiss

7.48.8Standard deviation

0.0780.11Heritability

GuernseyHolstein

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Genetic Correlation of Rear Legs (Rear View) with Linear

Type Traits

0.340.44−0.03Dairy form0.220.310.15Rear udder height

−0.110.010.10Udder depth

0.430.710.20Rear udder width

0.17−0.14−0.42

0.230.32

Holstein

0.060.24Fore udder attachment

−0.08−0.19Rump angle−0.46−0.11Rear legs (side view)

0.160.47Thurl width0.300.49Strength

GuernseyBrown SwissTrait

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Calculation of Evaluations

First: Evaluate final score & 15 linear traits with current system

Second: Evaluate rear legs (rear view)

Use only records with rear legs (rear view) in 17-trait system

•Allows use of correlated trait information•No heterogeneous variance adjustments•Only rear legs (rear view) evaluations

retained

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Cow evaluations

Brown Swiss

Guernsey

Records 5,7094,74

9Reliability, % 32.9 29.9Mean, PTA 0.01 0.08Minimum, PTA −1.50 −2.70Maximum, PTA 1.30 2.60Standard deviation 0.39 0.52

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Bulls with ≥5 daughters

Brown Swiss

Guernsey

Bulls 228 213Daughters 20.9 19.0Herds 12.8 10.4Reliability, % 49.6 44.7Mean, PTA 0.02 0.07Minimum, PTA −1.20 −1.70Maximum, PTA 1.30 2.20Standard deviation 0.43 0.61

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Further Research

Introduced in May 2006

Investigate trait inclusion in Feet & Legs Composite

Check impact on Net Merit

Second evaluation step may be unnecessary after more years of data accumulate