Abstract 341 Rear Legs Rear View for Brown

Abstract #341 Rear Legs (Rear View) for Brown Swiss and Guernsey Breeds 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 1 Presenter: laura@aipl. arsusda. gov 2006 2004

Why Rear Legs (Rear View)? w Mobility is major producer concern w Lameness is third most likely cause for culling - Not considering production w Selection could improve mobility and productive life ADSA/ASAS Joint Meeting 2006 (2) Wiggans et al. 2006 2004

International participation w Holstein RLRV is reported from all participants but CZE and NZL w Ayrshire RLRV is reported from AUS, CAN, DEU, DFS, and NOR w Jersey RLRV is reported from AUS, CAN, DNK, ITA, NLD, ZAF w Guernsey RLRV is only reported from AUS, CAN w Brown Swiss RLRV is not included as an INTERBULL trait ADSA/ASAS Joint Meeting 2006 (3) Wiggans et al. 2006 2004

Scoring w Brown Swiss scored on scale of 1 (low) to 9 (high) w Guernsey scored 1 to 50 w Higher scores generally preferred, but extremes are not desired ADSA/ASAS Joint Meeting 2006 (4) Wiggans et al. 2006 2004

Score Frequency 3000 Animals 2500 Guernsey Brown Swiss 2000 1500 1000 500 0 0 5 10 15 20 25 30 35 40 45 50 Score for Rear Legs (Rear View) 1, 2 1 Brown Swiss scores multiplied by five ADSA/ASAS Joint Meeting 2006 (5) 2 Guernsey scores grouped by fives Wiggans et al. 2006 2004

Scoring cont. Trait Description Score Low Appearance of rear legs Severely hock in, toe out Moderate Hock in, slight toe out Optimum Straight track, no hock in or out, no toe in or out Perpendicular to ground, may hock out, toe in High ADSA/ASAS Joint Meeting 2006 (6) Wiggans et al. 2006 2004

Scoring Hock in, toe out cont. Correct conformation Picture credit: http: //www. ansci. umn. edu/dairy/documents/judging_dairy_cattle. pdf ADSA/ASAS Joint Meeting 2006 (7) Wiggans et al. 2006 2004

Data Brown Swiss Guernsey Records 8, 503 5, 437 Cows 7, 676 4, 749 417 229 23, 353 17, 827 228 213 9 9 Herds Pedigrees including ancestors Sires with ≥ 5 daus Unknown parent groups 1 12 birth years/group ADSA/ASAS Joint Meeting 2006 (8) Wiggans et al. 2006 2004

Rear Legs (Rear View) Parameters Holstein Brown Swiss Guernsey Heritability 0. 11 0. 102 0. 078 Standard deviation 5. 8 7. 4 8. 8 ADSA/ASAS Joint Meeting 2006 (9) Wiggans et al. 2006 2004

Genetic Correlation of Rear Legs (Rear View) with Linear Type Traits Trait Strength Thurl width Rear legs (side view) Rump angle Fore udder attachment Udder depth Rear udder height Dairy form Rear udder width ADSA/ASAS Joint Meeting 2006 (10) Holstein 0. 32 0. 23 − 0. 42 − 0. 14 0. 17 0. 10 0. 15 − 0. 03 0. 20 Brown Swiss Guernsey 0. 49 0. 30 0. 47 0. 16 − 0. 11 − 0. 46 − 0. 19 − 0. 08 0. 24 0. 06 0. 01 − 0. 11 0. 31 0. 22 0. 44 0. 34 0. 71 0. 43 Wiggans et al. 2006 2004

Calculation of Evaluations w First: Evaluate final score & 15 linear traits with current system w 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 ADSA/ASAS Joint Meeting 2006 (11) Wiggans et al. 2006 2004

Cow evaluations Brown Swiss Guernsey Records 5, 709 4, 749 Reliability, % 32. 9 29. 9 Mean, PTA 0. 01 0. 08 Minimum, PTA − 1. 50 − 2. 70 Maximum, PTA 1. 30 2. 60 Standard deviation 0. 39 0. 52 ADSA/ASAS Joint Meeting 2006 (12) Wiggans et al. 2006 2004

Bulls with ≥ 5 daughters Brown Swiss Guernsey Bulls 228 213 Daughters 20. 9 19. 0 Herds 12. 8 10. 4 Reliability, % 49. 6 44. 7 Mean, PTA 0. 02 0. 07 Minimum, PTA − 1. 20 − 1. 70 Maximum, PTA 1. 30 2. 20 Standard deviation 0. 43 0. 61 ADSA/ASAS Joint Meeting 2006 (13) Wiggans et al. 2006 2004

Further Research w Introduced in May 2006 w Investigate trait inclusion in Feet & Legs Composite w Check impact on Net Merit w Second evaluation step may be unnecessary after more years of data accumulate ADSA/ASAS Joint Meeting 2006 (14) Wiggans et al. 2006 2004