USDA Type Evaluation Description (Ayrshire, Brown Swiss, Guernsey, Jersey) - 2007


Country (or countries) USA
Main trait group Type
Breed(s) AYS, JER, BSW, GUE
Trait definition(s) and unit(s) of measurement Stature, strength, body depth, dairy form, rump angle, thurl width, rear leg side view, foot angle, fore udder attachment, rear udder height, rear udder width, udder cleft, udder depth, teat placement, teat length, final score. (no Body Depth for JER or BSW, rear legs/rear view only for GUE).
Method of measuring and collecting data Breed Association classifiers score each trait visually on a 50-point linear scale. AYS - traits are scored on a 9-point scale by Select Sire appraisers. JER 80-point scale for stature.
Time period for data inclusion Classifications from 1980 and later plus pedigree from birth year 1970 and later.
Age groups (e.g. parities) included AYS- age <= 60 months; BSW- age <= 68 months; GUE- parity 1-3; JER- parity 1-2.
Other criteria (data edits) for inclusion of records Valid sire identification required. AYS-Appraisal in first or second lactation required. JER- Appraisal in first lactation required.
Criteria for extension of records (if applicable)  
Sire categories AI and NS included.
Environmental effects, pre-adjustments Age, Stage of lactation.
Method (model) of genetic evaluation MT AM
Environmental effects in the genetic evaluation model Herd-appraisal date-parity (F) herd x sire (R), PE (R)
Adjustment for heterogeneous variance in evaluation model Within iteration estimates of variances are used to adjust for heterogenity of variance.
Use of genetic groups and relationships Unknown parents grouped by birth year in two year groups.
Blending of foreign/Interbull information in evaluation None.
Genetic parameters in the evaluation See PART 2 for heritability/genetic variance estimates; for multiple-trait genetic evaluations, provide genetic correlation estimates between traits separately
System validation Means and SD for all variables are calculated and examined overall. Means for new bulls, changes for high bulls, largest changes, and key statistics for recent AI bulls are checked.
Expression of genetic evaluationsIf standardised (e.g. RBV), give standardisation formula in the appendix PTA (no standardization)(PTA = .5*BV)
Definition of genetic reference base
Next base change		 Evaluations of cows born in 2000 average 0, (stepwise, 5 year)
Next base change, first evaluation of 2010 (when base will be evaluations cows born in 2005).
Calculation of reliability Iterative method that estimates contributions from parents, own records, and progeny.
Criteria for official publication of evaluations At least 5 daughters with usable classification record.Interbull evaluations are reported as official in the US if: they include data on udder support from an additional country; the US has no evaluation; or Interbull excludes US data and the Interbull evaluation has higher reliability
Number of evaluations / publications per year Four, in February, May, August, and November
Use in total merit index Net merit dollars (NM$) = (4.81* protein) + = (2.54*fat) + (26*productive life) - (166*SCS) - (12*size) + (33*udder) + (15* feet & legs)+ (17*Daughter Pregnancy Rate). Note: Type traits are composites, others are expressed as PTA, and weights are $/PTA unit. SCS is the deviation from breed average, i.e. not expressed including breed average.
Anticipated changes in the near future  
Key reference on methodology applied
  • Gengler, N., Dusseldorf, T., Wiggans, G.R., Wright, J.R., and Druet, T. Heterogeneity of (co)variance components for Jersey type traits. J. Dairy Sci. 84:(July). Online. 2001.Available: http://www.adsa.org/jds/papers/0385/JDS0385.html
  • Gengler, N., Wiggans, G.R., and Wright, J.R. Animal model genetic evaluation of type traits for five dairy cattle breeds. J. Dairy Sci. 82 (June). Online. 1999. Available: http://www.adsa.org/manuscripts/jds8311/.
  • Gengler, N., Wiggans, G.R., Wright, J.R., and Druet, T. Simultaneous accounting for heterogeneity of (co)variance components in genetic evaluation of type traits. J. Dairy Sci. 84(Suppl. 1):247 (abstr. 1022). 2001. Available: http://www.adsa.org/jointabs/iaafs110.pdf.
Key organization: name, address, phone, fax, e-mail, web site Animal Improvement Programs Laboratory
USDA, Agricultural Research Service
Building 005, Room 306, BARC-West
10300 Baltimore Avenue Beltsville, Maryland 20705-2350
U.S.A.
Tel: 301-504-8334 Fax: 301-504-8092
E-mail: wiggans@aipl.arsusda.gov
web site: http://aipl.arsusda.gov

Genetic parameters for Ayrshire

Trait Definition h2 geneticvariance
Stature   .54 31.5
Chest Width Strength .31 11.4
Body Depth   .29 9.1
Angularity Dairy Form .20 8.4
Rump Angle   .28 8.4
Rump Width Thurl Width .35 13.4
Rear Leg Set Rear Leg (side view) .15 5.3
Rear Leg Rear View      
Foot Angle   .15 7.0
Fore Udder   .21 10.2
Rear Udder Height   .26 11.2
Udder Support Udder Cleft .23 10.1
Udder Depth   .31 12.5
Front Teat Placement   .24 11.4
Teat Length   .30 13.0
Rear Teat Placement      
Overall Conformation Score Final Score .27 2.5
Overall Udder Score   .26  
Overall Feet & Leg Score   .15  

Genetic parameters for Brown Swiss

Trait Definition h2 geneticvariance
Stature   .43 17.8
Chest width Strength .20 6.6
Body depth   .25 8.3
Angularity Dairy Form .18 7.6
Rump angle   .27 9.9
Rump Width Thurl Width .18 4.4
Rear Leg Side View Rear Leg (side view) .18 5.5
Pasterns/Foot Angle Foot Angle .13 5.3
Deep Heel (Hoof Height)      
Fore Udder Attachment   .22 10.9
Rear Udder Attachment Height Rear Udder Height .22 9.1
Rear Udder Attachment Width Rear Udder Width .19 8.0
Udder Support Udder Cleft .22 10.3
Udder Depth   .34 12.4
Front Teat Placement   .27 11.3
Teat Length   .34 15.1
Rear Teat Placement      
Overall Conformation Score Final Score .29 2.3
Overall Udder Score   .29  
Overall Feet & Leg Score   .15  

Genetic parameters for Guernsey

Trait Definition h2 geneticvariance
Stature   .49 27.6
Chest Width Strength .22 8.5
Body Depth   .32 12.2
Angularity Dairy Form .28 13.3
Rump Angle   .41 18.9
Rump Width Thurl Width .29 8.9
Rear Leg Set Rear Leg (side view) .16 5.3
Rear Leg Rear View   .08 4.3
Foot Angle   .10 3.6
Fore Udder   .29 16.2
Rear Udder Height   .28 13.3
Udder Support Udder Cleft .21 9.5
Udder Depth   .40 18.5
Front Teat Placement   .31 12.5
Teat Length   .34 12.2
Rear Teat Placement      
Overall Conformation Score Final Score .21 5.4
Overall Udder Score   .32  
Overall Feet & Leg Score   .10  

Genetic parameters for Jersey

Trait Definition h2 geneticvariance
Stature   .37 11.2
Chest Width Strength .21 6.2
Body Depth      
Angularity Dairy Form .21 8.0
Rump Angle   .22 7.3
Rump Width Thurl Width .18 4.5
Rear Leg Set Rear Leg (side view) .07 2.0
Rear Leg Rear View      
Foot Angle   .10 3.7
Fore Udder   .19 8.1
Rear Udder Height   .26 11.5
Udder Support Udder Cleft .17 5.1
Udder Depth   .27 11.9
Front Teat Placement   .20 7.8
Teat Length   .19 5.5
Rear Teat Placement      
Overall Conformation Score Final Score .19 6.2
Overall Udder Score   .23  
Overall Feet & Leg Score   .09  

Updated: This file last modified 02/28/24.