USDA Estimated Relative Conception Rate Evaluation - 2006


Country (or countries) United States of America
Main trait group Male Fertility - Estimated Relative Conception Rate
Breed(s) JER, HOL
Trait definition(s) and unit(s) of measurement NR70 is the non-return rate at 70 days for first AI matings to cows during lactation (i.e. no heifer breedings). The trait is binary: success or failure on first service.

* First service is coded as a failure if another reproductive event (breeding (AI or natural service), heat, or diagnosis of 'not pregnant') is reported within 70 days of the mating. If no reproductive event is reported within 70 days, the breeding is coded as a success, even if another reproductive event is reported after day 70.
Method of measuring and collecting data Collected by Dairy Herd Improvement Associations.
Time period for data inclusion Restricted to the most recent three years of data.
The earliest breeding date included is: cutoff date – (3×365) – 70
(cutoff date is the last day of data included in the current evaluation).
Age groups (e.g. parities) included Breedings in all parities are included (heifer breedings are NOT included). Parity groups are 1, 2, 3, 4, 5, ≥6.
A maximum age limit of 14yr is imposed for non-active bulls. No age limit for active bulls.
Other criteria (data edits) for inclusion of records
  • Service-sire ID is required.
    Breed of service-sire must match breed of cow (no crossbreds).
  • First breeding must be within 15 to 365 DIM.
  • Third test-day can occur no later than 150 DIM .
    Of the first 3 tests, at least 2 must include valid* milk, fat%, and protein%.
    *Valid values for the first 3 tests are 10–240lbs for milk, and 2–8% for protein.
  • All lactation test days must be in the same herd.
    Last reported test day must be at least 70 days after the reported first breeding.
  • Herd average conception rate must be ≤62.5%.
    Herds must have >40% usable complete records (UCR; breeding lactation record is followed by a subsequent record of calving).*
    Herd average gestation length (GL) must be 270–290d and SD of herd GL must be <10d.*
    *UCR and GL edits use only records with GL of 265–308d or missing.
  • Herd-year (year=year of breeding) must have ≥10 breedings.
  • Service-sire must have ≥100 breedings within a given year to be included for that year.
Criteria for extension of records (if applicable) NA
Sire categories  
Environmental effects, pre-adjustments No
Method (model) of genetic evaluation ST BLUP repeatability animal model.
Environmental effects in the genetic evaluation model Fixed: herd-year-month of breeding, parity, DIM, service-sire birthyear, energy corrected milk (ECM calculation described in Clay and McDaniel, 2001).
Random: permanent environment of the cow, service-sire * herd, service-sire (ERCR).
Adjustment for heterogeneous variance in evaluation model No
Use of genetic groups and relationships No
Blending of foreign/Interbull information in evaluation NA
Genetic parameters in the evaluation See table below.
System validation  
Expression of genetic evaluations
If standardised (e.g. RBV), give standardisation formula in the appendix		 ERCR is a phenotypic predictor of bull fertility, expressed as a relative conception rate.
ERCR = (Solutions for service-sire × 100) rounded to nearest whole number.
Definition of genetic reference base
Next base change		  
Calculation of reliability 100 × [1 – (1 – (N ⁄ (N + 200))½) × 2.3]
(N = number of breedings)
Criteria for official publication of evaluations Only bulls with ≥300 matings are published.
Number of evaluations / publications per year  
Use in total merit index None
Anticipated changes in the near future Use of all services instead of only first service, an improved model, and revised edits.
Key reference on methodology applied
  • Clay, J.S. and B.T. McDaniel. 2001. Computing mating bull fertility from DHI nonreturn data. J. Dairy Sci. 84: 1238-1245.http://jds.fass.org/cgi/reprint/84/5/1238
  • Bull fertility summary section of DRMS web site: http://www.drms.org/sire.htm
  • Proceedings of NAAB Technical Conference. 2000. Computing estimates of fertility for mating bulls from DHI non-return data. John S. Clay. 45-49.
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: inquiry@aipl.arsusda.gov
web site: http://aipl.arsusda.gov

Effect

Variance

service-sire (ERCR)

0.001078

service-sire×herd

0.010780

permanent environment (PE)

0.004791

animal (cow)

0.004791

error

0.215600

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