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United States Department of Agriculture

Agricultural Research Service


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Title: Comparison of service-sire fertility evaluations formerly or currently available to the US dairy industry)

item Norman, H
item Hutchison, Jana - Edwards
item Wright, Janice

Submitted to: Journal of Dairy Science
Publication Type: Abstract Only
Publication Acceptance Date: 3/5/2009
Publication Date: 7/12/2009
Citation: Norman, H.D., Hutchison, J.L., Wright, J.R. 2009. Comparison of service-sire fertility evaluations formerly or currently available to the US dairy industry. Journal of Dairy Science. 92(E-Suppl. 1):122(abstr. 31). 2009.

Interpretive Summary:

Technical Abstract: A new service-sire fertility evaluation, Sire Conception Rate (SCR), was initiated in August 2008 to replace the previous evaluation, Estimated Relative Conception Rate (ERCR), used by the dairy industry for 20 yr. This study derived and compared evaluations from these 2 procedures using both an August 2008 and January 2009 data cutoff (using data from the same herds) with the Western Bull Fertility Analysis (WBFA). SCR and ERCR inputs were from 3 dairy records processing centers; WBFA data was from 1. The SCR model includes 10 effects to help predict bulls’ conception rate (CR). Minimum inseminations/bull in the last 4 yr to publish SCR was 300 for Holsteins (HO), 100 or 200 for other breeds. ERCR uses only first services, and WBFA and SCR use inseminations through fifth and seventh service, respectively. Comparing the January 2009 evaluations, the most bulls were summarized with SCR; number of HO bulls with SCR, ERCR, and WBFA were 2358, 956, and 1594; number of Jersey (JE) bulls were 210, 82, and 98. Mean of bull evaluations from all 3 methods were near zero. Standard deviations (SD) for HO and JE for SCR were 2.42 and 2.51, 1.76 and 1.88 for ERCR, and 2.02 and 2.72 for WBFA. Holsteins bulls that were <3, 3 to 4, 4 to 5, 5 to 6, and > 6 yr had mean SCR of -0.76, -0.12, 2.30, 1.48, and 1.31%, respectively. Comparable means for ERCR were 0.89, 0.10, 0.82, 0.06 and 0.02, and for WBFA were -0.14, -0.01, -0.13, 0.38, and 0.53. Standard deviations for SCR for these same were 2.20, 2.47, 2.29, 2.22, and 2.05. Standard deviations for ERCR were 1.68, 1.79, 1.74, 1.74, and 1.98, and for WBFA were 1.85, 1.96, 2.19, 2.10, and 1.93. Correlations between SCR and ERCR for HO and JE were 0.73 and 0.76. Correlations between SCR and WBFA were 0.65 and 0.68, and between ERCR and WBFA were 0.63 and 0.73. Correlations between August 2008 and January 2009 SCR were 0.95 and 0.94. Correlations between August 2008 and January 2009 ERCR were 0.91 and 0.90, and between the same for WBFA were 0.97 and 0.96.

Last Modified: 05/27/2017
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