H. D. Norman, J. L. Hutchison, and P. M. VanRaden

Animal Improvement Programs Laboratory ARS, USDA, Beltsville, MD

Jana.Hutchison@ars.usda.gov

CDCB/AIPL Meeting (1) 2010J. L. Hutchison

Holstein service-sire fertility for heifer and cow breedings with conventional and sexed

semen

J. L. Hutchison 2010CDCB/AIPL Meeting (2)

Sire Conception Rate

Implemented in August 2008

Based on:

Last 4 years of breedings

Up to 7 conventional semen breedings

Parities 1 through 5

10 effects to predict bull conception rate

Sexed-semen breedings and heifer data not included

J. L. Hutchison 2010CDCB/AIPL Meeting (3)

Data

Derived 3 alternative models from SCR:

Sexed semen for cows

Conventional semen for heifers

Sexed semen for heifers

Service sire age groups condensed for sexed semen breedings due to limited number of bulls

Parity removed from models with heifer data

J. L. Hutchison 2010CDCB/AIPL Meeting (4)

Data

Based on January 2010 evaluation

Breedings from 2006 through 2009

Publishable Holstein bulls were included

Bulls with ≥300 breedings in ≥10 herds overall and ≥100 matings during the last 12 months

J. L. Hutchison 2010CDCB/AIPL Meeting (5)

Number of bulls

ModelJanuary 2010

Conventional, cow 2,309

Sexed, cow 25

Conventional, heifer 270

Sexed, heifer 114

J. L. Hutchison 2010CDCB/AIPL Meeting (6)

Mean number of matings/bull

ModelJanuary 2010

Conventional, cow 3,297

Sexed, cow 1,263

Conventional, heifer 3,321

Sexed, heifer 1,313

J. L. Hutchison 2010CDCB/AIPL Meeting (7)

Statistical summary

Model Mean SCR SD RELConventional, cow 0.000 2.21 79

Sexed, cow -0.012 2.39 73

Conventional, heifer

0.002 2.57 82

Sexed, heifer 0.002 4.34 75

J. L. Hutchison 2010CDCB/AIPL Meeting (8)

Correlations between SCR

Conventional, cow

Sexed, cow

Conventional, heifer

Sexed, heifer

Conventional, cow

— 0.18 0.67 0.10

Sexed, cow 0.24 — 0.16 0.75

Conventional, heifer

0.82 0.20 — 0.08

Sexed, heifer 0.13 1.02 0.11 —

Genetic correlation (rg) for true SCR below diagonal

J. L. Hutchison 2010CDCB/AIPL Meeting (9)

Correlations between SCR

Conventional, cow

Sexed, cow

Conventional, heifer

Sexed, heifer

Conventional, cow

— 0.18 0.67 0.10

Sexed, cow 0.24 — 0.16 0.75

Conventional, heifer

0.82 0.20 — 0.08

Sexed, heifer 0.13 1.02 0.11 —

Genetic correlation (rg) for true SCR below diagonal

J. L. Hutchison 2010CDCB/AIPL Meeting (10)

Correlations between SCR

Conventional, cow

Sexed, cow

Conventional, heifer

Sexed, heifer

Conventional, cow

— 0.18 0.67 0.10

Sexed, cow 0.24 — 0.16 0.75

Conventional, heifer

0.82 0.20 — 0.08

Sexed, heifer 0.13 1.02 0.11 —

Genetic correlation (rg) for true SCR below diagonal

J. L. Hutchison 2010CDCB/AIPL Meeting (11)

Correlations between SCR

Conventional, cow

Sexed, cow

Conventional, heifer

Sexed, heifer

Conventional, cow

— 0.18 0.67 0.10

Sexed, cow 0.24 — 0.16 0.75

Conventional, heifer

0.82 0.20 — 0.08

Sexed, heifer 0.13 1.02 0.11 —

Genetic correlation (rg) for true SCR below diagonal

J. L. Hutchison 2010CDCB/AIPL Meeting (12)

Correlations between SCR

Conventional, cow

Sexed, cow

Conventional, heifer

Sexed, heifer

Conventional, cow

— 0.18 0.67 0.10

Sexed, cow 0.24 — 0.16 0.75

Conventional, heifer

0.82 0.20 — 0.08

Sexed, heifer 0.13 1.02 0.11 —

Genetic correlation (rg) for true SCR below diagonal

J. L. Hutchison 2010CDCB/AIPL Meeting (13)

Conclusions

Fertility rankings for sexed semen differ considerably from conventional evaluations and warrants separate SCR

Combining cow and heifer breedings together in some manner would seem to be advantageous