Introducing CDCB Health Evaluations Kristen Parker Gaddis, CDCB Geneticist

Beginning in April 2018, CDCB will provide official genetic and genomic evaluations for six direct health traits.

What are the traits?

Selection of health events Based on several considerations Preliminary research Incidence rate Reporting consistency Cost Heritability

Health Event Definitions Hypocalcemia: typically results after calving due to low total blood calcium levels; also commonly referred to as milk fever Displaced abomasum: enlargement of the abomasum with fluid and/or gas which causes movement to the left or right side of the abdominal cavity, usually requiring veterinary intervention Ketosis: build up of ketone bodies typically occurring due to negative energy balance in early lactation

Health Event Definitions (continued) Mastitis: infectious disease causing inflammation of the mammary gland; one of the most common and costly diseases of dairy cattle Metritis: infection of the endometrium (lining of the uterus) after calving Retained placenta: retention of fetal membranes more than 24 hours after calving

Editing & Validating the data Producer-reported data from U.S. herds Editing procedures were researched and developed to ensure we are using the most accurate data General phenotypic edits developed by AGIL researchers Additional constraints put in place and outlined in peer-reviewed article* Compared the incidences with those found in designed and large-scale studies * Parker Gaddis et al., 2012

Trait statistics Calculated with research data from DRMS on Holsteins Event Incidence Heritability* Hypocalcemia 1.3% 0.6% Displaced abomasum 2.1% 1.1% Ketosis 3.9% 1.2% Mastitis 10.2% 3.1% Metritis 6.2% 1.4% Retained placenta 3.6% 1.0% * Heritability calculated on observed scale

How are these traits evaluated?

Genetic Evaluations Using the same tested methods as other CDCB genetic and genomic evaluations Developed by AGIL researchers International validation with Interbull

Genomic Evaluations Uses same methods and programs as other traits Same 60,671 markers used for routine genomic evaluations

How do these traits relate to current traits?

Current Traits We have been making progress in health traits Indirect selection with productive life, livability, etc. Correlations between PTAs for health traits and traits in NM$

PTA Correlations Event Protein PL LIV SCS DPR CCR HCR Hypocalcemia 0.18 0.15 0.19 -0.29* 0.003 0.01 0.02 Displaced abomasum 0.23 0.35* 0.47* -0.13 0.32* 0.28* 0.24 Ketosis 0.03 0.33 0.27 -0.19 0.59* 0.49* 0.07 Mastitis 0.06 0.39* 0.22* -0.68* 0.20* 0.21* Metritis 0.05 0.26* -0.09 0.46* 0.41* 0.23* Retained placenta -0.03 0.17* 0.13* -0.10 0.14* 0.12* * Significant P < 0.05

Relationships with current traits No significant correlation with yield trait Significant correlations with new health traits: Productive life and Livability Mastitis and SCS (-0.68) Fertility traits

How will the traits be presented?

Trait Presentation Traits will be presented as disease RESISTANCE Hypocalcemia resistance Displaced abomasum resistance Ketosis resistance Mastitis resistance Metritis resistance Retained placenta resistance

Trait Expression Percentage points of event incidence above or below the breed average Higher, positive values = more resistant Lower, negative values = less resistant

Examples Resistance of clinical mastitis ≈ 90% Bull A PTA = + 3.0 Incidence rate ≈ 10% Bull A PTA = + 3.0 Bull B PTA = - 4.0 Expect 93% resistance of clinical mastitis among Bull A’s daughters (7% incidence rate) Expect 86% resistance of clinical mastitis among Bull B’s daughters (14% incidence rate)

Economic Value Utilizing the most recent estimates of direct treatment costs from literature NM$ already accounts for related losses (e.g., decreased production and fertility) Abnormal & sick test day adjustments Liang categories: veterinary and treatment costs, producer labor, milk loss, discarded milk, culling cost, extended days open, and on-farm death

Estimated direct cost per case* Economic estimates Event Liang et al., 2017 Donnelly Adjusted test day Estimated direct cost per case* Hypocalcemia - $38 - $4 $34 Displaced abomasum $82 $275 + $19 $197 Ketosis $23 $33 + $0 $28 Mastitis $104 $39 + $3 $75 Metritis $94 $117 + $7 $112 Retained placenta $47 $80 + $4 $68

Average Genomic Reliability Event Young bulls Proven bulls Hypocalcemia 40.0 44.2 Displaced abomasum 41.8 47.1 Ketosis 41.2 46.2 Mastitis 49.4 56.3 Metritis 42.2 48.1 Retained placenta 41.6 46.7

How can we keep improving?

No man…or cow?…is an island

Accurate health evaluations Research Dairy Records Providers Dairy Records Processing Centers Producer-reported health events CDCB Working Groups Collaboration with AGIL

Dairy Producers The most critical component by actively reporting health events Develop a robust national database Collection of more data will improve evaluations

Data Security Security of raw data is of the utmost importance Several levels of IT security put in place Only PTAs will be published by CDCB based on data contributed to the cooperator database Raw data or related information will never be released to third parties Herd-based statistics will not be published

Dairy Records Providers & Processing Centers Building a robust national database depends on transfer of the data to CDCB Not a simple process Collaboration & cooperation

Research & Development AGIL – provided support, consultation, and countless hours of help in the process of development and testing CDCB Working Groups – discussions and recommendations for critical decisions

Thank you! Dairy Producers DRPC’s and DRP’s CDCB committee members AGIL

Thank You!