Resistance to Ketosis (KETO)

KETO measures the resistance to Ketosis

Benefits of Trait

Introduced in April 2018, genetic and genomic evaluations for resistance to ketosis (KETO) are provided for Holstein and Jersey males and females. Evaluations are expressed in percentage points of resistance above and below the breed average.

Resistance to Ketosis (KETO)

The KETO predicted transmitting ability (PTA) represents the expected resistance of an animal’s offspring to ketosis in a herd with average management conditions. Evaluations are expressed in percentage points of resistance above and below the breed average. Larger, positive values are more favorable.

Percentage points

The average resistance rate is equal to 96.1% in U.S. Holsteins. The resistance rate is equivalent to the incidence rate subtracted from 100.

Daughters of a Holstein bull with a KETO PTA of +2.0% are expected to have an average resistance rate to ketosis of 98% (assuming the breed average resistance is approximately 96%). Daughters of a Holstein bull with a KETO PTA of -2.0% are expected to have an average resistance of 94%. Daughters from the bull with PTA -2.0% are expected to have over three times the number of cases of ketosis as daughters from the bull with PTA of +2.0%

BreedMean GL for CowsMean GL for HeifersMean GL for the
current base year (2010)

Holsteins: April 3, 2018
Jerseys: April 7, 2020

KETO is currently available for Holsteins and Jerseys. As more health data become available, evaluations can be provided for additional breeds.

KETO is included in selection indices for Holsteins and Jerseys as part of the Heath $ sub-index.

Estimated heritability is 1.2% for resistance to ketosis (observed scale).

Young genomic bulls are expected to have reliabilities averaging 41% for resistance to ketosis, and progeny tested bulls are expected to have genomic reliabilities averaging 46%. As additional data is accumulated, reliabilities will increase.

BreedAverage Reliability for GL of
Young Genotyped Bulls by Breed

The only significant (P < 0.05) correlation with PTA for resistance to ketosis included daughter pregnancy rate (DPR) PTA at 0.50 and cow conception rate (CCR) PTA at 0.49.

CDCB KETO evaluations were developed using producer-recorded data collected through Dairy Herd Information (DHI) affiliates from herds across the U.S. Strict editing was applied to ensure only the most reliable data was included for the development of genetic evaluations. The edited data included a total of 1.3 million KETO records from over 740,000 cows. These health records are used in conjunction with lactation data available in the CDCB cooperator database.

The standard deviation (variation) for KETO PTA is 0.9%. Because 1 and 2 standard deviations normally include 68% and 95% of observations, respectively, we assume about 68% of bulls will have a KETO PTA between -0.9% and +0.9% while 95% of the bulls will range from -1.8% to +1.8%.

KETO PTAs range from 3.1 percentage points below to 2.1 percentage points above average in evaluated Holstein bulls born since 1990 with reliabilities of ≥90% (December 2017).

Pre-release analysis indicates the active AI Holstein sires in December 2017 (614 bulls) range from -1.4% to +1.3%, with the average at approximately 0.1 percentage points.

Future Development

In the future, further model improvements and development will be researched and tested. This may include the development of a multi-trait model that incorporates multiple metabolic disorders.

Related Publications
Oetzel, G.R. 2007. Herd-Level Ketosis – Diagnosis and Risk Factors. In Proceedings of the 40th annual conference of bovine practitioners. Vancouver, Canada. 67–91.
Donnelly, M. R., A. R. Hazel, B. J. Heins, & L. B. Hansen, 2018. Health treatment cost of Holsteins in 8 high-performance herds. J. Dairy Sci. (in preparation).
Liang, D., L.M. Arnold, C.J. Stowe, R.J. Harmon, & J.M. Bewley, 2017. Estimating US dairy clinical disease costs with a stochastic simulation model. J. Dairy Sci. 100(2): 1472–1486.
Parker Gaddis, K.L., J.B. Cole, J.S. Clay, and C. Maltecca. 2012. Incidence validation and relationship analysis of producer-recorded health event data from on-farm computer systems in the United States. J. Dairy Sci. 95:5422–5435. doi:10.3168/jds.2012-5572.

Information last updated March 2018.