Where do your herd’s service sires rank?

Kathy Lee, Michigan State University Extension - September 05, 2013

Knowing where service sires rank relative to AI bulls being marketed is helpful in determining if the sires meet your herd’s genetic goals.

Net Merit (NM$) is a tool that can be used on dairy farms when making sire selection decisions. NM$ estimates lifetime profit based on incomes and expenses relevant for today’s dairy producers. Traits included in NM$ are: fat (lb.), protein (lb.), productive life (mo.), somatic cell score, udder composite, feet/leg composite, body size composite, daughter pregnancy rate and calving ability ($). More information about NM$ is reported in a previous Michigan State University Extension News article.

NM$ and other genetic evaluations for production and health/fitness traits are updated three times each year in April, August and December. Beginning in April 2013, dairy genetic evaluations have been calculated by the Council on Dairy Cattle Breeding (CDCB). They are labeled USDA-CDCB. The CDCB is comprised of various segments of the dairy industry including artificial insemination (AI) organizations, DHIA (Dairy Herd Information Associations), dairy processing centers and breed registry associations.

The genetic merit of bulls marketed through AI organizations continues to improve with each release of updated genetic evaluations. Consequently, sire selection goals set by dairy producers a year ago may be outdated today.

The following table lists the NM$ values for various percentile ranking levels for each breed. Knowing where service sires rank relative to other active AI bulls is helpful in determining if the sires meet the herd’s genetic goals. To maximize genetic improvement using NM$ as your selection index, it is recommended that the service sires for your herd have an average at or above the 80^th percentile.

NM$ levels of top percentiles for AI sires by breed. Aug. 2013 USDA-CDCB Sire Summary


	Percentile Rank
	60	70	80	85	90	95
Breed	Net Merit $ Level
Ayrshire (19)^a	265	271	283	336	349	378
Brown Swiss (36)	238	280	320	386	424	430
Guernsey (23)	179	235	301	362	417	456
Holstein (588)	414	452	496	526	560	596
Jersey (122)	322	354	393	424	442	473

^a Number of bulls in the current active AI population for each breed are in parentheses.

Dairy producers can select from a growing number of service sires. The availability of genomic-tested young sires has increased significantly. To show the trends in the number of genomic-tested young sires being marketed in the past 4 years, data from the August genetic releases from 2010 to 2013 are listed below.

Year	Number Bulls
2010	493
2011	720
2012	920
2013	1,211

To ensure that a herd’s replacement heifers will be genetically superior, sire selection criteria should be reviewed and updated periodically. It is important to communicate these goals with semen sales representatives also.

Net Merit $ can be used as a key selection tool to identify high ranking service sires. Use the percentile ranking information to determine where your current group of service sires rank.

This article was published by Michigan State University Extension. For more information, visit https://extension.msu.edu. To have a digest of information delivered straight to your email inbox, visit https://extension.msu.edu/newsletters. To contact an expert in your area, visit https://extension.msu.edu/experts, or call 888-MSUE4MI (888-678-3464).