Frequently Asked Questions

In 2013, the Council on Dairy Cattle Breeding (CDCB) assumed full responsibility to maintain the national cooperator database, compute results and distribute genomic and genetic evaluations. Previously the United States Department of Agriculture performed these service functions. A Non-funded Cooperative Agreement implemented on March 27, 2013, clarified that USDA would focus on world-class genetic research and CDCB was responsible for the U.S. database and genetic evaluations. 

USDA has a critical role in the U.S. dairy genetic system – providing cutting-edge research for continuous improvement. USDA is the federal department that provides U.S. leadership on agriculture, food and related topics based on public policy and the best available science. USDA’s Animal Genomics and Improvement Laboratory (AGIL) discovers improved methods for the genetic and genomic evaluation of economically important traits of dairy animals and small ruminants and conducts fundamental genomics-based research aimed at improving their health and productive efficiency. This research supports top-quality genetic evaluations, data integrity and implementation of technology and new scientific learnings. 

Other USDA agencies provide additional support, through research funding, economic analysis and current dairy herd health information.

Until 2013, USDA also performed the service functions related to the U.S. dairy database and genetic evaluations. The Council on Dairy Cattle Breeding (CDCB) assumed full responsibility in 2013 to maintain the national cooperator database, compute results and distribute genomic and genetic evaluations. 

Lifetime Net Merit Dollars ($) was first published in 1994, combining the yield traits (milk, fat and protein) with productive life and somatic cell score, in a weighting that reflected the traits’ impact on herd profitability. As of the August 2020 update, 36 traits are currently included in Net Merit.

The predicted transmitting ability (PTA) for Feed Saved represents the expected pounds of feed saved per lactation, above or below the breed average, based on body weight composite (BWC) and residual feed intake (RFI) evaluations. The unit of measurement is pounds of dry matter intake. Larger, positive values are more favorable. Genetic and genomic evaluations for Feed Saved (FSAV) are provided for Holstein males and females. 

That depends. If the bull is not an A.I. bull, then the costs would only be the nomination fees at CDCB. However, if semen is collected and the bull is marketed on values from the U.S. genomic evaluation, the bull is subject to both CDCB and NAAB fees.

No. TPI is a genetic index developed by Holstein Association USA specific for Holsteins. The national selection index in the U.S. is Net Merit $.

The Council for Dairy Cattle Breeding (CDCB) is the national calculation center for the U.S. genetic evaluations and caretaker of the national cooperator database of genotypes and phenotypic data.

The National Association of Animal Breeders (NAAB) is the trade association that represents the U.S. artificial insemination (A.I.) industry. The NAAB also manages the dairy cross reference database which provides the CDCB with bull identification numbers (NAAB codes) and bull status information for the U.S. genetic evaluations of bulls for A.I.

Country code 840 is used for animal from the United States that have been tagged with an ICAR-accredited RFID device. Country code 840 is not synonymous to country code USA; thus, the two codes cannot be used interchangeably.

All A.I. bulls enrolled in the dairy cross reference database at NAAB have a bull status code. This code represents the activity status of the bull. Bulls with the A,F or G code are actively being collected and marketed, so they will appear on industry ranking lists. 

No, unfortunately not. While technically 1 kg equals 2.2 pounds, that direct conversion does not work for breeding values. The United States expresses genetic merit in PTAs, or Predicted Transmitting Abilities, and other countries use EBVs, or Estimated Breeding Values. In addition, each country expresses the genetic merit of an animal as a deviation of the national population average. Therefore, direct comparison of breeding values between countries and mathematic conversion of pounds (lbs) to kg will not be accurate.

The United States expresses the actual predicted value that a bull or dam transmits to its offspring, which is 50% of the total. The other half comes from the other parent, which is unknown until breeding.

Genomic tests are offered as part of products and herd solutions from a variety of organizations. The price for a genomic test generally ranges from $20 to $50 (US$). Testing at a higher density may come at a higher price.

Genomic tests are offered by a variety of companies, including breed associations, laboratories such as Zoetis and Neogen, and most A.I. companies. Company websites offer detailed information on their testing product, and company representatives can help you get started. You will most likely be sent a testing kit upon purchase with directions on how to take the biological sample and where to send it.

A selection index allows selection for multiple traits without ruling out too many bulls from your breeding program. Selection indices are weighted, which means that more or less emphasis can be placed on specific traits. Selection indexes provide a more balanced way of selection that is appropriate to the continuous nature of biological traits. Individual trait cut-offs can result in the entire animal being rejected based on one or a few traits – eliminating the chance to take advantage of traits that may be beneficial and more important to the herd’s breeding objective. 

The United States has made great genetic progress in calving ease and adjusted its base levels for calving ease in 2020 to match the improved population average. The population average for Sire Calving Ease (SCE) in Holsteins is 2.2% with a max of 5-6%. The previous threshold recommended for heifers was 8%, so all bulls are currently suitable to be used on heifers. That said, always consider the genetics of the heifer for calving ease when genomic tested and use assortative mating where possible.

The base population average describes the average daughter pregnancy rate (DPR) of milk-recorded animals born in 2015. Actual pregnancy rates of specific animals will differ and fluctuate around this 30% average, as will herd averages, as herds include animals of multiple ages and not all herds are milk recorded. 

There is no U.S. or global standard for motility rates of frozen bovine semen for export. However, U.S. A.I. companies have their own internal standards to ensure their product is fertile for customers worldwide. These standards include motility and other factors. Most important is the number of live motile sperm in a unit of semen, compared to a given motility rate or concentration.

There is no U.S. or global standard for motility rates of frozen bovine semen for export. However, U.S. A.I. companies have their own internal standards to ensure their product is fertile for customers worldwide. These standards include motility and other factors. Most important is the number of live motile sperm in a unit of semen, compared to a given motility rate or concentration.

No. Most important is the number of live motile sperm that are in a unit of semen, which is a factor of concentration and motility rate. The number of sperm does not differ between the 0.25mL and the 0.5mL straws. It is known that sperm survive the freezing process better in a 0.25mL straw. So, there can be a slight advantage for post-thaw motility for 0.25mL straws. Conversely, the smaller straws can be more difficult for A.I. technicians to handle, especially in challenging environments. Thus, one cannot state that 0.25mL straws are more fertile than 0.5mL straws. 

Inbreeding levels have been increasing over the past few decades. While this is a situation that must be monitored, there have not been signs of significant inbreeding depression. In essence, inbreeding has the same biological consequence as selection which is an increase of homozygosity. The homozygosity by selection is more target than that by inbreeding. Geneticists around the world, including in the U.S., are working hard to answer the question of how we maintain the same rate of genetic progress without concern for potential future consequences of higher inbreeding. In the meantime, the CDCB and USDA are actively monitoring any potential new genetic defects that may affect our cattle population.

There are criteria that bulls must meet to receive an evaluation for Sire Conception Rate (SCR). Ayrshire, Brown Swiss and Guernsey sires must have ≥200 total recorded breedings across ≥5 herds of which ≥30 breedings were from the past 12 months. Holstein sires must have ≥300 total recorded breedings across ≥10 herds with at least 100 breedings during the past 12 months. Jersey bulls must have ≥200 total recorded breedings across ≥10 herds with at least 100 breedings during the past 12 months. Milking Shorthorn sires must have ≥100 total recorded breedings across a minimum of 5 herds with at least 10 breedings during the last 12 months.

Of the primary Western breeds, the Guernsey cow has the highest frequency of the beta casein A2 gene. Approximately 98% of cows carry at least one copy, with about 80% being fully A2A2. Increased selection for the gene in the United States also promises to increase these numbers in coming years.

There are currently no detected harmful genetic recessives or haplotypes in the Guernsey breed, a fact often used to promote the breed. This was reexamined and confirmed in the Guernsey Genomic Project that brought genomic testing capability to Guernsey breeders.

The United States has the largest Guernsey population by a significant margin, with the next largest registered populations in Australia, the United Kingdom, Canada, South Africa and New Zealand – as well as the Isle of Guernsey. The Guernsey breed is growing in Asian countries such as Thailand and Japan, South American countries such as Brazil, and African countries such as Kenya and Uganda. Learn more about Guernseys around the globe at The World Guernsey Federation.

U.S. Brown Swiss male and female animals are ranked on Progressive Performance Ranking (PPR). The formula has weights which add to 100 and, thus, are comparable to the percentage weight for each variable. Progressive Performance Ranking (PPR) has been revised effective Dec 2020. Protein, Fat, Productive Life, (PL), Udder Composite, (UDC) Mobility, (MO) Daughter Pregnancy Rate, (DPR) Livability, (LIV) and Somatic Cell Score, (SCS).

The European federation with the full support of all the European National associations funded and managed a project developed with Interbull, named Intergenomics with the objective of an international collaboration for a genomic evaluation of the Brown Swiss Breed. Since August 2011, the project provides members with an up to date genomic evaluations of sires based on a joint analysis of all the genotypes collected around Europe, Canada and the USA. The international database of genotypes for the Brown Swiss populations are managed at the Interbull Centre.

Although there are many dairy breeds represented in the US, we do have 6 or 7 main breeds which are: Holstein (and Red Holstein), Jersey, Brown Swiss, Ayrshire, Guernsey and the Milking Shorthorn. These breeds have their own base for the genetic and genomic evaluation. Any animal of a different dairy breed that receives a genetic or genomic evaluation will have the values presented on the base of most closely related main breed.