U.S. dairy genetic evaluations are released weekly, monthly and triannually – dependent on animal status. The triannual evaluations for 2022 are April 5, August 6 and December 6. The 2023 triannual evaluations are April 4, August 8 and December 5.
The United States expresses the actual predicted value that a bull, cow or heifer transmits to its offspring, which is 50% of the animal’s own genetic merit. The other half comes from the opposite parent, which is unknown until revealed.
Lifetime Net Merit Dollars ($) is the U.S. national selection index that combines information on about 40 traits, including yield, conformation, health and fitness, feed efficiency and fertility. Composite selection indices are valuable tools in modern dairy cattle breeding because they enable information from many traits to be combined into a single value for ranking animals, thus simplifying selection decisions.
CDCB publishes 4 lifetime merit indices that are similarly expressed but differ in the emphases assigned to individual traits. Net Merit fits the milk market and management system for many U.S. dairy herds. Cheese Merit and Fluid Merit estimate profit potential in specific milk markets, while Grazing Merit fits seasonal calving and grazing operations.
Indices are valuable tools in cattle breeding because they combine many traits into a single value that drives genetic progress, ranks animals and streamlines management decisions. Selection indices are weighted, which means that an appropriate emphasis is placed on specific traits relative to breeding goals.Net Merit, for example, accounts for more than 40 traits – including production yield, conformation, health and fitness, fertility and feed intake.Selection indices provide a more balanced way of selection. Individual trait cut-offs can result in an animal being rejected based on just one or a few traits – eliminating the opportunity to take advantage of other traits that may be highly beneficial and more important to the breeding objective. Greater profit is always delivered with composite indices rather than when independent culling levels are used.
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.
CDCB introduced Feed Saved (FSAV) in December 2020. 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. Feed Saved is measured in pounds of dry matter intake. Larger, positive values are more favorable. Predicted Transmitting Abilities (PTAs) for Feed Saved are provided for Holstein males and females.
Residual Feed Intake (RFI) is a measure of feed efficiency and is defined as the difference between an animal’s actual feed intake and its expected feed intake based on its size and growth compared to the breed average base. RFI is independent of the level of production. The lower the RFI value, the more efficient the animal is.RFI was incorporated into the CDCB lifetime merit indices in August 2021.
The United States has made great 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 U.S. Holsteins is 2.2% with a max of 5 to 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.
That depends. If the bull is not an A.I. bull, then the costs would only be the nomination fees at CDCB.
If semen is collected and the bull is marketed on values from the U.S. genomic evaluation, the bull is subject to fees from CDCB and National Association of animal Breeders (NAAB).
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.
Genomic testing of dairy animals is offered from a variety of organizations, including breed associations, genetic providers and genotyping labs. The price for a genomic test generally ranges from $20 to $50 (US$). Testing at a higher density may come at a higher price.
All A.I. bulls enrolled in thedairy cross reference database managed by National Association of Animal Breeders (NAAB) have a bull status code. This code represents the activity status of the bull. Bulls with the A (Active), F (Foreign) or G (Genomic) code are actively being collected and marketed, so they will appear on industry ranking lists in CDCB WebConnect and from other sources.
Although there are many dairy breeds represented in the U.S., the main breeds are Holstein (and Red Holstein), Jersey, Brown Swiss, Ayrshire, Guernsey and Milking Shorthorn. These breeds have their own base for genetic and genomic evaluation. Any animal of a different dairy breed that receives a genetic or genomic evaluation will generally have the values presented on the base of the most closely related main breed.
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 serious inbreeding depression. In essence, inbreeding has the same biological consequence as selection which is an increase of homozygosity. The homozygosity by selection is more targeted 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.
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 dairy genetics – 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.