Eric Sonnek
County Technical Advisor, St. Cloud
December 11, 2004

One of the most exciting places to be on a dairy operation is in the fresh cow pen. This is where we see calves being born. Especially on the larger dairies, this can be a continuous sight every day. I enjoy this area of the dairy operation because this is where you first see future generations of cows that hopefully will keep the dairy operation productive and profitable for years to come. Approximately nine to ten months before that calf was born, an important decision was made. The question: “to what bull should that cow or heifer be bred?” That decision has a long-lasting impact on the future of the dairy herd.

The November Bull Proofs have recently been completed and many of the bull semen companies are promoting their different bulls. To help sort through this information, let’s walk through some of the decisions that are made for breeding programs on dairy farms.

• The first decision that needs to be made is whether to use a natural service sire or artificial insemination. Some producers feel that it is cheaper, easier and simpler to have a bull available for the dairy herd than using artificial insemination. However, before the claim can be made that bulls are cheaper, we must remember that bulls also cost money and they have a labor cost too. There is the initial cost to purchase the bull. Then there is the expense to feed and house it. There is also the risk, if by chance, of purchasing a bull that cannot get cows pregnant. Then dollars are being lost every day cows are open. Bulls also can transmit diseases that can be devastating to the herd, and affect the dairy producer’s profitability. Yes, it does cost money to purchase semen and have someone breed the cows, but it costs much more money to keep a poor-performing bull in the herd.
• Bulls that are available through AI are more valuable than non-AI bulls. According to research, a daughter of an AI bull generates about $148 more net income per year than daughters of natural service bulls. This number may seem somewhat insignificant but if there are 100 cows in the herd, this is $14,800 more income than if natural service bulls were used.
• Is utilizing a bull easier and more successful than going with AI? Many reproductive management programs exist today that make breeding cows and catching cows in heat simpler. Synchronization programs and using CIDR implants are examples of these tools.
• No matter what the concerns about ease and simplicity, safety issues always exist when managing and housing a bull on the farm. Unfortunately, each year there is the news of someone being killed or severely injured by a bull. The dairy family really needs to determine if having a bull on the farm is worth the risk.
• If and when it is decided to utilize AI, then the decision needs to be made as to what genetic traits are important to the profitability of the dairy herd. Bull proofs have many, many traits for which each bull is evaluated. There is everything from teat length to stature and even to somatic cell score included in genetic evaluations. The dairy producer must know and understand the farm’s breeding goals and what is important to the future of the herd. If only one trait is chosen, such as Udder Depth, then important improvement will most likely be made in udder depth but the producer will probably lose ground on other traits, such as milk production.
• An easier and better way to go is to use an index. An index combines many different traits into one number with weightings on each for importance in order to come up with a value for each bull. Each dairy breed has its own genetic base. Lifetime Net Merit Dollars (LNM$) and the Holstein USA’s Type-Production Index (TPI) are just a couple of examples. When choosing which index to use, the dairy producer should look at what all is included in the index and then determine if it matches the producer’s goals. In general, LNM$ puts more emphasis on health traits whereas TPI places more emphasis on the production and the way a cow looks.

The following chart shows two examples of different traits used in genetic indexes–Lifetime Net Merit Dollars and Holstein USA ’s Type-Production Index.

Dairy producers need to stay current with indexes as they change over time. Periodically look them over, and then make sure they are meeting or matching the farm’s breeding goals. New genetic bases are introduced for all traits every 5 years. The next base change will be done in 2005. The genetic base is determined from the average of cows born in a specific year. In 2005 the base will be set by the average of cows born in 2000.

With today’s genetic information and breeding technology, indexes and synchronization programs make breeding cows easier and less time consuming. It makes having a bull on the farm to solve breeding problems less appealing. When combined with good conception rates, the result can be greater genetic improvement for the dairy herd and more satisfaction from those months of waiting for some exciting births in the calving area.

For further information on genetic evaluation and the opportunity to create a customized list of bulls that meets the user’s criteria, visit the U of M Dairy Extension web site at www.extension.umn.edu/dairy. Click “Reproduction/Genetics” on the left column. Then check out these three links: USDA’s Animal Improvement Programs Laboratory; National Association of Animal Breeders (NAAB); Global Dairy Sire Genetic Evaluations.