When breeding for long-lasting dairy cows, many producers do not feel they have all the tools, indexes and traits to help guide them to reach their goals. Surprisingly, the information and indexes that are most important for breeding longevity and efficiency into their herds have been available for quite some time.
This information can be broke down into three main areas: production information, type or conformation indexes and health traits.
Production
Overall production – especially fat and protein pounds – remain an important factor when choosing genetics and making culling decisions.
Milk still has value, but for most producers, component pricing has made fat and protein more important. In order for a cow to stay in the herd, she must “pay her way.”
This is especially true today with high cull prices and even higher feed costs. If she’s not profitable, longevity or reproductive efficiency will not matter. Voluntary culling will remove her.
Conformation
A conformation trait that plays a major role in longevity is body size and stature. Parlors and freestalls are built for average-sized cows. An oversized cow has more trouble maneuvering in and out of the parlor and freestall and is more prone to injury.
The large cow also tends to have more foot and leg issues, especially on concrete. In addition, the large cow must consume more feed just to maintain bodyweight compared to a moderate-sized dairy animal.
Udder traits are another indicator of overall functionality of the dairy cow and play a large role in the longevity of a cow.
Udder composite is an important selection tool when choosing sires. Specifically the traits of udder depth, cleft and attachment are the keys to maintaining udder quality.
Foot and leg composite and the traits used to calculate it are also important when building a long-lasting cow.
Foot angle is especially important for cows that spend most of their lives on concrete. Leg set is an example of a trait that breeding for the middle – neither too posty or too sickle – is best for longevity.
Health traits
Daughter pregnancy rate is one of the most important of the health traits when breeding for longevity. The easier she is to breed back, the more lactations she will have in her lifetime and more peak lactation periods.
A cow is most profitable to the producer when at peak production – shorter lactations, more peaks, more income.
Somatic cell score is another important health trait. Somatic cell score is the best tool we currently have to select for mastitis resistance, an obvious reason cows leave the herd.
In addition, reducing somatic cell counts can increase profits through quality bonuses. This is an area where more research is needed and is being done. A true mastitis resistance index would be of great value.
Productive life is the overall health trait index. Productive life can be a very important selection tool. However, this number may become somewhat less valuable, especially during our current dairy economy.
With the excess of replacement heifers, low milk prices, high feed costs and cull prices, along with production caps in many regions, cows are leaving herds much sooner than in the past. High cull rates and herd liquidations may have an effect on productive life.
For now, the best overall indexes for breeding long-lasting cows are net merit or cheese merit, depending on your milk market. These indexes calculate in all the factors discussed here and do a good job of ranking bulls accordingly. Are they perfect? No. Are they a work in progress? Yes.
Would more and better information be beneficial? Absolutely, but for now they do a very good job of sorting bulls. The producer can then make decisions from there on the individual traits they feel are most important to their operation.
In the future, more and better traits will be available to help make breeding decisions which may make things more complicated but will allow us to breed a longer-lasting, better generation of cows. PD
Scott Bennett
Territory Development Specialist
CRV
