She is beauty. She is grace. She is the world’s perfect cow. After years of intense selection, the Holstein cow has been transformed into the most sought-after dairy cow in the world as she excels in the three dairy trait categories of production, health and fitness, and conformation. However, one genetic trait that dairy producers have overlooked in their quest to make this perfect cow is the polled gene. In this article, we hope to tackle the question of why this matters by explaining the polled gene and its benefits to your operation. Today, there is more chatter about polled animals than ever before. Here’s why:
- No one in the dairy industry has been against polled cattle. In fact, dehorning is a task most producers dread because it takes people’s time, costs money and can be challenging. Polled cattle present an opportunity to remove unwanted tasks, reduce cost per calf and improve operational efficiency.
- We could attribute the chatter to the explosive use of beef in dairies. Beef breeders around the world have benefited greatly from the trait. With more beef cross animals created with Angus sires or homozygous polled composites and retained ownership, dairies see more naturally polled animals than before.
- Supply chain stakeholders continue to look for ways to improve sustainability and animal welfare, and polled animals are a natural fit for this discussion.
Globally, some producers are being asked by their government, milk processors and even national associations to include polled genetics in their breeding plans. Because of this interest, genetics companies worldwide have begun to focus more on polled in their genetic selection. Thus, a great deal of genetic progress has already been made in this space, providing producers more opportunities to easily include it without sacrificing progress.
The dominant gene
Most do not realize the polled gene is dominant. In simple terms, animals with one copy of the polled gene and one copy of the horned gene will not have horns. A heterozygous polled (single P) sire has one copy of the polled gene and does not have horns. A homozygous polled (double P) sire has both copies of the polled gene and does not have horns.
Using a single P sire in your breeding plan will result in 50% of the calves born being polled, depending on their mate. As for a homozygous polled sire, all offspring from a double P sire will be born without horns. This means you can create a naturally hornless animal in one generation. Because the polled gene is dominant, this allows us to create polled animals faster than if the gene were recessive. Figure 1 demonstrates the breeding outcomes of using homozygous or heterozygous polled bulls.
The benefits of polled cattle
Now that you understand the polled gene, let’s dive into a few of the benefits of a polled herd.
- Allows for immediate change: We know that the polled gene is dominant, meaning it only takes one copy to create a polled animal. Thus, we can make a polled animal immediately. Unlike most genetic selection, polled is one of the only decisions that is seen in the next generation.
- Eliminates the need to dehorn: We started off this discussion by saying no one wants to dehorn, and that’s the truth. It is a hassle, time-consuming and labor-intensive. According to the American Dairy Science Association, recent figures indicate that dehorning costs range from $6 to $25 per head, not accounting for additional expenses associated with stress and loss of growth. Eliminating dehorning promotes calf welfare, reduces management practices and increases safety for those working on dairies.
- Minimizes long-term costs and improves operational efficiency: Looking beyond just the cost of dehorning, polled cattle offer an economic solution from a labor and calf growth and management standpoint. Dehorning can be stressful, no matter how much precaution is taken. The process can result in a slowdown of growth in calves as they recover, which can impact them long term. Not to mention, the additional treatment and care a calf might receive to ensure its health affects your business’s bottom line and efficiency. Long-term, it is possible to have a dehorning miss, meaning cows with horns not completely removed, which equals a loss of time and money. Polled cattle remove the likelihood of a miss.
- Promotes sustainability: Polled naturally fits in the industry’s sustainability conversation because of its ability to promote calf welfare, reduce costs and remove the need for certain management practices. The polled gene improves the safety, efficiency and overall management of a dairy farm, directly impacting sustainability.
The quality and quantity of polled genetics
At one time, less than 1% of the Holstein population was polled, which made it hard to select genetically elite sires. However, while the frequency of polled animals has historically been low, the narrative has changed as more and more genetic companies emphasize selecting for polled. In recent years, the quality and quantity of polled genetics available in the marketplace have improved tremendously.
Genomic testing enabled the polled movement to happen. It has been a driving force in speeding up the genetic progress of the polled population, shrinking the genetic gap between horned and polled cattle. Today, the genetic value of polled Holsteins has never been higher, even rivaling that of the horned population. Heterozygous animals in the current sire population are as good genetically as horned animals.
To drive this point home, let’s look at the average net merit of currently marketed double P sires. Of the homozygous polled bulls being marketed today, the top 20 double P sires average $1,108 net merit. This begs the question, “If these sires are genetically superior and polled, why wouldn’t you use them?” Dairy producers no longer have to choose between polled or elite genetics. There is no compromise with today’s polled sires.
Recommendations for including polled sires in your genetic plan
There are two basic ways to incorporate polled into your genetic plan. With either option, we highly encourage you to work with your genetic advisor to develop the right genetic plan that meets your operational goals.
- If you aren’t ready to completely commit, introduce polled by including a few polled sires in your breeding plan. For example, in a plan with multiple sires, select one or two polled sires to replace recessive sires. Repeat this process to breed for more polled animals.
- If you want to create a fully polled herd in one generation, breed all your females to homozygous polled sires. Because of the genetic improvement in double P sires, you can create a polled herd without sacrificing production.
Similar to our beef counterparts, we could someday assume that all dairy cows are polled. Because of genetic improvement, that assumption is closer than we might think. Don’t wait until the industry shifts. The future is polled.
