Genomics – Implications for Herd Efficiency
Posted: October 15, 2013
Genetic technologies offer new opportunities to develop precise management plans that will help a farmer capitalize on the genetic merit of each animal in his or her herd. Being able to make marketing decisions based on the animal’s genetic potential for traits such as milk production, or carcass traits in beef cattle, is possible through genomics. Genomic data, in combination with more traditional evaluation methods, is another tool that producers have which helps identify genetically superior animals early in their lifespan. This information provides a higher level of certainty in estimating the value of an animal’s progeny. Producers that have not registered their animals or are not part of any DHI reporting system would also benefit from genomics as it will help deliver genetic evaluations for animals that would otherwise not have a PTA.
The evaluation of dairy records developed by USDA and breed associations has been the foundation of genetic evaluations. To this you add DHI records and powerful algorithms to generate Predicted Transmitting Abilities (PTAs) which help rank animals on various traits. The number of progeny a specific animal had would help increase its reliability for PTAs; because of this the majority of genetic progress in dairy herds in the US and worldwide has been driven by bull selection. This enabled one bull to be used as the sire of thousands of offspring, helping the industry learn about the impact of sires and their ability to transmit genes to their offspring. On the cow side, the commercial dairy cow typically has only a few offspring and production records throughout her life. With genomics there is an opportunity to progress at a faster rate within the female population.
After years of research, scientists sequenced the bovine genome, which has approximately 3 billion base pairs, identifying which markers impact directly her physical appearance and production performance, genes of greatest importance to the dairy producer. The overall genetic influence on the phenotype is the sum of the effects of different genes dispersed throughout the animal’s DNA. For many of the traits, there are hundreds of genes that are involved and in addition to that environment has a major role to play. Genotyping helps identify which genes an animal has inherited, giving an indication of what might be transmitted to its offspring. The results are reported as Genomic Predicted Transmitting Abilities (GPTAs) and are presented in the same way as traditional genetic evaluations.
How Does This Affect You?
Identifying animals with superior traits for longevity, health, and performance are key to farm profitability and continued growth. One important index offered is Net Merit (NM$), which predicts the expected lifetime profit contribution of an individual animal compared with the breed base. It includes economically relevant traits with weights of 48% for health and fitness traits, 35% for production, and 17% for conformation. Genomically testing a group of heifers will not only help identify elite animals, but also identify animals with lower genetic potential.
Managing herd inventory regularly helps contain costs, and in extreme situations, such as extensive drought, the ability to selectively cull inferior animals is very important for beef and dairy producers. Investing in genetically superior animals and selecting for relevant traits will help manage feed costs and at the same time assure genetic progress. This technology provides producers with the flexibility of testing early in an animal’s life so they can be more confident in their decision making. It is important to apply a long term herd strategy and maximize the value of the investment. Paying for the information and not using it is an inefficient strategy.
Before Getting Started
As with any new investment and application of new technology in your farm, there are various questions that have to be answered beforehand. Implementing technologies like genomics may affect your current business model and marketing opportunities, which is one reason why it’s important to think long-term. Not only do you have to decide what animals in the herd should be tested but also consider goals, herd inventory, selection decisions, feed costs and at the same time take into consideration the price fluctuation of milk and meat. Understanding the goals of your herd now and in the future and knowing your return on investment (ROI) is imperative.
Technology will continue to move the dairy industry and will play a large role in the progression and succession of a dairy.
To help you keep up with all this new technology, the Penn State Extension Dairy Team has developed a Dairy Reproduction Certification class that will cover topics in reproductive efficiency. Also this fall there will be two Precision Dairy Technology Forums to inform farm managers on precision dairy technologies, strategies to implement these technologies and factors to consider when taking the leap into these technologies on their farms. The first forum will be held in Chambersburg on October 18 and will focus on robotic milking and automatic calf feeding. The second forum will be held in Lancaster on October 31, and the focus of this program will be genomics and activity monitors.
Additional information can be found at http://extension.psu.edu/animals/dairy/events.