Friday, July 20, 2018

DNA Evaluation

Last week, we analyzed weaning weights on the LiveWiRED project calves. Upon evaluating these weights, we found a positive relationship between Weaning Weight EPD of the sire and the performance of their calves (calves by sires with higher Weaning Weight EPDs weaned heavier). As yet another part of this project, DNA samples were collected on the calves, and both GeneSeek Igenity Gold and Zoetis PredicGen DNA tests were conducted. Every animal in the project was evaluated with these two different DNA tests.

Ribeye Area. As more traits and DNA scores were evaluated, the general trend of EPDs proving accurate continued. Calves by the three high-growth/high-carcass sires averaged a score of 5.42 for Igenity ribeye area (REA) on a 1-10 scale, with 10 being the highest achievable score and indicating genetics capable of producing a larger ribeye. Progeny by the two low-growth sires averaged a lower REA score of 4.0. While performing appropriate statistical comparisons, an impressive p-value of 0.00001 was found (p<0.01). This result allows us to be over 99 percent confident in saying there is a significant and measurable difference in ribeye area DNA scores between the high-growth/high-carcass sired calves versus low-growth/low-carcass sired calves. This difference is very visible in the graph noted below. These genetic differences will undoubtedly show up in our final carcass results when the cattle are harvested.

Marbling. Moving on to the trait of marbling, the Zoetis PredicGen DNA test also shows impressive Marbling DNA score differentiation between the sire groups. After performing basic statistical analysis on the data, a p-value of 0.0025 (p<0.01) was found. This once again, allows us to be over 99 percent confident that a real difference exists between the calves by the high-growth/high-carcass sires versus those by the low-growth sires in terms of Marbling scores from this DNA test. See details in the chart below.

The value of DNA testing in the LiveWiRED project is their unbiased evaluation on the expected performance of the progeny. DNA results provide positive reassurance that the EPDs are correctly measuring the performance of the sires and their progeny. The two DNA test results discussed above are great examples of how EPDs can be both verified and improved through genomic testing. There’s no question that EPDs are being made more accurate by the incorporation of DNA technology. This process aids ranchers in making more effective bull purchasing and mating decisions to more effectively achieve herd improvement, the ultimate goal of the Red Angus breed and the beef industry.

Thank you to the Red Angus Foundation Inc. for sponsoring the LiveWiRED Project!

Wednesday, July 18, 2018

Weaning Weight Data and Project Update

The LiveWiRED project is nearly two and a half years into action. Forty-two calves have been weaned and are being backgrounded in Missouri with plans for shipment to a Kansas feedlot in early August. With newly collected weaning weight data, the project is one step closer to unveiling the power of EPDs for the genetic improvement of the Red Angus breed as well as the beef industry as a whole.

About the Project
The initial design of the LiveWiRED project was to evaluate the actual performance of sires compared to what their EPDs predict. In order to obtain an accurate assessment of the sires, a Gelbvieh cow named Penny was used as the sole donor cow for the entirety of the project. By utilizing a single donor cow as the dam of all the LiveWiRED calves, we can isolate sire-side genetics and obtain results that accurately portray the performance of multiple Red Angus sires compared to what their EPDs predicted.

Penny was flushed to five different bulls to produce calves for this project. Three of these Red Angus bulls rank high in the breed for growth and carcass traits and are referred to here as “high-growth sires.” The other two bulls rank poorly in the breed for growth and carcass traits and are referred to as “low-growth sires.” Throughout the duration of the project, the two sire groups will be compared in various ways, and, in some cases, calves by individual sires will also be compared to determine if observed performance differences match those predicted by the sires’ EPDs.

Project Update—Weaning Weights
Taking a look at the entire calf crop, the heaviest weaned calf stepped on the scale at 486 pounds while the lightest calf came in at 351 pounds. The average weaning weight was only 421 pounds after the 205-day adjustment. With weaning weights being significantly lighter than expected for all progeny, there is little doubt that non-genetic factors caused reduced growth rates. Sub-par nutrition took a toll on the calves and they were also affected by drought, which has been a problem in the area where the calves were raised.

When evaluating bulls and heifer calves in the Red Angus breed overall, the average weight difference among fall-born calves is 42 pounds, with bulls being heavier. The LiveWiRED calves showed only a 19-pound difference in 205-day weights between the sexes (less than half the normal weight difference). Nutritional/environmental limitations undoubtedly created the lack of spread between the heifers and bulls across all calves in the project, and also limited the growth expression of the high-growth versus low-growth sired calves. Weight differences between the bulls and heifers were ‘compressed’ by environmental factors, so it is understandable that the sires’ Weaning Weight EPDs were not fully expressed either.

For the purpose of this discussion and analysis, all calves were adjusted to a 205-day weaning weight and all heifers were adjusted up 19 pounds to account for observed sex differences. Sire EPDs are the main factor being evaluated in the project, since all calves have the same dam. One sire in the high-growth group, Sire A, sired 16 calves. Six of these calves ranked in the top 10 for heaviest weaning weight among all project calves. The adjusted 205-day weights for high-growth Sire A were then compared with the weights from low-growth Sire B, who sired 11 calves in a simple statistical test.  Sire A and Sire B were the top two sires in progeny count, so it made sense to directly compare their progeny.

The data showed that high-growth sire A calves weighed, on average, 22.6 pounds more than low-growth sire B’s calves. The actual difference in Weaning Weight EPD between these two sires is 40 pounds, so only a little over half of this genetic difference was actually expressed due to the aforementioned non-genetic limitations. Even so, our p-value was 0.04 (p<0.05) in this analysis, therefore, we can be more than 95 percent confident that a statistically significant difference in weaning weight occurred between the two sire groups. The graph below provides a good visual of this data, illustrating the cause-effect result between Weaning Weight EPDs and actual weaning weights.

The weaning weight data is giving us a great start in comparing Red Angus sire performance. As these calves continue to grow and perform, as well as change environments during their transition to the feedlot, a greater spread in weights between high- and low-growth sires is expected. Even with the smaller weaning weight spread, we can still clearly see a positive correlation between higher weaning weight EPDs and heavier actual weaning weights, which is the ultimate goal of the LiveWiRED project.

Thank you to the Red Angus Foundation Inc. for sponsoring the LiveWiRED project!

Tuesday, March 6, 2018

It's All in the Genes!

The power of DNA technology is limitless in the beef industry! Producers have the capability to unlock incredibly valuable knowledge corresponding to their livestock that allows them to make more informed mating and culling decisions. One of these great tools is the RA50K. The RA50K is a tool that analyzes over 50,000 locations on an animal’s genome. The data collected is then incorporated into the animal’s EPDs. These EPDs then become much more accurate, especially when the RA50K is performed on unproven animals such as virgin bulls or heifers. The main benefit of utilizing the RA50K technology is the improved accuracy. Accuracy is a measure of how correct EPD information will accurately portray an animal’s true genetic merit. This value ranges from 0 to 99, with 99 being the most accurate. These accuracies can be improved not only with the RA50K, but also performance data such as birth, weaning, and yearling weights, as well as stayability and carcass traits. The accuracy improvements can be shown in the diagram below provided by the RAAA’s Rancher’s Guide to 50K article. Another benefit of the RA50K is the parentage verification. While most often the sire can be predicted if AI technology or single-sire breeding groups are used, sometimes the bull jumps the fence or a cow gets sorted incorrectly when heading to pasture. This parentage verification helps decrease the parentage error within the database that sometimes happens due to these mistakes. This leads to more accurate data for all to utilize. The RA50K is only one of many different genomic tools used in the Red Angus breed. Producers have the option to utilize high-density, low-density, and ultra-low-density genomic panels through GeneSeek as well as the i50K test through Zoetis. These DNA samples can be collected through blood, hair, semen, or tissue samples and are the first step to accessing a wealth of knowledge that not only will improve the quality of your herd, but the Red Angus breed and beef industry as a whole through improved genetic accuracy.

Monday, February 26, 2018

Winter Nutrition

With cold and windy conditions outside, it is very important to makes sure your cattle have the right nutrition and shelter. This can look a lot different depending on where you live and what the conditions are like. However, the LiveWiRED calves are in Lathrop, Missouri. In Lathrop, they can have severe cold temperatures, dangerous wind chills and snow, which can be extremely hard on cattle if they are not treated right.
When it gets cold cattle naturally increase their body heat production, by increasing there heart rate, respiration and blood flow. They also eat more to get more energy. Cattle prepare for cold temperatures months before, by growing longer hair and changing their metabolism. This is what the cattle do during the cold months and before, but it is also very important that we provide a place that is dry and out of the wind and the right feed.
When the temperature is 17 degrees Fahrenheit outside, a cow that has a dry winter hair coat need about 15% more energy. While a cow with a completely wet or matted down with mud hair coat needs 40% more energy than in moderate conditions. This makes a big difference, in the amount of feed needed. So it is important to have a place that is dry and out of the wind. This could be a shed or a windbreak that protects the cows from the wind. It is also important to have bedding. It helps keep the cattle clean and gives insulation from the snow and frozen ground.
During cold and windy conditions it is very important to feed the right nutrition to your animals. This includes providing all the hay they will clean up, silage, grain, protein supplements, and mineral mixes. If calving in the winter or spring it is crucial to give adequate protein 60 days before giving birth. This is for the development of the unborn calf and colostrum formation. Winter conditions can be very hard on cattle, but with the right nutrition and shelter, it can make it a lot easier.