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M A N A G E M E N T
Managing Genetics, Considering Calf Value
When determining how to manage herd genetics, one important consideration is the value of sourcing additional replacements from our best animals and fewer (or even zero) out of our lowest genetic animals. Calf Math has been updated to help capture that value. To calculate the value of calves, one must consider the value of the calves’ sires and dams. Lifetime Net Merit (LNM) is the industry standard for lifetime profitability and is readily available for active A.I. sires. The LNM level of the female population serving as dams can be found through parent average, DHI processing center predicted LNM value or genomic test (most accurate method). Once the value of service sires and the female population are known, the estimated value of the resulting calves are simply the average. Below is an example of the updated version of Calf Math. You can see a line for the LNM value of service sires. Also included is a place for actual or predicted LNM values for each quartile of the female population. To maximize genetic gain, a dairy can establish a breeding program to get more replacements from the top female quartiles and fewer from the poor females.
Here’s How it Works
Look at the Calf Math example below again. It features two possible breeding scenarios for a 1,000-cow herd (again, concept applies to any herd size). The scenario on the left, under Base Herd Scenario, uses 100% conventional dairy semen on all genetic quartiles of cows and heifers. The
scenario on the right, under Comparative Herd Scenario, is more aggressive. In addition to conventional dairy semen, GenChoice 90 is used for 75% of the breedings to the top three quartiles of heifers. GenChoice 90 is also used for 10% of the breedings to the most elite lactating cows. The bottom quartile of lactating cows, typically the herd’s lowest genetic level animals, is bred with conventional beef semen. The boxes at the bottom of the Calf Math example show that between the scenarios the total number of projected replacements yielded is comparable. However, the LNM of the resulting offspring is very different. This is explained because the aggressive scenario yields 54 additional heifers out of the highest genetic merit heifers and 56 fewer from the lowest genetic merit cows. This creates a $36 per heifer genetic advantage over the scenario on the left. Multiplied across the entire herd that dollar difference can mean huge dividends once these offspring enter the milking string. The aggressive scenario essentially eliminates the more unprofitable genetics (bottom quartile of cows) from the herd’s future gene pool. Instead those animals contribute to additional revenue through production of beef x dairy calves. From the various scenarios on pages 21 and 22, it is obvious Calf Math is a tool enabling producers to consider new breeding strategies. Calf Math creates an opportunity to consider current and future local economic conditions and see how different breeding strategies could position the dairy for success. Calf Math makes it clear: there are more choices to make in managing a herd’s genetics than ever before.
A Author Bio: Dustin Hollermann graduated from the University of Minnesota with a degree in animal industries management and an emphasis in dairy science. He possesses a real-world understanding of applied dairy genetics and reproduction physiology along with an unparalleled talent for combining computer programming and genetics. Dustin has 10+ years of experience in the dairy genetics and A.I. industry.
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