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Predict future milk production using average daily gain

Chrissy Meyer for Progressive Dairyman Published on 28 February 2017

From the perspective of an A.I. company, the strategic breeding and genetic decisions you make today have a huge impact on the profitability and bottom line of your future milking herd.

However, it’s important to remember that the only way to realize the maximum benefits and effects of the genetics you use is to maintain top-notch, progressive, strategic management practices.



Genomic testing has claimed its spot as a popular method for ranking heifers as part of a strategic breeding plan. Yet if you’re looking for ways to not only maximize genetic progress but also future profit, there might be alternative methods to decide which heifers to cull and which to keep.

Average daily gain as a female selection tool?

References to average daily gain (ADG) typically come from the beef industry and, more recently, dairy nutritionists and researchers. Dairy-focused studies have proven that individual dairy farms can see the impact of ADG on future milk production potential.

In fact, a study from Cornell University showed that for every 1 kilogram of preweaning ADG, calves produced 1,113 kilograms more milk during their first lactation.

Weighing individual animals at set points early in life to determine their ADG can be an effective means to predict which animals will produce the most throughout their first and later lactations.

Take the example below. On this 2,850-cow Holstein farm in Wisconsin, weights are taken on each individual calf at birth and weaning, and calculated within their herd management software to figure out the ADG of each animal (Table 1).


Lactating cows

Here, we’ve broken down all first-lactation animals into quartiles based on their initial ADG. The top animals for ADG gained nearly 1 kilogram per day from birth to weaning, while the bottom 25 percent of animals for ADG gained 0.76 kilograms per day during that time.

Fast-forward two years to when these calves have entered the milking herd, and that difference in ADG equates to a real and noticeable 575-kilogram-per-animal difference in first-lactation 305-day mature equivalent milk production. This is on par with the results from the 2012 Cornell University study mentioned above.

Genetics still matter

If we take this analysis one step further, we can see that genetics are able to express themselves to a fuller advantage in healthier calves that grow more each day.

When we split the groups from the same analysis shown above in Table 1 to do two separate genetic assessments, we can see how animals in each group perform in relation to their genetic predictions. This shows us whether ADG affects whether an animal can produce to their genetic potential.

Table 2 takes only the first-lactation cows that were among the top 25 percent of heifers for highest birth to weaning ADG.


Highest ADG animals

Within this high-ADG group of animals, we compare 305 mature equivalent milk production based on parent average for PTA Milk within that group.

Here, it shows that among only the calves with the highest ADG, those animals with the higher parent average for PTA Milk calved in to produce 1,260 kilograms more milk than the animals with a lower parent average for PTA Milk.

Table 3 looks at this the same way but only splits out the first-lactation cows that were in the bottom 25 percent for lowest birth to weaning ADG.

Lowest ADG animalsWhen we compare milk production within that isolated low-ADG group, we see that a higher parent average for PTA Milk equated to just over 800 additional kilograms of milk in the first lactation compared to the animals with the lowest parent averages for PTA Milk.

Within both groups of animals, a higher parent average for PTA Milk meant even more milk than predicted by genetics. However, when you compare the difference in first-lactation 305 mature equivalents, you can see that the high-ADG group outpaces the low-ADG group by nearly an additional 440 kilograms of milk in the first lactation.

This means that when calves are given the best nutrition and care, and achieve higher ADG, their genetics are better able to express themselves beyond what’s even predicted.

Strategic management decisions

With this proof in mind, if your farm’s situation dictates culling extra heifers, it’s best to do that in a strategic way. While genomic testing certainly has its merits for this purpose, the power of monitoring and measuring ADG can serve as an effective alternative.

If the animals that perform well early in life go on to perform better than herdmates later in life, it’s an easy decision to keep the fastest-growing animals in your herd.

If you cull those calves that perform at a sub-par level from the start, you can avoid the feed costs for animals that will produce less than herdmates in the future and avoid housing animals you may not have room for on your farm.

Knowing that those healthy calves will put extra kilograms in the tank down the road also enforces the power of proper and progressive calf nutrition and a sharp focus on overall calf health. Even when times are tight, the future of your milking herd should not be put on the back burner.

Points to ponder

  • When implementing a strategic plan to cull heifers, consider weighing each individual calf at various milestones in her life to determine ADG. A ranking based on ADG to sort which heifers to keep and which to cull can have a big impact on overall future costs of production.

  • Don’t let the genetics you select go to waste. An animal’s genetics are expressed best when she receives the best nutrition and care from day one. The amount each calf gains per day, even in those first few months, will make a major impact on future production potential.  end mark

References omitted but are available upon request. Click here to email an editor. 

Chrissy Meyer
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