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Base growth management on average daily gain, cost per day

Gene Boomer Published on 27 April 2012

Raising quality dairy replacement heifers is not an inexpensive or simplistic endeavor. If your goal is to rear heifers that reach desired breeding parameters early so that animals begin puberty, establish a pregnancy and calve easily and on time, you must be aggressive in your heifer management program.

Plus, you must accomplish these objectives at a reasonable cost. Feed cost is generally the largest expense for raising replacement heifers, and margins require that dairies be prudent when managing heifer growth and performance. However, while daily rearing cost is important, it is really only part of the picture.



Assessing a heifer’s average daily gain (ADG) and cost per pound of gain are more sensitive metrics than cost per day, and more top managers are turning to them to assess heifer program performance. When used in conjunction with health records and visual observation, this assessment offers a better means to determine which animals will bring the most potential productivity and profitability to your herd in the long run.

ADG also helps determine which heifers will not make the cut and should depart the herd before any additional investments are made. In the past, producers have kept all of their heifers and calved them into the herd.

But with high feed costs and more replacements available today than ever before, producers are realizing it’s better to know sooner rather than later which animals will be the most productive in the milking herd.

Feedlot lessons
The concept of managing for average daily gains and feed efficiency is a model that has long been used by the beef feedlot industry, which is skilled at separating feed cost from fixed costs like yardage (or housing) and labor. This perspective enables managers to increase income by increasing lean gain.

The same can be accomplished in the dairy industry by improving the quality of heifers in rearing programs. You may pay more per day for that extra 0.1 pound of gain, but you also end up with more productive animals, which improves long-term profitability.


Optimal growth is key
Neglecting proper nutrition and animal comfort during the early stages of development are sure ways to fail in meeting the goal of bringing heifers into the milking herd on time. That’s because undersized heifers are usually less productive than those of optimum size when they reach the milking herd.

Properly developed heifers partition less energy to growth and more to milk production in the first 150 days of lactation. They start their productive life sooner and peak higher with fewer transition problems.

On the other hand, overfeeding energy in relation to metabolizable protein can result in overconditioned heifers that lack stature and capacity.

The goal should be for heifers to look and perform like athletes, with strong muscle and bones and little fat.

Keep in mind the rising cost of feed means it’s more expensive to bring heifers into the milking string. By closely monitoring performance the first 70 to 120 days, you can make herd removal decisions much earlier than dairies traditionally have made.

Better nutrition the first 70 days also results in greatly reduced morbidity and mortality. This lowers veterinary costs and treatment labor significantly. Therefore, it’s important to aim for optimal growth so heifers calve in a timely fashion.


Set growth targets
To know which animals meet your goals for optimum growth, track heifers by cohort group. This enables you to account for seasonality of performance and helps fine-tune your management response to rearing challenges that arise at different times of the year.

• For the first 70 days, a reasonable ADG should be 1.7 pounds to 2 pounds per day. This will be driven by colostrum management and the feeding program, as well as weather and animal comfort.

• By 6 months old, heifers should average at least 2 pounds of gain per day.

• Your target for first breeding should be based on size rather than age. Depending on breed and individual herd dynamics, heifers should be about 51 inches at the hip (for Holsteins), about 55 percent of their dam’s mature bodyweight at breeding and about 85 percent of their dam’s mature bodyweight at calving.

• Don’t guess when it comes to determining whether a heifer is big enough to breed. If you don’t have a weight tape or hipometer handy, grab a tape measure and mark where 51 inches is in relation to the height of your headlocks or feed lane. That way, you can tell at a glance whether heifers have reached an acceptable size to enter the breeding pen.

These guidelines will help you lessen the variation between animals and develop more uniformity in heifer groups, as well as the herd. It also becomes easier to identify heifers that don’t meet these growth goals so you can make more informed grouping or herd removal decisions. PD


Dr. Gene Boomer DVM
Arm & Hammer Animal Nutrition