Feed Large Part of Cost of Raising Heifers

By Ron Johnson, Dairy Editor
Monday, November 20, 2006 6:04 PM CST

About two-thirds of the cost of raising a dairy replacement heifer comes from feed.

There are ways to raise heifers less expensively and still have them milk well later.

Pat Hoffman, a UW-Madison dairy scientist, talked about ways to boost heifer feed efficiency during last week's Midwest Dairy Herd Health Conference at Stevens Point.

He pointed out that the philosophy of feeding replacement heifers is different from that for feeding lactating cows. In general, dairy producers feed lactating dairy cows highly fortified rations to make sure that they get enough nutrients to produce the amount of milk they are capable of.

Heifers, by contrast, should be fed so that the nutrients are tightly controlled, Hoffman compared. But doing that can require lots of attention to long-term strategies.

Nutrient requirements

To give heifers the right nutrition, you have to know what they need. So just how much feed do heifers need?

A 300-pound, large-breed heifer that's gaining 1.8 pounds a day needs to eat 9.3 pounds of dry matter. That assumes she's in an environment where she doesn't have to produce much - if any - body heat. Such an environment has an air temperature of 50 to 70 degrees.

That 300-pound heifer needs to eat enough crude protein to make up 16.9 percent of the dry matter she eats, the dairy scientist explained. Rumen-undegraded protein should make up 39.4 percent of the total protein she eats, with the remaining 60.6 percent as rumen-undegraded protein.

By contrast, a large-breed dairy heifer weighing 600 pounds needs to eat 13.7 pounds of dry matter if she is to gain 1.8 pounds a day. The crude protein in her ration should be 15 percent of the dry matter, with 33.8 percent of it as rumen-undegraded protein and 66.2 percent as rumen-degraded protein.

At 900 pounds, a heifer needs to eat 19.4 pounds of dry matter a day, and it should provide 14.2 percent protein. Here, 30.3 percent of the protein as rumen-undegraded protein and 69.7 percent as rumen-degraded protein is ideal.

The amount of dry matter needed keeps rising, and the amount of protein needed keeps falling the heavier a heifer grows. At 1,200 pounds she needs to eat 26.9 pounds of dry matter, but only 13.3 percent protein. At this weight, 26.3 percent of the protein should be rumen-undegraded, while 73.7 percent should be rumen-degraded, according to Hoffman.

Vitamin and mineral needs also change as a heifer grows. One at 300 pounds needs calcium as 0.45 percent of her daily dry matter intake, while a heifer weighing 1,200 pounds needs only 0.36 percent calcium.

Environment

Because Wisconsin's weather is often colder than 50 degrees and warmer than 70, a heifer's ration needs to change with the changing conditions. Hoffman reminded that heifers need more energy when the temperature is under 50 degrees, when they are in wet conditions, when their coats are dirty, when they're kept in cold and uninsulated areas, when they're exposed to wind, and when they're not getting much sunshine.

The lighter the heifer, the less able she is to handle less-than-ideal conditions. One that weighs 300 pounds has a tougher time than a heifer that weighs 1,000 pounds.

As heifers gain weight and rumen capacity, they're much better equipped to handle cold, wet conditions, explained Hoffman. In most situations young heifers need a good environment and perfect resting areas rather more energy to overcome poor conditions, he added.

Overconditioning

While it's important to feed heifers so they gain well and are healthy, it's also important to make sure they don't become overconditioned - fat. That's because fat heifers are more prone to problems.

At calving, for example, fat heifers are more likely to have trouble, and they're more likely to develop metabolic diseases. Dietary protein plays a minor role in heifer condition, while overfeeding energy is the biggest culprit, Hoffman said.

If heifers do become overconditioned, cut back on their energy intake, he advised. Do that by changing their ration to include a low-energy forage, such as straw. In addition, limit the amount of feed offered.

Heifers' protein and energy needs change over time and with conditions. The younger a heifer is, and the faster she grows, the more protein she needs.

Feeding excess protein will keep a heifer from getting overconditioned, Hoffman reminded. Neither will extra protein make her taller. When heifers eat more protein than they need, the excess is simply excreted as nitrogen in their urine.

Vitamins, minerals

It's common to feed dairy heifers too much in the way of vitamins and minerals, too. That, of course, raises costs. Hoffman recommended having forages and other feeds tested for their mineral content.

And, if possible, avoid letting heifers have free-choice minerals and vitamins. Specifically, heifer raisers should be sure to feed precise levels of dietary phosphorus, the dairy scientist emphasized, because feeding them too much phosphorus puts excess amounts in their manure.

Waste

Feed wasted is also money wasted, Hoffman reminded. Feedbunks can be designed and managed to lessen feed waste.

Properly adjusting neck rails and throat heights, or installing slant bars in the feed alley can often cut feed wastage dramatically, he said. Hoffman advised against using hay racks, portable bunkers or other make-do feeders, since too much feed can be lost on the ground.

Bunk management

It's a good idea to monitor the amount of feed dairy heifers get. Hoffman talked about a bunk scoring system that can help growers decide whether they're feeding heifers too much, too little, or just the right amount.

You might be underfeeding just a little if there's no feed left in the bunk. For this situation, Hoffman advised feeding 2 percent more the next day, and assessing the bunk's condition the day after that.

If the right amount is being fed, you'll find a few scattered particles of feed remaining. But if you're overfeeding just a bit, you'll see numerous feed particles remaining. However, they'll be individual particles, not a small pile. You're overfeeding a notch more if feed covers the bottom of the bunk, but it's less than an inch deep.

If you're overfeeding even more than that, you'll find a deep layer of feed more than an inch thick covering the bottom of the bunk. And if you're greatly overfeeding, you'll see feed that has been undisturbed.

Wrapping up, Hoffman suggested that farmers, heifer growers and nutritionists talk about improving feed efficiency. It's a talk that could yield cost savings.

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