Herd Nutrition

By Mark Parker
Progressive Farmer Contributing Editor

"Bred," the veterinarian called out from the back of the chute. The gates fly open, and a heifer scrambles out as another takes her place. She, too, is bred.

That's good news for Bartlett, Kansas, rancher Mike Landrith. Like any cattleman, he's hoping for a calf inside every single heifer moving up the alley. The "bred" or "open" designation has a big impact on Landrith Cattle Company's nutrition program at a time when the winter feed price tag is going to be even higher than usual.

"We'll save the higher-quality forage for the bred cows," he explained. "The open cows will winter on lower-quality hay and pasture; that's if we keep them."

That "if" is a huge decision this year, Landrith said. "With our high-value heifers from the show-calf herd, we might consider rolling an open female over to the next season and transition a spring calver into a fall calver. But in the commercial herd, they'll go to town. It's too expensive to winter an open cow, especially now with high feed costs and high cull prices."

Against a backdrop of a short hay crop, overworked pastures and high grain prices, University of Missouri beef nutritionist Justin Sexten said cow/calf operators need to manage the nutritional side of their operations more closely than ever this year. Here are his tips for making the most efficient use of feed, as producers move toward breeding season.

1. Use a dewormer. Something as simple as deworming could make a big difference in the amount of nutrition the herd is getting. "As feed costs increase, the last thing you want to do is feed parasites," Sexten said. "Deworming is about the easiest thing you can do to make the most of the nutrition your cows receive. Don't put cows through the chute just for deworming, but match it up with other work, such as palpation or weaning."

2. Feed by need. The notion of keeping an open cow through the winter is challenging because next year's calf needs to be twice as good to make up for the loss. But if you don't send open cows to town, separate them from pregnant cows to make it easier to prioritize feed.

Higher-quality forage should go to the cows with higher nutritional requirements, he said.

"In a controlled grazing situation, you can send bred cows through pastures first to harvest the better forage. Follow them with dry cows with lower nutritional needs," Sexten explained.

3. Wean earlier. Weaning a calf reduces that dam's dry matter intake by about 0.5 pounds per 100 pounds of body weight. For a 1,200-pound cow, the result is 6 pounds less daily forage consumption. And because she's no longer lactating, this is a good opportunity for her to regain body condition. Ideally, cows should calve at a Body Condition Score of 5 and young cows at a 6 to facilitate rebreeding.

Try an Ionophore. Ionophores like Rumensin are labeled for use in cows and can reduce maintenance requirements by 10%. "This is an often-overlooked alternative," Sexten observed. "The catch is you have to be feeding at least a pound of supplement every day, so it's only a good option if you're going to be feeding supplement anyway."

4. Test hay. Testing the nutritive value of standing forage or hay can make a big difference in supplement costs as well as provide a guideline for adequate nutrition. At $200 per ton, being able to reduce supplement from 4 pounds to 3 pounds for 60 days cuts per-head costs by $6 during that period.

5. Plan grazing. Don't let cows make the grazing decisions. Use combinations of stockpiled forage and hay to extend grazing, if possible. Strip-grazing can extend the quality of stockpiled grass or crop residues by limiting degradation caused by trampling and fouling.

6. Protect hay. Restricted access time to hay, or limit-feeding, has been proven to reduce hay waste. But Sexten points out low-quality hay cannot be used in limit-fed systems since each bite is important from a nutritional standpoint.

A common cause of hay loss is poor storage or improper feeding methods. For outside storage, big round bales should be in north-south rows, flat end to flat end, with 3 feet between rows, preferably on a slight slope with a gravel base. Skirted feeders that hold hay away from the ring reduce waste. In the case of unrolling or feeding processed hay, Sexten advises supplying only what a particular cow group needs.

"Feed to their requirements rather than just putting out hay," he said. "Efforts to prevent waste result in reduced feed cost, and, as costs increase, limiting waste becomes increasingly important."

7. Make the most of minerals. In a drought, cattlemen may find they need to adjust minerals to make up for the unusual conditions.

Kansas State University cow-calf nutritionist K.C. Olson cautioned water quality can play a role in determining the right course to take.

"When surface water is the main drinking source, keep in mind minerals can become highly concentrated in a drought situation," he said. "An alternative water supply may be necessary."

Higher sulfur concentrations in pond water can interfere with copper metabolism and exacerbate copper deficiency. That's especially important for producers feeding high sulfur supplements, such as dried distillers' grains or corn gluten feed. High sulfur intake can be toxic, causing central nervous system symptoms including agitation, aggressiveness, aimless wandering, blindness and death.

Major minerals required by beef cattle include calcium, phosphorus, magnesium, potassium, sodium, chlorine and sulfur. Trace amounts of iron, zinc, manganese, copper, iodine, cobalt and selenium are also needed.

Requirements vary with age, size, sex and physiological state. A lactating cow, for example, requires 0.27% calcium compared to 0.18% for a dry cow.

"Producers tend to be more cautious in a drought and can overfeed supplemental minerals to make up for any perceived shortcoming in forage quality or availability," Olson noted.

"A good, balanced mineral program is important, but it's also important to have an idea of the seasonal mineral content of the forages in a given region and balance that against the mineral requirements of the cattle," he reminded.

(VM/CZ)

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