There is a child's rhyme which begins, “Hay is for horses. Grass is for cows …” Perhaps this is better advice than most modern cattle producers ever imagined.

A new Iowa study shows properly managed stockpiled winter forage is cheaper and of higher quality than the same forage mix harvested and fed as hay for wintering bred replacement heifers. It puts more weight on them and does it at lower cost. Also, its profitability is less subject to fluctuations in pasture costs than is a hay-feeding program to changes in the price of hay, meaning it has lower financial risk.

This is something most southern cattle raisers have practiced for generations because winter annual forages are prevalent there and winters are comparably mild. “Snow grazing” instead of hay feeding is a less-tried concept, however, from the Midwest on north.

The Iowa State University (ISU) study compares a drylot, hay-based program and a winter-stockpiled forage-based program for developing replacement heifers. It shows a big advantage in body condition for the grazed heifers.

In the two-year study, hay-fed heifers lost 0.1 to 0.2 body condition points on a nine-point scale, even though they met their target weights for calving. Grazed heifers gained from nothing at all to 1.0 body condition points, depending on stocking rate.

Further, in the first year, grazing heifers supplemented to the low target weight got 18 lbs. of corn gluten (CG) feed, while those supplemented to the high target weight got 94 lbs. of CG. In the second year, neither group required any CG to meet their target weights. Compare that with 186 and 286 lbs. of CG in the first and second years needed by the drylot heifers.

Then, don't forget the two tons average diet of hay fed to each drylot heifer vs. no hay fed to the grazing animals.

The good performance posted by the grazing heifers is no surprise if one considers that the standing forage showed a large advantage in the amount of digestible dry matter and a small advantage in crude protein over the hay. The live forage also posted lower levels of acid detergent insoluble nitrogen, a measurement of indigestible protein in the forage.

Is it any wonder then that the researchers were able to develop the grazed heifers for about 50-75% of the cost to develop the drylot heifers? The grazing treatments varied from 61¢/heifer/day to 90¢/ heifer/day. The drylot treatments cost $1.16 the first year and $1.18 the second year.

How They Did It

The heifers were grazed for 127-154 days on an endophyte-free, fescue-clover mixed pasture beginning in late October or early November. The forage was stockpiled from early August. Researchers used two stocking rates — 0.34 heifer/acre and 0.48 heifer/acre. Forage was rationed in each pasture by dividing it into eight strips using temporary electric fence and allowing the heifers l7-21 days in each paddock.

The drylot heifers were given fescue and red clover hay free-choice. CG was fed daily as required to meet the target weights.

Although the two years of the Iowa research project had mild winters with little snow cover, snow cover in 2003-2004 was much heavier and the pastured heifers continued to perform well, adds ISU animal scientist James Russell, lead researcher on the project.

The researchers assigned pasture costs of $60/acre, hay costs of $41/ton, and CG costs of $55/ton.

“What we've found, and I think it's pretty well true across the country, is the largest cost in cow-calf production is feeding stored feeds,” Russell says.

“We had done this (stockpiling) enough that we felt like we had some pretty sound economics on cows. So, of course, the next thing producers wanted to know was ‘What about heifers?’” Russell adds. “So that's how we got into this.”

Talking About Heifers

Past ISU research projects have found cows grazed on cornstalks could get by with 400 lbs. of hay over the winter, vs. nearly three tons of hay for those wintered in drylot, for example.

ISU's studies on cow wintering costs match well with such studies from other Midwest states.

Jim Gerrish, formerly the research agronomist at the Forage Systems Research Center (FSRC) at Linneus, MO, quotes Missouri and Iowa research at 50¢ to 70¢/day higher feed costs for a beef cow fed hay compared to a cow grazing. He says decreasing the hay feeding period to 60 days would save cow-calf producers $40-$60/cow/year.

A Purdue University study in the mid 1990s on adult cows grazing 45-60 days during the second trimester of pregnancy showed similar results. Average hay cost savings when cows grazed corn residue and stockpiled pasture, instead of being fed hay in a drylot, were $24.28 and $14.88/cow, respectively. Cost savings varied from $3.74 to $24.91/cow with use of stockpiled pasture and $11.84 to $41.08/cow with use of corn residues. The cows posted good performance in this study.

A demonstration with grazed heifers at Missouri's FSRC is showing similar success. Area livestock specialist Chris Zumbrunnen says topgrazing of the standing forage by pregnant heifers is providing all the nutrition they need in the third trimester. Calving under those circumstances is much better because there is less mud and the plane of nutrition is excellent. The FSRC typically moves cattle onto new forage strips every three days, giving them greater control and consistency of forage quality than researchers there would get with less-frequent moves.

There is more good news from the ISU study. Russell says grazed heifers, even at the higher stocking rate, exceeded the target weight needed for healthy calving and rebreeding. That means lower pasture costs per heifer could probably be had.

Also, the cost of labor in the two systems was assumed to be equal, but most experienced graziers report they invest much less time on forage systems than they did in drylot/hay systems. That could provide additional cost savings.

This news about grass being better than hay should be no surprise. The industry struggles with a petroleum-dependent mindset which, over the years, made it seem easy to increase hay supplements until they became hay subsistent. As diesel and equipment prices continue to rise — and they will — grass on the ground looks increasingly inviting, and profitable.

Alan Newport is a freelance writer based in Carnegie, OK.

Tips On Snow Grazing

Differing growth traits means some forages are better suited for snow grazing than others. The University of Missouri's Forage Systems Research Center (FSRC) in Linneus has long worked with stockpiled winter grazing similar to that done in the Iowa research project.

Tall fescue or a late-summer-seeded oat crop stand up well under several inches of snow, sometimes up to a foot of dry snow, the center says. Softer grasses, such as orchardgrass or bluegrass, tend to lay down under the snow and be less accessible.

That means soft grasses should be used first, when the fields are open. More erect grasses should be saved for snow times.

The question most producers worry about is this: How much snow will cattle graze through comfortably?

“Producers from across the country have told me they have had their cattle graze through 10-12 in. without a problem,” says Jim Gerrish, former FSRC superintendent. A few will claim deeper depths, he says, but 1 ft. seems to be the practical upper limit.

The type of forage below the snow is an important factor, Gerrish adds. The taller and more erect it is, the deeper the animals will dig. If the forage height is less than 5 in., cows seem to quit grazing.

Adaptability Symposium Set For Oct. 29-30

The consensus is that genetic differences for adaptability exist among cattle. The theory is that an animal adapted to a certain environment is better suited to perform in that environment, and identifying and selecting for those traits would raise production efficiency by extending an animal's longevity, disease resistance, etc.

To further develop that concept, a Cow Adaptability Symposium is set for Oct. 29-30 in Kansas City, MO. The sessions begin at 8 a.m. on Oct. 29, and end at noon the following day. Registration is $150.

Among the presentations are: Australian research on adaptability, adaptation and learning in beef cattle; physiological observations related to beef cattle under stress; role of disease resistance in adaptability; high-altitude disease: an example of genetic variation for adaptability; economic importance of adaptability; an example of selection: cows matched to the production environment; and a discussion on adaptability.

For more detail, go to http://www.ansci.cornell.edu/adaptability/, or contact John Pollak (ejp6@cornell.edu) or Susan Herbert (shh4@cornell.edu) or 607/255-4416.