Oil is energy, as anyone who has ever tried to balance a swine ration knows. Oil is more than twice as energy-dense as starch, yet producers' main energy source-corn-currently contains just four-per-cent oil. New high-oil hybrids boasting oil levels of six per cent and higher, will start hitting the Ontario market this winter.
The world's biggest seed companies are betting that North America's pork industry will jump to high-oil corn in order to cut feed costs and improve bottom lines.
"We see a two-per-cent improvement in feed conversion for every one-per-cent increase in oil content," explains Doug Yungblut, nutritionist for Pioneer Hi-Bred.
Seed companies are taking different approaches, especially DuPont, whose TopCross system represents a major break from traditional corn production, both in the way it's bred and in the way it must be grown in the field.
Each bag of TopCross seed actually contains two corn varieties. Roughly eight per cent of the seeds produce a high-oil plant capable of setting seed with oil contents up to 14 per cent. These high-oil plants have poor yield potential, however.
The other 92 per cent of the seed produces a competitive, high-yield corn with the traditional four-per-cent oil.
Breeders have learned that if they use the pollen from the high-oil hybrids to fertilize the high-yield hybrids, they can get solid yields of corn that average about seven-per-cent oil.
The first trick for breeders is to use advanced genetics to sterilize the tassels of high yield corn so they cannot fertilize themselves. The second trick is to use the right combination of high-oil and high-yield corn to ensure the high-oil corn is pollinating at the same time that the high-yield corn is silking, thus ensuring the two, as seed corn growers say, don't "miss the knick."
Growers will get the best results if they isolate their high-oil fields from sources of conventional corn pollen. As well, they will have to get used to looking at fields that appear more ragged than conventional corn crops.
Mycogen takes a single-seed approach. But Bert Innis, Canadian research manager for Mycogen, says the goal is the same: to increase the size of the oil-rich germ portion of the kernel, and to make the germ even richer than usual in oil.
Mycogen is introducing its first Ontario high-oil corn for sales starting this fall. Still known at press time by its experimental number 27663, it's a 3200-heat-unit single-cross hybrid that is averaging about seven-per-cent oil, offering "competitive" grain yields, Innis says. "It won't be your highest yielding hybrid, but it won't be your lowest either."
The hybrid is the result of collaboration between Mycogen and DowElanco, and like most of the high-oil hybrids that Mycogen hopes to release in the next few years, it can be grown like conventional corn, with no need for isolation. From the road, and even from the combine, it will look like a perfectly ordinary corn field.
Pioneer's 34M55, a 3400-heat-unit single-cross, marks the corn giant's first high-oil release for Canada. 34M55 is averaging 5.7-per-cent oil content. For a swine or poultry farmer, one bushel of 34M55 offers five to 10 per cent more feed value than a bushel of conventional corn, Yungblut says.
He adds that since the added oil comes from a bigger germ, pork producers will see extra benefits. The germ, for instance, provides higher quality protein and contains a lysine bonus, reducing producers' soy meal or supplement needs.
High-oil corn is more palatable, reduces dust levels and may make it easier to process and handle feeds.
Yungblut points out, however, that high-oil corn may have to be managed carefully, especially in finisher rations. The extra vegetable oil may have the potential to change the fat profile of the pig, so it contains more unsaturated and less saturated fat. The danger is that if high oil corn is fed at large rates too close to market, the carcass fat will turn out unacceptably soft.
Novartis, Pioneer, Mycogen and DeKalb are moving toward the market with TopCross hybrids in Ontario.
"We won't be there until 1999," says DeKalb Canada manager Mike McGuire. "Most of the TopCross development work has occurred with hybrids that are too long-day for Ontario."
Still, it's clear the race is on, and that the seed companies expect high-oil hybrids will be a prominent sector of future seed corn markets. "When swine producers see what these hybrids can do for them in their barns," McGuire says, "high-oil is what they're going to demand."
New corn hybrids that contain a special low-phytate gene promise to make a pound of pork cheaper to produce and easier on the environment.
Phosphorus is a tough element no matter how you look at it. In the environment, if it's washed with run-off into streams, ponds and lakes, phosphorus is an aggressive fertilizer for algae. They multiply quickly, and when they begin to die, their rotting bodies tie up so much of the water's free oxygen that fish suffocate.
Farmers have the opposite problem. In a corn field, for instance, the soil may have lots of phosphorus, but it isn't all located where it's needed. So corn growers still apply phosphorus starter fertilizers to make sure their young seedlings can reach enough phosphate with their tiny root systems.
Pork producers who feed the corn are actually giving their pigs a diet rich in phosphorus. But because the phosphorus is tied up in a molecule called phytate - a molecule that pigs and other monogastrics can't digest - at least two-thirds of the corn phosphorus gets excreted in manure.
New genes, however, have the power to make the corn plant store up to 80 per cent of its phosphorus in an inorganic form that pigs can use.
Discovered by Victor Raboy, geneticist for the U.S. agriculture department, the genes are being developed under a special collaborative agreement with Pioneer Hi-Bred and will hit the U.S. market with limited seed supplies in 1998.
Ontario pork producers will have to wait a couple of extra years. But Doug Yungblut, nutritionist for Pioneer, expects that within 10 years the low-phytate gene will be a regular part of most Pioneer hybrids.
Yungblut says pork producers will be able reduce or even eliminate phosphorus supplementation, and worry less about building soil phosphate levels too high.
While the hybrids are called low-phytate because of the way phosphorus is manipulated inside the plant, Yungblut thinks many pork producers will think of them with the other name that's catching on in the U.S. - "high-available phosphorus hybrids."
Tom Sauber, pork nutrition team leader for Pioneer in Des Moines, Iowa, believes that cash croppers will also grow identity-preserved low-phytate corn, sometimes on contract for a pork-producing neighbour and sometimes on contract for feed mills.
"We are expecting that demand for low-phytate corn will exist at all levels," Sauber says. "The pork producer who grows his own grain will most easily adopt the practice, but the rate of adoption could actually be faster among producers who do not grow enough corn for their total needs."
Pork producers with limited field crop acreage, he explains, are already looking to low-phytate corn to help them reduce the phosphate loadings on their soil.
Tests by Michael Schmitt of the University of Minnesota-St. Paul show that when swine are fed low-phytate corn, manure that would normally contain 35 pounds of phosphorus per 1,000 gallons drops to 19 pounds per 1,000 gallons.
Typically, farmers who rely exclusively on swine manure to meet their corn's nitrogen needs end up applying three times too much phosphorus, Schmitt says.
He is in the middle of a three-year project with Pioneer and Raboy to identify the best production practices for low-phytate corn. Schmitt is trying to find out, for instance, whether the soil's phosphorus levels have any impact on the amount of inorganic phosphorus in corn produced by the low-phytate hybrids.
There's a concern that the most powerful of Raboy's genes, which are able to reduce phytate by up to 95 per cent, may also hurt germination and yield potential.
"When low-phytate corn is commercially available, growers will have questions about how the corn will perform on the farm under varying soil phosphorus levels," Schmitt says. "Our research will provide answers."
While many pork producers will switch to low-phytate hybrids largely to escape the cost of phosphorus supplements, Raboy believes the environment will also be a big winner.
A study by University of Kentucky researcher Gary Cromwell indicates that American hog and poultry farms produce enough manure every year to fill a train long enough to circle the earth. According to Cromwell's study, the annual manure production from U.S. farms weighs 30 million tons and contains 460,000 tones of phosphorus, enough for 150 million 50-pound bags of 12-12-12 fertilizer.
The burning question of what causes ulcers in pigs is being answered
with the assistance of research into human ulcers.
"Everything we know about ulcers has been turned upside down in humans
the last five years," says Bob Friendship, research co-ordinator, University
of Guelph. A major culprit in human ulcers is now known to be a bacteria
named helicobacter pylori.
Friendship notes that people who were once treated for ulcers throughout
their lives now rid themselves of the problem with a course of antibiotic
therapy. Could a bacteria with an equally simple cure be involved in gastric
ulcers in swine?
"Maybe," says Friendship, although he emphasizes that swine and human
digestive systems differ. Brazilian researchers have discovered a tightly
coiled cousin of the human bacteria named helicobacter heilmannii in a
group of heavily ulcerated pigs.
Many pork producers continue to sacrifice production efficiency by feeding
coarse ground feed, a traditional precaution against ulcers. For some,
it's a question of trading sometimes severe death loss for reduced rate
of gain and higher consumption.
Friendship emphasizes that research to date has yet to prove anything.
He also believes that, just as alcohol and aspirin have been shown to contribute
to human ulcers in addition to bacteria, there are probably several causes
of ulcers in swine.
"It's one of those issues that isn't going away; it's probably getting
worse," Friendship says of gastric ulcers in swine. That leaves the present
focus on feed particle size.
A 1996 survey of 93 Ontario farms using hammer mills found that feed
particle size ranged from 690 microns to 1,497 microns. Only 30 per cent
of the farms sampled had feed in the correct range, which Friendship describes
as between 600 and 800 microns. Feed ground finer than this increases the
risk of ulcers.
Fig. One, page 14, shows that feed efficiency is best with feed ground
as fine as 400 microns. Friendship says his research shows feed conversion
can improve by between three and eight per cent when particle size is reduced
from 1,000 microns to between 600 and 800 microns.
Fig. Two shows average daily gain rose from 0.79 kg to 0.96 kg when
particle size was reduced from 950 microns to 750 microns.
Kenpal Farm Products Inc., Centralia, worked with customers on the 1996
particle size study with Friendship. Kenpal nutritionist Alan Ford says
that "one very positive outcome of the study is an increased awareness
of the importance of particle size."
Both Ford and Friendship say that even before the study Kenpal had a
reputation for strict attention to the size of grind. A sampling outside
the Kenpal customer base might have shown fewer farms hitting the desired
range for fineness.
Nevertheless, most farms studied were grinding their feed too coarse.
Variability, which research suggests is as serious as too fine a grind,
was another problem the study turned up.
Farmatic Mills has been a familiar site on Ontario hog farms for 30
years. Farmatic service manager Richard Faught says the particle size study
hasn't changed anything at his company or its U.S. operation, Mix Mill.
Faught says farmers can usually manage ration grind by selecting the
right screen size and ensuring that hammers and screen aren't worn.
Kenpal's Ford points to other factors that affect particle size and
uniformity. These include grain type, moisture, and the speed at which
producers run their mills.
Slower speeds can permit finer and more uniform feed, but Ford says
some can't afford the extra time involved in making rations more slowly.
Research at Kansas State University has shown that roller mills might improve
uniformity.
However, Faught says roller mills work best with corn. He observes that
roller mills used on dairy farms aren't up to the demands of pig feed.
Faught also notes that a double-reduction roller mill, sometimes referred
to as two pair high, which would do the job, costs far more than a standard
hammer mill.
Ford suggests producers who want to ensure maximum returns purchase
a sieve that measures the size of feed particles. He says the device, which
is used routinely by Kenpal representatives, is available from laboratory
supply outlets and costs about $100.
TO GRIND, OR TOO FINE?
By ROBERT IRWIN
ID:878