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By Becky Beyers
Every year, about 49 million turkeys are produced in Minnesota, more than anywhere else in the nation.
But how do you get that many birds to market? It’s not as simple as one might think. Turkeys don’t reproduce easily, and the cost of feeding them until they reach market size can make or break a producer. Poultry scientists in CFANS have been studying turkeys for over a century, and their work continues today, concentrating in particular on reproduction and turkey feeding and growth issues.
Modern commercially grown turkeys can’t breed naturally because over the last few decades, breeders have been selecting for fast growth and large, meaty breasts. Artificial insemination arrived in turkey barns in the 1960s and now virtually all domestic turkeys reproduce only with help. Turkey reproductive cycles are affected by light, so they produce the most eggs when photoperiods—daylight—last for at least 14 hours. That might work fine in nature, but not in modern year-round turkey production.
Mohamed El Halawani, a professor in the Department of Animal Science, says turkeys “see” light for reproduction through their brains rather than through their eyes, and they seem to have a specific gene that allows them to sense the passing of another night/day cycle. A series of experiments he’s now conducting at the Rosemount Research and Outreach Center will explore how different parts of the light spectrum affect the birds’ photostimulation and photorefractoriness—how they know when it’s time to start and stop laying eggs, as well as which parts of their brains trigger which activities.
The eggs each hen lays over a period of about 20 to 30 weeks generally go to hatcheries, but occasionally a hen will “get broody” and try to hatch her eggs in the nest—which means the end of egg production for that season. A few years ago, El Halawani and his colleagues discovered that broodiness is caused by a specific brain chemical known as vasoactive intestinal peptide, and could be prevented with a vaccine; the technology has been patented, but so far has not been commercially adopted.
The research could have major implications for producers, as El Halawani and his colleagues noted in documentation for funding the light-spectrum research. Assume that each fertile egg costs about 68 cents, and hens average 75 to 120 eggs in a season; multiply that by the typical 5,000 to 20,000 hens in a flock and a producer could lose many thousands of dollars in a single season if a whole flock of hens wasn’t able to lay eggs.
Turkeys eat a lot, because they grow fast and are sent to market at heavier weights than other poultry; toms are sent to market at between about 18 and 22 weeks. By some estimates, about 70 percent of the cost of raising a turkey is in feed, says Sally Noll (’74–B.S.; ’78–M.S.; ’85–Ph.D., animal sciences), a professor in the animal science department who specializes in poultry nutrition. In recent years, much of that work has focused on how distiller’s dried grains with solubles (DDGS), a byproduct of ethanol production, can be used as animal feed. When DDGS is priced economically as compared to other types of grain, it’s attractive as a substitute turkey feed.
“When we first started looking at this about 10 years ago, the industry was asking us a lot of questions—what is the nutrient composition, what’s the quality, how much can you put into the turkeys’ diet, and what other things might influence using DDGS as feed,” Noll says. Because turkeys are raised to about 20 weeks before going to market, the research is time-consuming. But so far her team has found that turkeys can tolerate a fairly high level of corn DDGS in their diet, as much as 20 percent for toms in a research setting. The turkeys do best if the DDGS level returns to 10 percent in the last few weeks prior to market, she says.
As the ethanol industry evolves, the makeup of DDGS will too, so research likely will be ongoing. Scientists also want to look at other effects of a new diet, such as whether it influences the amount of ammonia released in turkey waste, and how different additives such as added fat or supplements might affect turkeys’ growth on a DDGS diet.
Turkey science in CFANS faces some challenges: research animals are expensive, so most work involves an industry partner. Willmar Poultry Company, for example, is providing the turkeys for El Halawani’s study at Rosemount. The Rosemount facility, one of a few university turkey research facilities in the country, could be displaced or moved as part of UMore Park development at the site. Perhaps most troubling, Noll says, is the dwindling number of students being trained in poultry science, despite high demand from the industry.
“It’s starting to get to a crisis situation,” she says. Companies looking for a poultry nutritionist find it can take up to a year to hire one, and even fewer graduates go into academic poultry-science roles. Challenges remain to find interested students and the required funding for training. While major advances in turkey production have helped expand the industry dramatically over the last 50 years, plenty of challenges remain in breeding: stronger legs to support ever-larger birds, finding ways to boost immune responses and more work on the birds’ well-being.
“People ask me all the time why we’re the number-one turkey producing state,” says Steve Olson (’87–B.S., agricultural education), executive director of the Minnesota Turkey Growers Association. “One of the big reasons is the industry infrastructure we have, including the university.”
Noll and El Halawani are respected nationally for their work, Olson says, and having them here helps producers and processors identify challenges and opportunities as they arise. “They’ve really been crucial to the growth in our industry.”
Source: National Turkey Federation
