For decades, Animal Sciences in Purdue Agriculture put most or all of its research emphasis on improving animal production and getting food safely from the farm to the table.
That’s still a major thrust today, but scientific advances in the last 20 years or so have given researchers opportunities to learn much more from the animals they study.
“Now we know that these animals can be used effectively as models for other purposes, such as human health,” says Alan Sutton, interim head of the Department of Animal Sciences. “Productivity and the efficiency of production are still important, but now we are providing some very basic scientific information that can help in other areas as well.”
Sutton says advances in gene regulation, stem cells, molecular biology and a number of other research areas have boosted fields such as animal well-being and comparative medicine—which uses animals as models to advance human health—in addition to production agriculture. He says Purdue may be the top university in animal well-being, based on the number of faculty in the field, including adjunct faculty with the U.S. Department of Agriculture’s Agricultural Research Service Livestock Behavior Unit on campus.
“We’ve been able to achieve some real positive results and solutions in these areas,” Sutton says. “We’re going to have some more real breakthroughs in the future.”
Calcium Important for Hens, Too
Scotti Hester, an animal sciences poultry physiologist, is trying to make one of those breakthroughs with chickens—specifically eliminating osteoporosis in egg-laying hens, which can cause broken bones during egg production. Because a vast majority of an egg’s shell is calcium, laying hens can experience significant deficiencies in the mineral that keeps bones strong.
“Hens take a tremendous amount of calcium and put it into the egg shells,” Hester says. “After they’ve been laying for a few months up to a year, their bones get thin. As a result, they can experience a lot of broken bones and chronic pain.”
In addition to being an animal well-being issue for the hens, it can create a serious dent in profits for egg producers. Hester says that although overall hen mortality is low in commercial production systems, 20 to 35 percent of all hen mortalities are due to osteoporosis. On large egg farms, that loss could account for millions of eggs.
Adding to the loss, Hester says manufacturers seldom use these hens at the end of their egg-laying cycles as a source of meat because of concerns over splintered bones in food products.
“There’s a welfare issue from the standpoint of the hen, and there is a food safety issue from the consumer point of view,” Hester says.
Hester has studied the problem for more than 10 years. She’s trying to understand when osteoporosis occurs in the life cycle of a hen, which bones are most susceptible to breakage and how the stress of broken bones affects them.
Using genetics to reduce the incidence of osteoporosis may be difficult, Hester says, because her research suggests that there are many genes involved in bone strength. In humans, childhood exercise has a greater influence on adult skeletal health than any intervention plan in adulthood. So Hester is focusing on the use of perches for pullets that might strengthen bones early in life through increased activity or exercise.
“We’re thinking that early intervention may be the key,” Hester says.