College of ACES
College News

Condolences on the Passing of Dr. Dan Padberg

Published December 22, 2016

Our deepest condolences to those who knew and loved Dr. Dan Padberg, former Head and professor emeritus in the Department of ACE. Friends and family remember Dan as a wonderful friend, exceptional mentor, and devoted teacher. He was a kind and loving member of the Illinois community, and he will be dearly missed.

You may find his full obituary here:

News Source:

Caroline Ewing

Research at Illinois studies importance of threonine:lysine ratio in pig diets

Published December 20, 2016


  • The ideal threonine:lysine ratio in diets fed to growing pigs has not yet been conclusively established.
  • High levels of dietary fiber may increase the requirement for threonine in the diet.
  • A threonine:lysine ratio of 0.71 was required to optimize average daily gain in pigs fed high-fiber diets, compared with a ratio 0.66 for pigs fed low fiber-diets.

URBANA, Ill. – To optimize performance in growing pigs, it is important to feed not only enough protein, but the right balance of amino acids. Research from the University of Illinois is helping to determine the correct ratio of threonine to lysine in pig diets, and how this ratio is affected by the fiber content of the diets.

Hans H. Stein, professor of animal sciences at Illinois, explains that because producers are increasingly feeding lower-cost, high-fiber coproducts, it's important to understand how dietary fiber affects pigs' nutritional needs. "There's been some confusion about the ideal threonine to lysine ratio,” says Stein. “We think one reason may be that studies have been conducted using diets with different levels of dietary fiber."

Stein says that increased levels of dietary fiber may result in a greater requirement for threonine because of decreased transit time of digesta, increased endogenous loss of threonine, and increased microbial activity in the hindgut.

A team of researchers headed by Stein formulated low-fiber diets based on corn, field peas, soybean meal, and corn starch, as well as high-fiber diets in which the corn starch was replaced by soybean hulls. Both low- and high-fiber diets were then supplemented with threonine to achieve a standardized ileal digestible threonine:lysine (SID Thr:Lys) ratio of 0.45, 0.54, 0.63, 0.72, 0.81, or 0.90.

After analyzing growth performance data for pigs fed the twelve experimental diets, Stein's team estimated that the ideal Thr:Lys ratio for optimizing the gain:feed ratio was 0.63 for both low- and high-fiber diets. However, to optimize average daily gain, pigs fed low-fiber diets required a Thr:Lys ratio of 0.66, whereas pigs fed the high-fiber diets required a ratio of 0.71.

"This increase in the estimated requirement indicates that the presence of soybean hulls, a source of both soluble and insoluble fiber, in the diet increases the requirement for threonine in growing pigs," says Stein.

Funding for this research was provided by Ajinomoto Heartland (Chicago, IL), and by Evonik Nutrition & Care GmbH (Hanau-Wolfgang, Germany).

The paper, "Effects of dietary fiber on the ideal standardized ileal digestible threonine:lysine ratio for twenty-five to fifty kilogram growing gilts," was co-authored by John Mathai of Illinois,  John Htoo of Evonik Nutrition & Care GmbH, John Thomson of Evonik Degussa Corporation in Kennesaw, Georgia, and Kevin Touchette of Ajinomoto Heartland Inc. It was published in a recent issue of the Journal of Animal Science, and can be found online at

Will climate change leave tropical birds hung out to dry?

Published December 20, 2016
red-capped manakin
Red-capped manakin. Photo credit Jeff Brawn


  • Tropical birds may be especially vulnerable to changes in rainfall and length of the dry season.
  • Extreme El Niño events may become more common with climate change.
  • In a University of Illinois study, nearly one-third of the 20 species studied in Panama may decrease if conditions become dryer.

URBANA, Ill. – The future of the red-capped manakin and other tropical birds in Panama looks bleak. A University of Illinois research project spanning more than three decades and simulating another five decades analyzes how changes in rainfall will affect bird populations. The results show that for 19 of the 20 species included in the study, there may be significantly fewer birds if conditions become dryer.

The study took place in Panama’s Soberania National Park. It is approximately 100 square miles of protected rainforest in central Panama and home to well over 500 bird species. In the region, about 90 percent of the annual rainfall occurs in the wet season, typically from late April to early January.  The key result of the study is that with longer dry seasons and more intense seasonal drought, there is an overall negative effect on bird populations. With climate change, there may be longer dry seasons. This is not good news for the birds.

“We caught over 250 different species in mist nets, but only had enough data to model 20 of the most common,” says Jeff Brawn, U of I ecologist and department head of Natural Resources and Environmental Sciences in the College of Agricultural, Consumer and Environmental Sciences. “Capture-mark-recapture is the key. We let them go and then capture them again. How many we recapture is how we estimate survival rate and the changes in the size of the population."

Only one of the 20 species in the study tended to increase with dryer conditionsthe scaly-throated leaftosser. “That one seemed to have a favorable reaction to changes in seasonal drought. We don’t know why. It just consistently seemed to do better,” Brawn says.

What makes this study unique is the duration. “You can’t study the effect of changing environmental conditions and its relationship to bird populations without a long-term study and long-term data,” Brawn says. It is also one of the longest and first studies to examine tropical bird populations and climate change.

Data from1977 to 2011 became the basis of the simulation for the study. Brawn’s team looked at the relationship between population growth rates and the length of the dry season during those 33 years, then simulated another 50 years with an average of a 10 percent change in the rainfall pattern in Panama’s dry season. The full 10 percent change is only about 12 days longer, which isn’t a big time difference. The simulation suggests that, in time, the bird community will be very different under dryer conditions.

Seasonality in Panama is rain/no rain, says Brawn. “Because the tropics are relatively stable weather wise, tropical birds aren’t able to handle environmental disturbances as easily, physiologically or behaviorally, as temperate-zone birds. Birds in the Midwest have below-zero winters and 100-degree summers—environmental stress that tropical birds never experience. Consequently, tropical ecosystems and animal populations may be more vulnerable to the effects of climate change.”

In 1993 and 1998, there were distinct El Niño events, which in that area of Panama means a longer dry season with less rain. Climatologists expect these events to become more common with climate change. Under these conditions, reduced populations of tropical birds may result in fewer birds to provide vital ecological services. Birds eat insects and prevent damage to the trees. They disperse seeds. They pollinate. Because of this, the ecological effect from bird species loss is potentially far reaching.

“And keep in mind that this study looked at just a small slice of the bird community in this forest. There are hundreds of bird species who live in the upper canopy, high above the reach of our mist nets. They’re harder to capture so we don’t have data on those species or those that are rarer.”

The fact that this kind of negative affect on a large population of avian populations can happen in a national park draws even more concern, Brawn says. “We worked in a good forest—that is, relatively intact. The study shows that even in a protected park, the large, global effect of climate change could make a lot of habitat unsuitable for a lot of species.

“Modeling out results into the future, the logical outcome of that is that there will be winners and losers,” Brawn says. “Some species will do very poorly and some will do well but the bottom line is, the tropics will be very different than what we experience now. We’re not saying it will be a silent forest but it will sound dramatically different 100 years from now with songs from only those species who persist.”

Interestingly, this research didn’t begin as a study in climate change. James Karr began charting the demography of tropical birds as a U of I graduate student. Later, he became Deputy Director of the Smithsonian Tropical Research Institute (STRI). Brawn had a post-doctorate position with Karr at STRI. In about 1991, Karr handed over the reins and Brawn continued the work in Panama. Decades later, tropical forest ecologists began reporting that some tree species are sensitive to more intense seasonal drought. Atmospheric modelers predicted the length of the dry season may dramatically change in the tropics, making it shorter in some places and longer in others. Brawn connected the dots, applying the annual changes in rainfall to bird populations.

The study, “Impacts of Changing Rainfall Regime on the Demography of Tropical Birds,” appears in Nature Climate Change and is available online. It was authored by Jeffrey D. Brawn and Thomas J. Benson from U of I, Maria Stager and Nicholas D. Sly from the University of Montana, and Corey E. Tarwater from the University of Wyoming.

Funding was provided by the National Science Foundation (IBN-0212587), the U.S Department of Defense Legacy Resource Program, the U.S. Department of Agriculture National Institute of Food and Agriculture (Accession #875-370), the University of Illinois, and the Environmental Science Program from the Smithsonian Tropical Research Institute. 

Statewide program for agricultural workers with disabilities gains support

Published December 16, 2016

URBANA, Ill. - AgrAbility Unlimited, a state-wide program promoting independence in agriculture for people with disabilities and their families, has acquired renewed funding from the U.S. Department of Agriculture.

Authorized by the 1990 Farm Bill, in 1991 the U.S. Department of Agriculture initiated funding for state-level programs to provide information on accommodating disability in agriculture. “The funding is provided through a competitive grant process,” says Robert Aherin, professor of agricultural and biological engineering at the University of Illinois, and program director of AgrAbility Unlimited. “Illinois is one of 24 states operating individually with this funding.”

The University of Illinois Extension is the lead organization in collaboration with Macon Resources Inc., The Illinois Assistive Technology Program, and Community Health Partnership of Illinois. These organizations have combined their expertise in agriculture, assistive technology, and disabilities to form AgrAbility Unlimited, a program to promote independence and productivity for Illinois agricultural workers who have experienced physical limitations do to a disabling injury or illness as a result of an accident, disease or age related health problem. “Through AgrAbility Unlimited,” says Aherin, “our goal is to assist farmers, their families, migrant workers, and farm workers to improve their quality of life.”

The program has also received private support from the Illinois Farm Bureau, 1st Farm Credit, the IAA Foundation, Growmark, Co-Bank, Farm Credit Services, The Brandt Foundation, Susan Vinckel Trust, Ullrich Foundation, and contributions from individuals.

Aherin says the program seeks ways to mitigate the effects of disabling illnesses and accidents through understanding each individual’s needs and then assisting them through a network of local agricultural and rehabilitation specialists, equipment modification ideas, job restructuring, and if needed, alternative job development. “If there is a need for financial assistance in covering assistive technology cost,” says Aherin, “we will assist clients in obtaining the needed financial resources if they meet certain financial qualifications.” 

All AgrAbility Unlimited services are free of charge and the confidentiality of those who contact the program is held at the highest regard. To allow easy access to these services, there is a toll-free  information and referral hotline. In Illinois, call 1-844-876-5623.  Visit  to learn more.

For more information contact Aherin at 217-333-9417,, or Kelly Gagnon, AgrAbility Unlimited marketing coordinator, at 217-875-8880,

News Source:

Robert Aherin, 217-333-9417

News Writer:

Leanne Lucas, 217-244-9085

New Farm Policy News website

Published December 16, 2016
corn, sky, moon

URBANA, Ill. - Fans of Keith Good’s website who were sad to see it discontinued in 2015 will be happy to hear about his new University of Illinois blogsite.

The site,, features topics of interest to Corn Belt farmers such as: land values, farm income variables, agricultural production estimates, Farm Bill developments, trade issues, biofuels news, regulatory proposals, and other topics that are impacting the agricultural economy.

Good says he draws from many different resources when reviewing a topic to post on the site. “I use current newspaper articles, government reports, extension updates, Federal Reserve Bank reports, Congressional hearings, and news releases to disseminate easy-to-digest, informative posts.”

The content of the new Farm Policy News blog is of interest to a diverse audience. The site was created to expand the reach of the popular farmdoc and farmdoc daily efforts and supplement that information with timely and relevant policy news and economic information. Both farmdoc and farmdoc daily are managed by the Department of Agricultural and Consumer Economics in the College of Agricultural, Consumer and Environmental Sciences at U of I.

How will the new site be different from Good’s former

Good says, “Rather than a comprehensive update containing most of the developments in the latest news cycle, the updates at the new site will be more narrowly tailored to one particular topic that is currently in the news. 

“In addition, unlike the old site, where updates were posted on a strict early-morning deadline each weekday, posts at the new site will be made about four times a week and will likely be posted at various times during the day.”

Anyone interested in receiving regular updates can subscribe to Farm Policy News via an RSS feed or through social media including Facebook, Twitter, Instagram, and LinkedIn.


News Source:

Keith Good