Researchers uncover what makes some chickens more water efficient than others

By John Lovett
University of Arkansas System Division of Agriculture
Arkansas Agricultural Experiment Station

FAYETTEVILLE, Ark. — In the first scientific report of its kind, researchers in Arkansas showed that chickens bred for water conservation continued to put on weight despite heat stress that would normally slow growth.

STUDY RESULTS — Sara Orlowski, an associate professor of poultry science, compared water intake and food conversion ratios in chickens bred for high, low and normal levels of water efficiency. (U of A System Division of Agriculture photo)

Research by the Arkansas Agricultural Experiment Station indicates the specially bred line of chickens developed by Sara Orlowski could save growers thousands of gallons of water and thousands of pounds of food each month without sacrificing poultry health. Orlowski is an associate professor of poultry science with the University of Arkansas System Division of Agriculture.

As global population increases and usable water diminishes due to climate change patterns, scientists with the Division of Agriculture are looking for ways to raise the world’s most popular meat protein using fewer resources.

The study, which was part of a five-year project funded by a $9.95 million grant from the U.S. Department of Agriculture’s National Institute of Food and Agriculture, showed a broiler chicken’s physiology could be significantly improved to convert food and water to body weight even with three weeks of heat stress.

Results from the study were published in Physiological Reports, the American Physiological Society’s scientific journal, as an article titled “Effect of heat stress on the hypothalamic expression profile of water homeostasis-associated genes in low- and high-water efficient chicken lines.” The grant was awarded through NIFA's Agriculture and Food Research Initiative.

Sami Dridi, professor of poultry science specializing in avian endocrinology and molecular genetics, was responsible for conducting the experiment and the driving force in writing the paper.

Walter Bottje, professor of poultry science for the experiment station, is the project director for the USDA Sustainable Agriculture Systems multi-institutional grant led by the Center of Excellence for Poultry Science.

Now in its fifth generation of selection, the high water-efficient line has been measured to consume significantly less water than standard broiler lines in use today. From the time they were hatched to one month old, the high water-efficient line drank 1.3 pounds less water, and about 5.7 ounces less feed, which calculates to a 32-point improvement in water conversion and six-point improvement in feed conversion when compared to a random-bred control line.

While it may not seem like a huge difference, modern chicken houses hold on average 20,000 to as many as 50,000 birds. Although chickens consume more as they grow, the difference for that month of growing equates to 7,800 fewer gallons of water and 17,800 pounds less feed to grow 50,000 water-efficient chickens.

In some conditions, the high water-efficient chicken had food conversion ratios that were just as good or better, and their water conversion ratio was about 55 to 65 percent better, according to Dridi.

Bottje said these recent results from the ongoing research are promising, but the group aims to investigate other physiological characteristics of the high water-efficient line, such as meat quality and gut integrity.

Thirst control

POULTRY SCIENCE — Sami Dridi is professor of poultry science specializing in avian endocrinology and molecular genetics. (U of A System Division of Agriculture)

The hypothalamus is the part of the brain that controls thirst. One of the study’s findings was that the hypothalamus of water-efficient chickens differed from the other chickens when exposed to heat stress. The investigation revealed potential molecular signatures for water efficiency and heat tolerance in chickens.

The researchers devised a study that induced heat stress for groups of chickens by increasing the ambient temperature to mimic a summer season in Arkansas. The heat-stress cycle began when the birds were 29 days old. The environment was also kept between 30 and 40 percent relative humidity.

Dridi ran a parallel study comparing data on the divergent lines of chickens.

What they found was surprising.

“What the most interesting thing from that study, when it comes to live performance, is that the heat-stressed birds from the high water-efficient line consumed less water than the non-heat stressed birds from the low water-efficient line,” Orlowski said.

Water is critical to raising chickens. They can go several days without food, but only a few hours without water at high temperatures, Dridi said.

Dridi said high humidity, which would be over 70 percent for chickens, also induces similar heat stress because the chickens cool themselves by breathing. Dridi’s studies on poultry house sprinkler systems kept the humidity lower than the industry standard method and used significantly less water than evaporative cooling cells.

“With water sprinkling systems that can save up to 66 percent water usage in a poultry house, the water conservation of poultry could be improved by a magnitude of three- to four-fold by having chickens that consume less water and still retain growth,” Dridi said.

Project development

Dridi said the idea for water-efficient chickens came from looking at the differences in chicken lines bred as far back as the 1950s. Dridi and other researchers wanted to see how much genetic differences there were between jungle fowl and modern breeds.

Before they could breed water-efficient chickens, though, they had to reliably measure the amount of water chickens drank.

Orlowski was a Ph.D. student when her graduate research team developed a novel low-flow water monitoring system in collaboration with Siloam Springs-based companies Alternative Design and Cobb-Vantress Inc., a primary broiler breeder company. The tool was essential to accurately measure water intake for individual birds in real time.

“When we first started this project in 2018, we evaluated one of our broiler lines, a non-selected control population, and we characterized them for water intake,” Orlowski said. “And within that population there was a variability for water intake. From there, we were able to take our most water-efficient families and our least water-efficient families, establish our research populations and continue to select from there.”

A base population of chickens that were not selected for high or low water-efficiency was kept as a control group to compare changes in each generation, Orlowski noted.

Bottje and Dridi said the work done by Orlowski in selecting the divergent lines of chickens was the most important factor of this experiment. Orlowski said water efficiency in the high water-efficient line is continuing to improve with each succeeding generation. She ranks the water efficiency trait as “moderately heritable.”

“There’s no reason that it will not work for all poultry operations, including turkeys, quail and ducks,” Dridi said.

About the researchers

The lead author on the research article was Loujain Aloui of the Higher School of Agriculture of Mograne at the University of Carthage in Zaghouan, Tunisia, while on an internship with the Center of Excellence for Poultry Science and the Division of Agriculture.

Co-authors included Elizabeth S. Green, Travis Tabler, Kentu Lassiter, Bottje, Dridi and Orlowski with the Center of Excellence for Poultry Science at the Division of Agriculture and Kevin Thompson with the Center for Agricultural Data Analytics with the Division of Agriculture.

To learn more about Division of Agriculture research, visit the Arkansas Agricultural Experiment Station website: https://aaes.uada.edu. Follow on Twitter at @ArkAgResearch. To learn more about the Division of Agriculture, visit https://uada.edu/. Follow us on Twitter at @AgInArk. To learn about extension programs in Arkansas, contact your local Cooperative Extension Service agent or visit www.uaex.uada.edu.

Arkansas 4-H members bring the heat to state barbecue contest, advance to nationals

By Rebekah Hall
U of A System Division of Agriculture

ROGERS, Ark. — Sixteen Arkansas youth put their grilling chops to the test at the 4-H State Barbecue Cook-Off, and the first-place winners in chicken and turkey barbecue will advance to the national competition in Louisville, Kentucky.

WINNER WINNER, CHICKEN DINNER — Jeremiah Moix, 18, took first place in the chicken barbecue category with a recipe that focused on his grilling technique and used hickory chips to infuse the chicken with smoky flavor. (Photo submitted by the Moix family.)

The contest was held June 10 in Rogers at the 63rd Annual Poultry Festival, hosted by The Poultry Federation. Jeremiah Moix, 18, was the first-place chicken barbecue winner, and Blakley Thompson, 14, was the first-place turkey barbecue winner. Moix and Thompson will advance to the national competition, which will be held at the National 4-H Poultry and Egg Conference in Louisville, Kentucky, from Nov. 15-16.

Moix has been a member of the Paron Lion’s Pride 4-H Club in Saline County for three years and has competed in the barbecue competition each year since joining.

“I’ve grown up watching my dad grill, so I already knew some basics,” Moix said. “It just sounded like a fun thing to do. We’d never cooked on charcoal, so I had to learn different techniques for that, and I got to learn how to cook chicken.”

Thompson has been a member of Clark County 4-H since he was 5 years old. Thompson said he also shows goats and lambs at the national level. This was his first year competing at the state level of the barbecue contest.

“I just fell in love with turkey because I like the taste of it, and I also like to turkey hunt,” Thompson said. “Turkey is all-around my favorite bird.”

The road to state

Sara Orlowski, assistant professor and extension poultry specialist for the University of Arkansas System Division of Agriculture, coordinates the district and state 4-H barbecue contests. She said 4-H members first compete in the barbecue contest at the county level, starting in March and April. Those winners advance to the district level in one of four district barbecue contests held in Fayetteville, Jonesboro, Arkadelphia and Little Rock. Only 4-H’ers aged 14 and older can move on to the state-level contest.

“One of the big draws is that we hold the state barbecue contest for the 4-H kids at the Poultry Festival,” Orlowski said. “They grill in the morning, and then they spend the rest of the day at the festival. There’s usually a concert at night that the kids get a ticket to go to, so it’s a big weekend for them. They get to come up to Rogers and compete, but also have some fun afterward.”

At the county and district level, participants bring their own grills, but for the 16 youths who qualify for the state competition, a grill is provided for each of them. They then get to take that grill home with them as part of their reward for making it to the state level.

Orlowski said contestants are judged not only on the taste of their barbecue, but also on their preparation and food safety skills.

“There’s a section that they’re scored on before the product is even tasted,” she said. “They’re judged on how well they can light their charcoal grill, how they control their fire and how they put on sauces and check temperatures.”

Contestants also must prepare a trifold poster board with information about safe food handling and the poultry industry, as well as nutritional facts about their chosen meat. This accounts for a quarter of a contestant’s overall score.

Practice makes perfect

Moix said he begins preparing for the county barbecue contest early in the spring.

“Usually at the start of the season I probably haven’t grilled in a while, so for my first practice, I’ll light up the grill outside and I’ll do my food prep in the home kitchen,” Moix said. “But by the time of my last practice before the competition, I have everything set up outside. I’m trying to simulate the competition as much as I can. I come inside to get the chicken and take it outside to prepare it, just like I would in the competition, and I’m timing myself.”

Contestants are allotted two and a half hours from the time they light their grill to the presentation of their dish to the judges.

Moix said his family has tasted many versions of his chicken recipe and provided plenty of feedback.

“My harshest critics are my siblings,” Moix said. “I get pretty immediate feedback — they’ll tell me too much seasoning, or not enough seasoning, or I didn’t get enough smoke in this part of the meat.”

Thompson said that after qualifying in his county competition, he practiced every week for the district contest.

“I worked on getting my timing right,” Thompson said. “I marinated my turkey for the first hour while my fire was getting ready. And I actually didn’t put my turkey on the grates, I put foil down on the grates and then put my turkey on top of that. This was to render the spices and the vegetables that were on the turkey into it, to make it a better-tasting turkey.”

Moix said that over the years he’s competed in the barbecue contest, his recipe hasn’t changed much, but his technique has.

“What I try to go for is a very simple seasoning that’s not very strong or overpowering, but I add some hickory chips to the smoke,” he said. “Getting that into the chicken — which is sometimes harder to do than perfecting your seasoning — to keep it nice and moist, and get crispy skin without burning the skin, that’s really what I’m practicing each time. It’s a simple, good recipe, and it lets my actual grilling technique show through.”

Thompson said that on a trip to Puerto Rico with his family, they met a soldier who worked as a commercial chef, who influenced the flavors Thompson chose for his turkey recipe.

“I’ve always wanted to meet with a chef who’s been all over the country, so my recipe came from Puerto Rico,” he said. “We learned of these flavors from him and then tried them, and it improved the turkey in so many ways.”

The key to Thompson’s recipe is using lots of white vinegar in the marinade, which he says opens the pores of the meat and allows for garlic and peppers to infuse their flavors into the turkey.

Preparing for nationals

Moix said that at the national barbecue contest, competitors must give a 10-minute presentation on the poultry industry and respond to questions from judges.

“It’s a step up from the poster board, and then you have to go grill,” he said. “I’ve taken some speech classes in high school, so I’m pretty confident on that part.”

Thompson said he’s most looking forward to participating in the competition side of the National 4-H Poultry and Egg Conference, as in previous years he’s shown goats and lambs.

“I’m super excited to learn from other people who are big into this,” Thompson said. “Even at the state competition, people are like, ‘Oh, I’ve been here eight times,’ and it’s my first year. I’m excited to meet with the kids who are cooking those chicken and turkeys and have been there in past years and won that contest, to see what it does for you and how it helps.”

For their fellow 4-H’ers interested in the barbecue contest, Moix and Thompson both recommended plenty of practice and keeping a cool head during the competition.

“Every now and then I see people who have barely practiced, and they can sometimes do well based on luck, but if you want to perform well consistently, practice,” Moix said. “Know how much charcoal you’re going to use, know how much seasoning you’re going to use, so that at the competition, it just feels natural and like you’re cooking at home.”

The Arkansas 4-H youth development program is operated by the Cooperative Extension Service, the outreach arm of the Division of Agriculture.

To learn about extension programs in Arkansas, contact your local Cooperative Extension Service agent or visit www.uaex.uada.edu. Follow us on Twitter and Instagram at @AR_Extension. To learn more about Division of Agriculture research, visit the Arkansas Agricultural Experiment Station website: https://aaes.uada.edu. Follow on Twitter at @ArkAgResearch. To learn more about the Division of Agriculture, visit https://uada.edu/. Follow us on Twitter at @AgInArk.