Because of concerns over antimicrobial resistance in humans and the public pushback against antimicrobials in livestock feed, the poultry industry is evolving toward more antibiotic-free production techniques to meet market demands. Penn State researchers are helping to identify and better understand alternative approaches.

The growing need for antibiotic-free products has challenged producers to decrease or completely stop using antimicrobials as feed supplements in the diet of broiler chickens to improve feed efficiency, growth rate, and intestinal health. Led by Erika Ganda, assistant professor of food animal microbiomes, a Penn State research team conducted a study of natural feed additives that are promising alternatives to substitute for antimicrobial growth promoters.

In findings available online now that will be published in the May issue of Poultry Science, the researchers characterized the effects of a probiotic and a blend of essential oils on broilers’ growth and gut health. The team found that supplementing the diet of young chicks with a probiotic over 21 days significantly boosted the abundance of beneficial intestinal microorganisms.

Overall, according to Ganda, research like the work her team conducted is urgently needed to help producers make decisions at the farm. However, she added, the use of these feed additives in broiler production is still in its early stages, and more studies to evaluate the health outcomes, mechanisms and consequences for antimicrobial resistance prevalence will be necessary to better understand the role of feeding antimicrobial growth promoters alternatives on the gastrointestinal tract of broilers.

“Because the elimination of antimicrobial growth promoters use is associated with increases in disease and a decrease in growth performance in chicks, antibiotic-free alternative approaches to enhance intestinal health and improve growth performance are of great interest to the poultry industry,” she said. “The claim that a product is ‘natural’ does not make it necessarily more beneficial than antibiotics, so we conducted this experiment to answer this question.”

In the research, spearheaded by Ana Fonseca, graduate assistant in Ganda’s research group in the College of Agricultural Sciences, a total of 320 one-day-old chicks were raised for 21 days in 32 randomly allocated cages. Treatments consisted of four experimental diets: a standard diet; and a standard diet mixed with the antibiotic bacitracin methylene disalicylate, or an essential oils blend of oregano oil, rosemary and red pepper, or the probiotic Bacillus subtilis.

Probiotics are live microorganisms that, when administered in adequate amounts, confer a health benefit on the host by supporting a more diverse population of beneficial bacteria in the digestive tract. Essential oils are plant-derived extracts that possess various antioxidant, immune-modulating, antimicrobial properties and the ability to change the “microbiome” — in this case, the community of microorganisms living in the chicks’ intestines.

The researchers individually weighed all broiler chickens on day one and then at the end of each dietary phase on day 10 and day 21. The feed consumed per pen was monitored at the end of each growth phase. The team also calculated the daily body weight gain average, feed intake and feed conversion ratio of feed consumed divided by weight gain at three periods: the starter phase of one to 10 days, the grower phase of 11 to 21days and the total period of one to 21 days.

The team collected excreta samples daily during the entire experimental period and analyzed DNA to identify bacteria present. Across all time points, supplementing chicken diets with the probiotic or the antibiotic significantly changed the relative abundance of bacterial strains compared to the standard diet, Fonseca noted. However, there were no microorganisms affected by essential oils compared to the standard diet.

“We were somewhat surprised by the results of the essential oils — we were expecting them not only to have some effects on the microbiome, but also on the performance side,” she said. “We still think essential oils may present a promising alternative to antimicrobial growth promoters, but their effectiveness can be influenced by various factors. We only observed these animals for 21 days, and maybe the essential oils would have more significant effects when they are older, and their microbiome gets more stable. The benefits of essential oils in this context deserves more research.”

Drylands in the western United States are currently in the grips of a 23-year “megadrought,” and one West Virginia University researcher is working to gain a better understanding of this extreme climate event.

Steve Kannenberg, assistant professor of biology at the WVU Eberly College of Arts and Sciences, is using observations from existing networks of scientific instrument stations across the region to inch toward that goal.

The megadrought is an ongoing climate crisis for natural ecosystems, agricultural systems, and human water resources, but researchers have a limited understanding of the phenomenon.

With joint National Science Foundation funding from Ecosystem Science Cluster and the Established Program to Stimulate Competitive Research, commonly known as EPSCoR, Kannenberg is seeking to identify where this drought has been most severe.

Data should reveal where the conditions have depleted groundwater and soil moisture and identify which dryland plants have been most affected.

The term “drylands” refers to areas where water availability limits the health of ecosystems.

“In West Virginia, we have plenty of water,” he said. “But, if you go out to Utah, for example, it’s very hot, very dry. And the health of the vegetation is determined by how much water is in the soil and how much water is in the air.”

Data on the west’s climatological history can be obtained by studying tree growth rings in drylands. Using tree rings, researchers have found the current 23-year drought period is the most severe over the last 1,200 years. Kannenberg will pair tree ring data with measurements of soil moisture, groundwater and ecosystem fluxes via eddy covariance flux towers.

“These are, essentially, fancy weather stations that can sense the ecosystem breathing,” he said. “It can quantify how much carbon is going into the vegetation from the atmosphere as plants photosynthesize during the day, and likewise, how much carbon is breathed out back into the atmosphere at night, because ecosystems respire like we do.”

The towers can also measure how much water is coming in via rain, how much goes out through plants to the atmosphere and how much evaporates from the soil surface.

Globally, megadroughts are projected to increase in frequency and severity in the coming decades, and Kannenberg’s synthesized data may help inform researchers about other dryland and non-dryland biomes.

He’s also focused on carbon capture. The photosynthetic rate of the vegetation across drylands affects their ability to store carbon, but trees can only photosynthesize when there’s sufficient water available. This process is fairly consistent in eastern forests, but difficult to predict in drylands.

“If you think of a forest here in West Virginia, there’s obviously a lot of carbon stored in the vegetation,” he said. “This makes it a very important carbon sink, globally. It’s easy for scientists to predict how much carbon gets taken up by these trees every year because we know that the environment during the spring, summer and fall is pretty conducive to photosynthesis.”

However, with far less vegetation in western landscapes, less carbon is stored in drylands. Water availability is inconsistent and unpredictable, and the amount of carbon western vegetation can take up each year varies significantly. In drought years, little carbon may be absorbed at all.

Iowa environmental groups — inspired by a successful campaign in Minnesota — are asking the U.S. Environmental Protection Agency to step in and protect drinking water in northeast Iowa from agricultural runoff.

The petition was announced this week, hours after the Iowa Environmental Protection Commission unanimously approved largely status quo rules governing animal feeding operations.

“The Environmental Protection Commission has once again proven who they really serve — not the Iowa public, but big ag polluters,” said Alicia Vasto, water program manager for the Iowa Environmental Council, one of the 13 groups that filed the petition with the EPA Tuesday.

The petition asks the EPA to use its emergency authority to intervene in Iowa to “address groundwater contamination that presents an imminent and substantial endangerment to the health of residents in northeastern Iowa.”

“The well-documented nitrate contamination of drinking water in the karst region necessitates prompt and decisive EPA emergency action,” the petition states. “Elevated levels of nitrate in drinking water are known to increase the risk of a wide range of very serious health problems …”

According to the National Institutes of Health, nitrate and nitrite ions are widespread in the environment and occur naturally in plant foods and water, however they are also regularly found in inorganic fertilizer. A 2018 review of 30 academic studies showed a link between ingesting nitrate from drinking water and adult diseases, including colorectal cancer. Other University of Iowa studies show nitrate consumption may cause bladder and ovarian cancer in older women, The Gazette reported last month.

Nitrate is found at potentially harmful levels in 1-in-20 Iowa public drinking water systems and in more than 12,000 private wells in Iowa.

The petition focuses on Iowa’s Driftless region, where porous karst terrain makes streams and groundwater particularly vulnerable to fertilizer or manure runoff.

Just across the state border to the north, the EPA in November told the Minnesota Pollution Control Agency to develop a plan for addressing nitrate levels in drinking water sources in southeastern Minnesota. This EPA demand came six months after environmental groups in Minnesota filed a petition comparable to what Iowa groups filed Tuesday.

“We’ve seen similar increases in nitrate in drinking water sources just like in Minnesota,” said Michael Schmidt, an attorney for Iowa Environmental Council. “We would expect the EPA to do at least as much in Iowa.”

Other groups included on the petition are: Allamakee County Protectors — Education Campaign, Center for Food Safety, Environmental Law & Policy Center, Environmental Working Group, Food & Water Watch, Iowa Alliance for Responsible Agriculture, Iowa Citizens for Community Improvement, Izaak Walton League of America — Iowa Division, Sierra Club Iowa Chapter, Socially Responsible Agriculture Project, Iowa Coldwater Conservancy, and Trout Unlimited — Iowa Driftless Chapter 717.

11 Iowans ask for tougher rules on CAFOs

Before approving revisions to Chapter 65 of Iowa’s Administrative Rules, the Iowa Environmental Protection Commission on Tuesday held a public hearing at which 11 people asked for tougher regulations on how developers build feeding operations and dispose of manure.

“Iowa has over 10,000 factory farms that contribute to over 750 impaired waterways,” Tom Mohan, of Cedar Rapids, said, referencing an often-repeated number from environmental activist organizations. “We believe clean water is a human right.”

Three people representing agricultural groups spoke in favor of the rules.

“The Iowa Cattlemen’s Association supports the rules you have before you,” said Eldon McAfee, an attorney with the Brick Gentry law firm and a former dairy farmer. He said the rules protect soil and water without infringing on farmers’ rights.

Commission Chair Harold Hommes asked DNR staff whether it was possible to change the proposed rules at Tuesday’s meeting. Staff said any major changes would start the rules review process over again.

Karst protections stripped from an early rules draft

The DNR’s first version of the Chapter 65 revision last fall included additional requirements for feeding operations in the karst terrain of northeast Iowa.

The version released in September said new CAFOs proposed to be built between 5 and 15 feet from karst would have been required to have a 5-foot continuous layer of low-permeability soil, nonsoluble bedrock or a 2-foot synthetic clay liner.

However, revisions sent to the EPC in November removed those additional separation requirements after the Governor’s Office told the DNR the proposed revision violated an executive order from Gov. Kim Reynolds that barred more restrictive rules.

One change that remained in the final version says the DNR will adopt a 100-year flood plain map so developers will know where feeding operations can’t be built.

The FFA chapter at Dayton High School in Oregon won a visit from agricultural influencer and TV and radio personality Rob Sharkey, better known by most as SharkFarmer.  

The contest was put on by the Virginia-based Propane Education & Research Council, and students could enter while at the 2023 National FFA Convention. The Dayton FFA Chapter stood out because of its dedication to agriculture education and community involvement, including the use of propane for its building heat, generator, forklift, and garden shed — an integral part of the school’s notable ag and horticulture program. There, students manage every step of the plant growth process, from seeding to sales, fostering leadership, and entrepreneurial skills.

Mitch Coleman, FFA sponsor for Dayton High School, plays a pivotal role in molding future agricultural leaders. His dedication to his students and demonstration of innovative solutions like propane have played a significant role in student successes. Under his guidance, students not only learn about animal science and farm management but also apply these lessons in real-world scenarios.

“I help create opportunities for students to apply what they learn so they will remember it forever,” said Coleman. “Wherever I take students becomes a new classroom — from the welding shop, greenhouse, or nature trail to county and state fairs, and the many FFA field trips we go on throughout the U.S. My goal is to help students find meaning and purpose in all they do.”

Rob Sharkey is an Illinois grain farmer, podcast and radio show host, and host of multiple TV shows on RFD-TV and PBS. His visit to Dayton High School offered students the opportunity to engage directly with a prominent voice in modern agriculture, and his insights and support helped inspire students to dream big and develop a broader perspective on agriculture challenges and innovations.

“By partnering with influential figures like Rob Sharkey and engaging with FFA chapters, we want to support the next generation of farmers by sparking interest and driving innovation within the farming community,” said Mike Newland, director of agriculture business development at PERC. “This contest is a way to honor those going above and beyond in their communities to ensure a vibrant future in agriculture, and we’re excited to see how propane continues to play a role in this. These students are the future of farming, and we’re here to help them thrive.”