Poultry Science Researchers Fine Tune Chicken Sprinkler Technology

Yi Liang

Associate Professor of Biological and Agricultural Engineering

Contact Yi Liang

Walter Bottje

Experiment Station Poultry Science Physiologist

Contact Walter Bottje

Sami Dridi

Professor of Poultry Science

Contact Sami Dridi

The Problem

Heat stress is one of the most challenging stressors to poultry production. Evaporative cooling cell pad systems are the standard for keeping birds cool, but they use a substantial amount of water and have other shortcomings. For example, these moisture-rich systems saturate a barn air with a relative humidity greater than 70 percent. For a bird, this is counterproductive to cooling itself by breathing.

Previous studies from 2009-2011 showed that sprinkler cooling systems, which use substantially less water, are a viable alternative to cooling cell pad systems. Sprinkler systems drop a relatively small amount of water directly on the birds to produce a windchill effect when exhaust fans pull air through the building. On average, 67 percent less water was used by sprinkler cooling systems than the cool-cell pad systems during summer in that study.

Since water is a crucial and substantial component of poultry production, not only for bird consumption but also to alleviate heat stress, sprinklers show promise as an effective cooling system that also reduces water consumption. The next step is to optimize the use of sprinklers for greater cooling and water-use efficiency.

Water conservation is also of interest due to a potential decrease in available water resources. According to the National Oceanic and Atmospheric Administration, in the United States and around the world, water security is “increasingly in jeopardy.”Expected climate change impacts on water vary regionally and will include changing sea levels, increased frequency of heavy downpours, changes in water quality, and longer, more intense periods of drought, NOAA states at its Water Initiative Vision and Five-Year Plan website.

The Work

Studies by the University of Arkansas System Division of Agriculture have been conducted on chicken sprinklers since 1995. The most recent experiment station study on chicken sprinklers was carried out in 2021 at two commercial broiler houses measuring about 40-by-400 feet at the Applied Broiler Research Unit at the Savoy Research Complex.

Yi Liang, associate professor of biological and agricultural engineering for the Division of Agriculture, collaborated with Tom Tabler at Mississippi State University. They investigated the water conservation aspect of chicken sprinklers as part of a National Institute of Food and Agriculture (NIFA) Sustainable Agriculture Systems grant awarded in 2019. The $9.95 million grant is directed by Walter Bottje, an experiment station poultry science physiologist, and co-directed by poultry science professor Sami Dridi.

In 2021, Liang and Tabler evaluated proper management of the cooling-cell temperature set points in houses with sprinkler systems to optimize cooling performance. Two flocks were evaluated — one in spring and the other in summer.

The Results

The collective chicken sprinkler research shows that sprinklers make chickens get up and move around more. This helps release trapped body heat and encourages visits to the feeders and drinkers.

Tests showed that sprinklers should be activated before the poultry house temperature approaches 90 degrees Fahrenheit. The set point of a cooling-cell system should be about 21 degrees above the house set point to allow sprinkler activation under a drier thermal condition, Liang noted in her report.

In the 2021 study, the feed conversion rate was 1.78 in the spring flock and 1.83 in the summer flock with a “livability percentage” at 94.66 percent in the spring flock and 95.28 percent in the summer flock. Live market weights were comparable in the 2021 study with 9.24 pounds at 55 days in the spring flock and 9.37 pounds at 57 days in the summer flock.

There was also no significant difference in chicken litter quality under the sprinkler systems due to a less humid environment. Consistent with previous studies conducted at the Savoy Unit between 2009-2011, sprinklers houses finished with chicken litter moisture levels of about 34 percent, about 2 percent lower than litter found in cooling-cell houses with higher humidity levels.

Finding the best conditions in which to utilize sprinklers versus the cooling-cell systems will help producers maximize water conservation while maintaining bird thermal comfort.

The Value

As pointed out by Dridi in a 2020 report published in Frontiers in Veterinary Science, sprinkler technology improves broiler production sustainability and provides significant water savings.

Dridi noted in a 2017 article at PubMed.gov that surface wetting by sprinklers prevents heat stress from increasing body temperature and plasma corticosterone levels. At molecular levels, Dridi explains, surface wetting “blocks the activation of hypothalamic heat shock protein and adenosine monophosphate-activated protein induced by heat stress” and “significantly modulates the expression of feeding-related hypothalamic neuropeptides (agouti-related protein, proopiomelanocortin, orexin, orexin receptor, and leptin receptor).”

“Water conservation is a major emphasis for the poultry industry today as it strives to become more sustainable and lessen its carbon footprint,” Tabler writes. “Climate change and heat stress are challenges to these sustainability efforts. Cool-cell systems, while effective, require large amounts of water and reduce the bird’s ability to cool itself through respiratory evaporation. However, sprinkler systems offer cooling water conservation of over 50 percent compared to a cool-cell system while maintaining production without sacrificing flock performance.”

Funding

This research was funded in part by the National Institute of Food and Agriculture, part of the U.S. Department of Agriculture. Additional support was provided by Weeden Environments of Woodstock, Ontario, Canada.

A focus of the $9.95 million grant, “Empowering US Broiler Production for Transformation and Sustainability,” is on improving water use efficiency either at the bird level or by the housing systems. Funds from the grant help further optimize the sprinkler systems for broiler production.

About the Researcher