Litter amendments differentially modulate trace metal concentrations and norepinephrine in the broiler chicken gut

Authors: Lyte, Joshua - Josh; Caputi, Valentina; Anderson, Kelsey; DANIELS, KARRIE - Iowa State University; LYTE, MARK - Iowa State University; Moore, Philip

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 5/24/2023
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Objective: Liquid and dry acids, such as aluminum sulfate (alum), are often added to poultry litter as amendments to reduce ammonia emissions. Although chickens regularly consume their litter, it is unknown if litter amendments impact trace metal concentrations in the gut lumen that are relevant in host-microbe interactions. It is critical to understand if litter amendments affect intestinal homeostasis of metal concentrations that are required by bacterial pathogens for growth. The present study sought to determine whether different litter amendments affect gut luminal concentrations of aluminum, transition metals, as well as norepinephrine, a host neurochemical demonstrated to mediate bacterial iron acquisition. Experimental design: Male broiler chicks were randomly divided into pens containing poultry litter with no litter amendment (control) or treated with either 1) 200lbs alum/1,000 ft2, 2) 200lbs alum/1,000 ft2 + 5lbs Ca nanoparticles/1,000ft2, 3) 200lbs NaHSO4/1,000ft2, 4) 200lbs alum mud litter amendment (AMLA)/1,000 ft2, or 5) 200lbs NaHSO4/1,000 ft2 + 5lbs Ca nanoparticles/1,000 ft2 as litter amendments. All birds were maintained under otherwise standard environmental conditions. At 3 and 6 wks of age, chickens were euthanized for tissue collection (n=12 chickens/group/age). Methods: Total metal concentrations in ileal contents were determined using inductively coupled plasma optical emission spectroscopy. Norepinephrine concentrations in ileal tissue were determined using ultra-high performance liquid chromatography with electrochemical detection. Statement of statistical analyses: Metal and norepinephrine datasets were analyzed using two-way ANOVA with Tukey posthoc test. Results: At 3 wks of age aluminum concentrations of ileal contents was elevated (p<0.05) in birds raised on alum amendment compared to control. Iron was higher (p<0.05) in the alum group at 6 wks of age compared to control group. Copper, manganese, nickel, and zinc concentrations were not (p>0.05) different compared to respective control group at either age. Litter amendments altered (p<0.05) norepinephrine concentrations in ileal tissue of 6 wks of age but not 3 wks of age birds compared to respective controls. At 6 wks of age, alum and AMLA groups had greater (p<0.05) ileal tissue norepinephrine concentrations compared to control group. Conclusions: Although litter amendments like alum do not affect the aluminum content of poultry meat, the aluminum, iron, and norepinephrine concentrations in the broiler chicken ileum were affected by type of litter amendment. These findings warrant future studies that seek to leverage environmental drivers of metal homeostasis in the chicken gut to potentially modulate microbial growth.