Submitted to: Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 10, 1997
Publication Date: N/A
Interpretive Summary: Mycotoxins are poisons produced by molds that sometimes grow on grains or on poultry and livestock feeds. Poultry are sensitive to some mycotoxins that have caused costly production losses. Cyclopiazonic acid (CPA) is a mycotoxin that has been shown to be toxic to several species of animals. Practical and cost effective methods to detoxify mycotoxins such as CPA are currently not available. In recent tests, we have shown the effectiveness of selected clay materials (adsorbents) to bind CPA in test tubes. The present research was conducted to evaluate the effectiveness of three clay materials for protection against the toxicity of CPA in broiler chicks. The results show that CPA was moderately toxic to broiler chicks and none of the clay materials were effective in decreasing the growth reduction caused by CPA. These findings are important because they show that predictions about the ability of adsorbents to prevent the toxic effects of mycotoxins in live animals should be approached with caution, and should be confirmed by testing in live animals. Particular attention should be given to the potential for interactions with nutrients needed by the animals for proper health and growth.
Previous studies with cyclopiazonic acid (CPA) have indicated that this mycotoxin strongly adsorbs onto the surface of a naturally acidic phyllosilicate clay (AC). The objective of this study was to determine whether AC (and similar adsorbents) could protect against the toxicity of CPA in vivo. Acidic phyllosilicate clay, neutral phyllosilicate clay (NC, or hydrated sodium calcium aluminosilicate), and a common zeolite (CZ, or clinoptilolite) were evaluated. One-day-old broiler chicks consumed diets containing 0 or 45 mg/kg CPA alone or in combination with 1% AC, NC, or CZ ad libitum from Day 1 to 21. Body weight, feed consumption, feed:gain, hematology, serum biochemical values, and enzyme activities were evaluated. Compared to control, CPA alone reduced body weight at Day 21 by a total of 26% and resulted in a significantly higher feed:gain ratio. Toxicity of CPA was also expressed through increased relative weights of kidney, proventriculus, and gizzard. There were some alterations in hematology, serum biochemical values, and enzyme activities. Dietary adsorbents did not effectively diminish the growth-inhibitory effects of CPA or the increased weights of organs, although there was some protection from hematological, serum biochemical, and enzymatic changes produced by CPA. The results of this study suggest that in vitro binding of CPA to clay does not accurately forecast its efficacy in vivo; which may be related to differences in clay binding capacity and ligand selectivity for CPA in vitro vs in vivo. Predictions about the ability of inorganic adsorbents to protect chickens from the adverse effects of mycotoxins should be approached with caution and should be confirmed in vivo, paying particular attention to the potential for nutrient interactions.