A preliminary investigation of the poultry body weight effect of essential oils in litter and residue in organ tissue of exposed chickens.

Abstract

The use of aromatic and flavor supplements, including herbs, is increasing in animal nutrition and treatment. The rising interest in these supplements stems from a trend towards healthy nutrition and natural raw materials in animal feed. The reduction or ban of antibiotics in animal nutrition has also boosted interest in supplements that replicate the growth-enhancing effects previously achieved with antibiotics. Alternative feed additives, such as essential oils, can be incorporated into litter. For example, eucalyptus leaves can be added as a natural herbicide. In this study, a litter additive containing carvacrol was prepared using plasti- cizers and potato starch. Carvacrol, an essential oil, possesses strong antifungal, antiviral, and antimicrobial properties, reducing parasites responsible for gastrointestinal diseases. The aim of this study was to evaluate the effect of the addition of carvacrol to litter on weight gain and evaluate the occurrence of residues in chicken tissues. A method for determining carvacrol in plasma, lung, muscles, and liver tissues was used to detect possible residues. The analysis of residues after 42 days of exposure to carvacrol in litter clearly indicated that the animals were in contact with the test substance. When analyzing the concentrations in individual tissues, it could be stated that the contact occurred through the lungs, because the highest concentrations of carvacrol residue was in this tissue. To the best of our knowledge, this is the first attempt to determine carvacrol residues in poultry tissue after exposure to the substance contained in litter, and these are the first data to confirm its residues after such exposure.