Aflatoxin M1 is a highly toxic 4-hydroxylated metabolite of aflatoxins B1 and B2. It is one of the most potent hepatocarcinogens, mutagens, teratogens and immunosuppressors. Feed is often contaminated with aflatoxigenic moulds and aflatoxins with a high possibility of contaminating milk and dairy products with aflatoxin M1. Samples of artificially contaminated milk were exposed to the effects of physical conditions (temperature of -18oC and for microwaves in a microwave oven), time (during the period from 1 to 12 months) and a combination of the above mentioned conditions. Following this, levels of aflatoxin M1 degradation were established by using the ELISA method. An insignificant decrease in concentration of toxin was observed which indicates that a temperature of -18°C does not significantly influence the concentration of aflatoxin M1 in the artificially contaminated milk. At the same time, treatment of milk with microwaves in a microwave oven showed an insignificant influence on the percentage of aflatoxin M1 absorbance.

Nitrofurans are synthetic broad-spectrum antimicobial agents that are often used in commercial animal production because of their excellent antibacterial and pharmacokinetic properties. However, nitrofurans and their metabolites have been shown to have potentially carcinogenic and mutagenic characteristics which has led to a ban on the use of nitrofurans in preventive and therapeutic treatment of animals used for food production. Metabolites of nitrofurans that can be determined after their application are: a metabolite of furazolidone, furaltadone metabolite, a metabolite of nitrofurantoin and nitrofurazone metabolite. The presence of residues of nitrofuran antibiotics in meat, fish and shrimps, and milk and eggs originating from countries outside the European Union is monitored and recorded by the RASFF system of the European Union. Furthermore, since nitrofurans are used in some countries as prophylactic agents and growth promoters, it is necessary to carry out constant control of various types of food of animal origin, in order to reduce to the minimum potential carcinogenic and mutagenic effects of these supstances for the health of consumers. In Bosnia and Herzegovina, there is no permanent control of nitrofurans in food of animal origin. The provisions of the „Regulation on the maximum allowable amounts of veterinary drugs and pesticides in products of animal origin", published in the Official Gazette of Bosnia and Herzegovina state the prohibiting of the use of certain veterinary drugs in animals intended for human consumption, including nitrofurans. The European Union has established the minimum required limit (MRLP) for performance which is 1 μg/kg of nitrofurans for edible tissues of animal origin. Taking all this into account, methods for nitrofurans detection should be accreditated and validated, both for screening and confirmatory methods, and further research into the presence of nitrofurans in food of animal origin in Bosnia and Herzegovina should be performed.

Serotonin or 5-hydroxytryptamine (5-HT), is a monoamine neurotransmitter synthesised from L-tryptophan in serotonergic neurons and enterochromaffin cells of the gastrointestinal tract. This neurotransmitter is widely distributed in the animal and plant kingdom and regulates some central and peripheral functions through several types of specific serotonergic (5-HT) receptors. Since it is known that the effect of serotonin, especially in pathological conditions, is very important, we believe that determining the types of receptors for this substance would make it possible to use their agonist or antagonists, which would undoubtedly enhance the pharmacotherapy of functional disruption of the small intestine in broilers. Investigations were carried out on isolated smooth muscle strips of the circular and longitudinal layer of the broiler small intestine (strip dimension 3-4 mm x 2 cm). The muscle strips were placed in an isolated organ bath. The mechanical activity of the preparations was recorded via an isotonic force transducer coupled to a pen recorder. This was done following the addition of serotonin (nonselective 5-HT agonist), 8-OH-DPAT (selective 5-HT1A agonist) and spiroxatrin (selective 5-HT1A antagonist). The sensitivity of the tissues to acetylcholine was tested before starting the experiments. Using the obtained results, it can be concluded that 5HT1A type receptors are present in smooth muscles of the broiler small intestine, duodenum and ileum, especially in the longitudinal smooth muscle layer which reacted with contractions even to low serotonin concentration (10-6), but not in the jejunum.

Histamine is a biologically active amine (biogenic amine) that has a broad spectra of physiologic and pathologic reactions in the organism. Its effects are shown through 4 types of specific receptors (H1, H2, H3 and H4). Histamine is one of the main causes of intestine disorders and the occurrence of diarrhea, both of which are very common in broilers. Whilst there is no information in scientific literature about the presence of histaminic receptors in smooth muscles of the small intestine wall of broilers (duodenum, jejunum and ileum), we tried to determine their presence, distribution and type in this kind of muscles. Investigations were carried out on isolated smooth muscles of the circular and longitudinal layer of the broiler small intestine (strip dimension 3-4 mm x 2 cm). The muscle strip was then placed in an isolated organ bath and the contractions obtained were registered with isometric transducers on a two-channel printer. This was done following the addition of histamine, betahistine (H1 agonist), and mepiramine (H1 antagonist). Muscle vitality was checked by adding acethylcholine chloride. Using the obtained results, it can be concluded that H1 types of histaminergic receptors are present in smooth muscles of the small intestine of broilers. .