Long-term administration of low doses of mycotoxins in poultry. 1. Residues of ochratoxin A in broilers and laying hens

A Study of Carry-Over and Histopathological Effects after Chronic Dietary Intake of Citrinin in Pigs, Broiler Chickens and Laying Hens

Citrinin (CIT) is a polyketide mycotoxin occurring in a variety of food and feedstuff, among which cereal grains are the most important contaminated source. Pigs and poultry are important livestock animals frequently exposed to mycotoxins, including CIT. Concerns are rising related to the toxic, and especially the potential nephrotoxic, properties of CIT. The purpose of this study was to clarify the histopathological effects on kidneys, liver, jejunum and duodenum of pigs, broiler chickens and laying hens receiving CIT contaminated feed. During 3 weeks, pigs (n = 16) were exposed to feed containing 1 mg CIT/kg feed or to control feed (n = 4), while 2 groups of broiler chickens and laying hens (n = 8 per group) received 0.1 mg CIT/kg feed (lower dose group) and 3 or 3.5 mg CIT/kg feed (higher dose group), respectively, or control feed (n = 4). CIT concentrations were quantified in plasma, kidneys, liver, muscle and eggs using a validated ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method. Kidneys, liver, duodenum and jejunum were evaluated histologically using light microscopy, while the kidneys were further examined using transmission electron microscopy (TEM). Histopathology did not reveal major abnormalities at the given contamination levels. However, a significant increase of swollen and degenerated mitochondria in renal cortical cells from all test groups were observed (p < 0.05). These observations could be related to oxidative stress, which is the major mechanism of CIT toxicity. Residues of CIT were detected in all collected tissues, except for muscle and egg white from layers in the lowest dose group, and egg white from layers in the highest dose group. CIT concentrations in plasma ranged between 0.1 (laying hens in lower dose group) and 20.8 ng/mL (pigs). In tissues, CIT concentrations ranged from 0.6 (muscle) to 20.3 µg/kg (liver) in pigs, while concentrations in chickens ranged from 0.1 (muscle) to 70.2 µg/kg (liver). Carry-over ratios from feed to edible tissues were between 0.1 and 2% in pigs, and between 0.1 and 6.9% in chickens, suggesting a low contribution of pig and poultry tissue-derived products towards the total dietary CIT intake for humans.

Estimation of ochratoxin A in poultry feed and its ingredients with special reference to temperature conditions

1. The present study was designed to analyse ochratoxin A (OTA) in poultry feed samples (mixed types) along with different poultry feed ingredients collected from different farms and market of Lahore, Pakistan. 2. The whole year (2012-2013) was divided into three sub-periods depending upon environmental conditions, that is, July-October (hot and humid), November-February (winter) and March-June (moderate). During each sub-period 120 samples were collected for each feed and each ingredient constituting a total of 840 samples (120x7 of feed and feed ingredients in each sub-period). 3. The results of this study indicated that the incidence of OTA-positive samples was highest in July-October followed by that during March-June while the incidence was minimum during November-February. Similarly, the largest number of samples was below the maximum tolerable level (MTL) during November-February followed by March-June while the least number of samples was below MTL during hot weather (July-October). 4. This is the first elaborative study regarding the levels of OTA in poultry feed and its ingredients collected from Lahore, Pakistan.

A survey of spontaneous occurrence of ochratoxin A residues in chicken tissues and concurrence with histopathological changes in liver and kidneys

Toxicological and histopathological investigations of tissues of commercially slaughtered chickens were carried out to provide a preliminary evaluation of the incidence of occurrence of ochratoxin A (OTA) in chicken sold in Serbian retail market. In addition, the etiology of nephropathies of these chickens was elucidated. The majority of these tissue samples were not found to contain measurable amounts of OTA. Moreover, the OTA levels found in analyzed tissues were generally low and there was no positive correlation between the presence of OTA and the frequency of histopathological changes. Histopathological changes such as degenerative changes in the kidneys and liver differed from the classical description of the mycotoxic nephropathy, indicating that the chicken nephropathy observed in Serbia may have a multitoxic etiology with possible synergistic effect between microorganisms and natural toxins, usually present in low concentrations. The low OTA results also suggested that chicken meat available in the retail market in Serbia are unlikely to pose any significant adverse health risk to the consumers with respect to OTA toxicity.

An integrated sample preparation to determine coccidiostats and emergingFusarium-mycotoxins in various poultry tissues with LC-MS/MS

The usefulness of an existing sample preparation technique used for ionophoric coccidiostats (lasalocid, monensin, salinomycin and narasin) was applied in the analysis of emerging Fusarium-mycotoxins beauvericin (BEA) and enniatins (ENNs) in poultry tissues (liver and meat). Also, maduramicin and liver as a new sample matrix was introduced. The developed methods were validated and applied for the determination of coccidiostats and BEA/ENNs in Finnish poultry tissues in 2004-2005. The validation parameters demonstrated that the integrated sample preparation technique is applicable to the parallel determination of these contaminants in poultry tissues. Of the samples analysed (276 meat and 43 liver), only trace levels of LAS, MON, SAL, NAR and MAD were detected in 7, 3, 5, 6 and 4% of the samples, respectively. Interestingly, for the first time, traces of BEA and ENNs could also be detected in animal tissues. BEA and ENNs A, A1, B and B1 were found in 2, 0.3, 0.6, 4 and 3% of the samples, respectively. The simultaneous presence of coccidiostats and mycotoxins was detected in three turkey samples in 2004.

Tissue distribution of ochratoxin A as determined by HPLC and ELISA and histopathological effects in chickens

Ochratoxin A is a common feed contaminant, which may impair animal health and may lead to residues in edible tissues of slaughter animals. To simulate field conditions, broiler chicks were exposed to a total of 0.5 mg ochratoxin A per week for each of 4 weeks. Plasma toxin levels and tissue residues were measured by high-performance liquid chromatography (HPLC) and microplate enzyme-linked immunosorbent assay (ELISA). Results indicate an accumulation in plasma and wide distribution into all organs, with high levels in the liver and the kidney. Microscopical changes that could primarily be associated with toxin exposure were glomerulonephrosis, tubulonephrosis, focal tubular epithelial cell proliferation and multiple, adenoma-like structures in the renal parenchyma. The HPLC and ELISA methods gave similar results for both tissue distribution and depletion. Differences in absolute tissue toxin concentrations obtained by the two methods might be attributed to the different extraction and clean-up procedures, along with antibody specificity. The findings indicate that the dose applied causes subclinical tissue lesions and measurable tissue residues.

Study on effects of feeding laying hens on separate mycotoxins (aflatoxins, patulin, or citrinin)-contaminated diets on the egg quality and tissue constituents

Four groups (each of 8 laying hens plus one cock) were offered commercial laying mash contaminated with 100 ppb of aflatoxins, citrinin, patulin or uncontaminated (control) for 6 weeks. The mycotoxin-contaminated diets led to some significant changes in egg characteristics and composition such as ash and calcium contents of the egg shell. The noticeable changes including also the relative weights of adrenal glands. Blood profile reflected too alterations (P greater than 0.05) in urea content and activity of both glutamic oxaloacetic transaminase and alkaline phosphatase as well. The mycotoxins affected significantly moisture and fat contents of the red muscle and protein content, texture and percentage of lean meat in both types of muscles (red and white). Patulin toxicosis was responsible for the strongest alterations in moisture, fat and vitamin A contents of the laying hen's liver and for the lowest calcium content of egg shell besides the shape alteration of the eggs. Laying hens fed on aflatoxin-contaminated diet produced hatched chicks with higher weight (P less than or equal to 0.05) than those from the controls. Citrinin residues were 10 ppb in the fresh muscles and egg yolk and 6 ppb in egg white.