Identification by volatolomics of hydrocarbon, oxygenated, sulfur and aromatic markers of livestock exposure to α-hexabromocyclododecane.

Volatile organic compounds (VOC)-based metabolomics, or volatolomics, was investigated for revealing livestock exposure to chemical contamination. Three farm animals, namely laying hens, broilers, and pigs, were experimentally exposed to 5 or 50 ng α-HBCDD g-1 feed. Liver and egg yolk for hens were analysed by headspace-SPME-GC-MS to reveal candidate markers of the livestock exposure to α-HBCDD. For hens, 2-butanol was found as marker in egg. In liver, twelve VOCs were highlighted as markers, with three aromatic VOCs - styrene, o-xylene, α-methylstyrene - highlighted for the two α-HBCDD doses. For broilers, six markers were revealed, with interestingly, styrene and phenol which were also found as markers in hen liver. For pigs, ten markers were revealed and the seven tentatively identified markers were oxygenated and sulfur VOCs. The candidate markers tentatively identified were discussed in light of previous volatolomics data, in particular from a γ-HBCDD exposure of laying hens.

A PBPK model to study the transfer of α-hexabromocyclododecane (α-HBCDD) to tissues of fast- and slow-growing broilers.

A physiologically based pharmacokinetic (PBPK) model was developed to investigate the production-specific factors involved in the transfer of α-hexabromocyclododecane (α-HBCDD) to broiler meat. The model describes growth and lipid deposition in tissues of fast- (FG) and slow- (SG) growing broilers from hatching to slaughter and simulates the exposure through the ingestion of contaminated feed or expanded polystyrene insulation material. Growth parameters were obtained from the literature while parameters relative to uptake, distribution, and elimination of α-HBCDD were adjusted using results of a previous experiment involving broilers exposed through feed throughout the rearing period or allowed to depurate before slaughter. The model was used to compare the two main edible tissues, breast and leg meat, as well as skin, and to investigate the variability within strain. Between strains and within strain, α-HBCDD assimilation efficiency (AE) is higher when the animals are slaughtered young or heavy. However, increasing slaughter age will lower α-HBCDD concentration in tissues, due to dilution. Based on fresh weight, the concentration of α-HBCDD in breast muscles and skin tends to be lower in SG than in FG broilers (-30 to +10%), while it is 10% to 80% higher in leg muscles. Compared to breast muscles, consuming leg muscles would elicit an exposure 9 and 16 times higher in FG and SG broilers, respectively. The consumption of skin together with muscles would multiply the exposure by up to 36 times compared to breast muscle alone. In case of acute exposure, the α-HBCDD concentration in tissues increased sharply, all the more since the animals are lighter in weight, and then decreased rapidly. In FG broilers, dilution through growth contributed for up to 37%, 28% and 97% to the decontamination of breast muscles, leg muscles and skin, respectively, depending on the duration of depuration before slaughter.

Classification of trace elements in tissues from organic and conventional French pig production.

This study assesses the impact of the farming system on the levels of copper, zinc, arsenic, cadmium, lead and mercury in pig tissues from three types of production (Organic (n = 28), Label Rouge (n = 12) and Conventional (n = 30)) randomly sampled in different slaughterhouses. All the concentrations were below regulatory limits. In muscles, Cu, Zn and As were measured at slightly higher levels in organic samples but no differences between organic and Label Rouge was observed. Livers from conventional and Label Rouge pig farms exhibited higher Zn and Cd contents than the organic ones, probably due to different practice in zinc or phytase supplementation of fattening diets. Principal component analysis indicated a correlation between Cu and As concentrations in liver and carcass weight, and between Zn and Cd liver levels and lean meat percentage. The linear discriminant analysis succeeded in predicting the farming process on the basis of the lean meat percentage and the liver Cd level.

Micropollutants and chemical residues in organic and conventional meat.

The chemical contamination levels of both conventional and organic meats were assessed. The objective was to provide occurrence data in a context of chronic exposure. Environmental contaminants (17 polychlorinated dibenzodioxins/dibenzofurans, 18 polychlorinated biphenyls (PCBs), 3 hexabromocyclododecane (HBCD) isomers, 6 mycotoxins, 6 inorganic compounds) together with chemical residues arising from production inputs (75 antimicrobials, 10 coccidiostats and 121 pesticides) have been selected as relevant compounds. A dedicated sampling strategy, representative of the French production allowed quantification of a large sample set (n=266) including both conventional (n=139) and organic (n=127) raw meat from three animal species (bovine, porcine, poultry). While contamination levels below regulatory limits were measured in all the samples, significant differences were observed between both species and types of farming. Several environmental contaminants (Dioxins, PCBs, HBCD, Zn, Cu, Cd, Pb, As) were measured at significantly higher levels in organic samples.

Determination by echography of uterine changes around puberty in gilts and evaluation of a diagnosis of puberty.

Three experiments were carried out to evaluate the use of ultrasonography in assessing the onset of puberty in gilts. In experiment 1, gilts (n = 17) were scanned 3 times per week beginning at 133 and continuing until 187 days of age. The ultrasonic appearance of the uterus was described, quantified and compared with the reproductive status observed at slaughter. The quantification of the pictures showed a different correlation in time for infantile, impubertal, prepubertal and pubertal stages. For pubertal females, "uterine area" increased at around 180 days of age, well-defined sections of the uterine horns appeared 3 +/- 0.5 days before puberty. In infantile and impubertal gilts during the same period of age, uterine images remained dark and homogeneous; no significant change in the "uterine area" was observed. This difference in images allowed an evaluation of the diagnosis of puberty. In experiment 2, the gilts (n = 123) were scanned, the result was verified at slaughter the day after by examination of the genital tract. The uterine weight of the gilts that had reached a prepubertal or pubertal stage was significantly greater (P = 0.0001) than that in impubertal gilts. The sensitivity and the specificity of the diagnosis were 91.9% and 96.5% respectively. Experiment 3 was performed on a farm and echographic examinations were carried out one and five days after gilts (n = 117) arrived at the piggery. Oestrus detection or blood sampling for progesterone determinations were used as tools to determine the reproductive status. The sensitivity and the specificity of the diagnosis were 98.9% and 100% respectively. This diagnosis of puberty is thus accurate.