Boldenone, boldione, and milk replacers in the diet of veal calves: the effects of phytosterol content on the urinary excretion of boldenone metabolites

Twenty-six veal calves were split into two groups and fed two milk replacers with a different content of phytosterols for 26 days; then, 14 calves (7 animals from each diet) were kept as controls and 12 calves (6 per diet) received daily, per os, a combination of 17beta-boldenone (17beta-Bol) and androsta-1,4-dien-3,17-dione (ADD) for 38 days. The urinary elimination of 17 alpha-/17beta-boldenone conjugates (17 alpha/beta-Bol) and androsta-1,4-dien-3,17-dione (ADD) was followed by liquid chromatography-tandem mass spectrometry from all of the animals until slaughtering. In urine from treated animals, 17 alpha-Bol concentrations, despite a great variability, were greater than 17beta-Bol, both detected always as conjugates. At days 1, 2, and 3, the mean urine concentration of 17 alpha-Bol was higher than 12 ng/mL. A remarkable decrease was observed during the following days, but the 17 alpha-Bol concentration was still higher than the attention level of 2 ng/mL in 58% of the samples; the concentration of 17beta-Bol was around the action level of 1 ng/mL; two days after treatment withdrawal, no 17beta-Bol was detected in the urine. In urine from control animals, the 17 alpha-Bol concentration was strictly related to the phytosterol content of the diet, while, in urine from treated animals, the much higher 17 alpha-Bol levels were not modified by the production from diet precursors. The results confirmed that a 17 alpha-Bol level higher than 2 ng/mL should be considered as evidence of suspected illegal treatment and that the urinary excretion of 17beta-Bol is due to exogenous administration of 17beta-Bol. The discontinuous rate of elimination of both 17 alpha- and 17beta-Bol, despite the daily administration of 17beta-Bol plus ADD, indicates the necessity for further research to detect other urinary boldenone metabolites to strength surveillance strategy.

Identification and quantification method of spiramycin and tylosin in feedingstuffs with HPLC-UV/DAD at 1 ppm level

The use of the two macrolides antibiotics Spiramycin (S) and Tylosin (T) as growth promoters in animal feeding has been recently withdrawn in the European Union due to a concern about the outbreaks of farmacoresistance fenomena as a possible hazard for humans. For feed additives monitoring purposes, an analytical method has been developed for their extraction, purification and identification in different animal feedingstuffs (pelleted beef, pig, poultry feeds and calves milk replacer) at a minimum performance required limit (MRPL) of 1 microg g(-1) (ppm). Such limit has been established according to the lowest dosage of additives still able to elicit an appreciable growth promoting effect. Blank feeds were spiked at two concentration levels, 1.0 and 2.5 ppm in six replicates. After methanolic extraction, samples were cleaned up on SPE CN columns and extracts analysed in HPLC-UV/DAD, using a gradient elution. Detection limits, calculated as the tree time mean noise of 20 blank feeds, were 176 and 118 ng g(-1) for S and T, respectively. Results show good repeatability (CV% not exceeding the value of 15) and mean recovery in the range of 99-74% and 81-53% for S and T, respectively, at 1 ppm. When the standards were injected up to 250 ng the chromatographic method can resolve the components of analytes (Spiramycin I, II and III; Tylosin A and B) but can not resolve the components on real feed samples at the spiked levels considered. For this reason the identification and quantification of analytes on matrix were carried out considering the main compound of the drugs (Spiramycin I and Tylosin A). As a verification, the overlapping of UV spectra in the range 220-350 nm between analytical standards and the compounds in the matrix were considered.

Traceability of inbred and crossbred Cinta Senese pigs by evaluating the oxidative stress

Previous studies on the oxidative stress in swine indicated a strong link between the values of reactive oxygen metabolites (ROMs), the subsequent antioxidant adaptive response (OXY) and the genetic selection. Such findings, mainly related to a cardiovascular inadequacy in lean, large muscle blocks and fast growing breeds, is associated with specific metabolic diseases such as porcine stress syndrome and mulberry heart disease. In this study, we investigated the oxidative stress parameters to trace the genetics of Cinta Senese (CS) pigs, a historical breed free-range reared in Siena countryside. Sera from CS (n = 24) and Large White x CS (LW x CS) (n = 24) groups around 120 kg body weight fed the same diet were sampled at slaughter. Sera from wild boars (WB) (n = 24) hunted in the same district were also considered. ROMs and OXY were evaluated in the three groups of swine. Significant differences by one-way anova (P < 0.05) between groups were found for both procedures. ROM levels were lower in WB (9.79 +/- 5.76 mm H2O2) and CS (18.02 +/- 7.42 mm H2O2), and highest in LW x CS (42.78 +/- 8.61 mm H2O2). OXY values ranged from 271.37 +/- 50.90 microm neutralized HOCl (WB) to 343.21 +/- 57.45 microm neutralized HOCl (LW x CS). Results indicated that the evaluation of the oxidative stress can effectively trace the CS pigs, thus aiding in preserving the overall specific traits of such a historical animal.

Synovial fluid as a matrix of selection in the detection of beta-adrenergic agonist drugs in carcases and fresh meat

Previous papers have supported the hypothesis that beta-agonist drugs could accumulate in those tissues with a high content of mucopolysaccharides. Based on our preliminary findings, between October and December 1993 we randomly sampled 534 samples of synovial fluids drawn from the knee joint of fresh carcasses. After a preliminary extraction able to break down the water domains of mucopolysaccharides and the interactions between the matrix and the drugs, samples were concentrated on diatomaceous earth and then screened on two different ELISA plates. We confirmed the structure of suspected fluids by GC-MS (HFBA derivatization), according to EC criteria. Of the 57 samples screened as positive (10.6% of the total), 51 (9.5%) were fully confirmed, while for six it was not possible to identify the drug. The results suggest that the analysis of synovial fluids is an adequate tool to monitor the misuse of beta-adrenergic drugs in animal production, especially when target organs such as liver and kidney are not available for sampling.