Approximately 30 distinct Mycoplasma species have been isolated from cattle, but only a few are pathogenic and can cause serious respiratory diseases. Consequently, this study aimed to identify Mycoplasma spp. infections in cattle with bovine respiratory disease (BRD), considering factors such as animal demographics, concurrent infections with other pathogens, post-mortem clinical findings and histological examinations, and seasonality. A total of 326 samples were collected from 322 cattle that had died from BRD in Northwestern Italy. A total of 54 animals (16.8%) tested positive for Mycoplasma spp., and Mycoplasma bovis (n = 22, 40.7%) and Mycoplasma dispar (n = 13, 24.1%) were the most frequently detected species among the examined cattle. Among positive cattle, those aged five months or younger were approximately five times more likely to be infected by Mycoplasma dispar than by Mycoplasma bovis compared to those older than five months (proportional incidence ratio: 5.1, 95% CI 1.2–21.2). The main bacterial pathogens identified in cattle exhibiting co-infection was Pasteurella multocida, whereas the main viral pathogens were BRSV and BoHV-1. Histopathological investigations predominantly revealed catarrhal bronchopneumonia or purulent catarrhal bronchopneumonia among the examined cattle. Finally, Mycoplasma hyopharyngis, a species isolated from the pharyngeal and nasal cavities of pigs so far, was detected for the first time in the pneumonic lung of a bovine infected with BRD. Further investigations are necessary to thoroughly characterize its host range and pathogenic potential.

Corticosteroids such as Dexamethasone (DEX) are commonly licensed for therapy in meat animals due to their known pharmacological properties. However, their misuse aimed to achieve anabolic effects is often found by National Residues Control Plans. The setup of a complementary “biomarker based” methods to unveil such illicit practices is encouraged by current European legislation. In this study, the combined use of molecular and histological quantitative techniques was applied on formalin fixed paraffin embedded (FFPE) muscle samples to assess the effects of illicit DEX treatment on veal calves. A PCR array, including 28 transcriptional biomarkers related to DEX exposure, was combined with a histochemical analysis of muscle fiber. An analysis based on unsupervised (PCA) and supervised (PLS-DA and Kohonen’s SOM) methods, was applied in order to define multivariate models able to classify animals suspected of illicit treatment by DEX. According to the conventional univariate approach, a not-significant reduction in type I fibres was recorded in the DEX-treated group, and only 12 out of 28 targeted genes maintained their expected differential expression, confirming the technical limitations of a quantitative analysis on FFPE samples. However, the multivariate models developed highlighted the possibility to establish complementary screening strategies, particularly when based on transcriptional biomarkers characterised by low expression profiles.

The Histological Control Plan has been introduced in Italy in 2008 as an indirect monitoring tool of illicit administration of sexual hormones and corticosteroids in bovine. Analysis of 2008-2016 results permitted to draw a new plan targeting risk category. This work presents the results of the histopathological monitoring plan that was carried out from 2017 to 2019. The overall prevalence of samples suspected of treatment with corticosteroid was 11.3% [95% confidence interval (CI) 6.6-17.8] in 2017; 10.2% (95% CI 6.6-16.9) in 2018 and 8.9% (95% CI 4.6-15.4) in 2019. The overall prevalence of samples suspected of treatment with sexual hormones was 2.3 % (95% CI 0.5-6.6) in 2017; 6.2% (95% CI 2.7-11.8) in 2018 and 12.4% (95% CI 7.4- 19.1) in 2019. Although not targeting and measuring specific molecules, this strategy allows to verify the trend of illicit treatments and identify farms to be submitted to further check.

Background Sex steroids administration in meat producing animals is forbidden within the EU to preserve consumers’ safety, but continuous monitoring to identify resurgence of their misuse is needed. Among biomarkers related to sex steroids abuse in veal calves the regucalcin (RGN) mRNA perturbations in testis have been described in RNAlater samples. To setup novel diagnostic method, to update current tests available in National Residue Control Plans (NRCPs) and in legal dispute when illicit practices on farm animals are suspected, the reliability of RGN profiling was assessed by histological and molecular techniques. Methods Formalin fixed paraffin embedded (FFPE) testis samples, chosen being the most effective preservation strategy adopted by histological NRCPs and allowing easier retrospective analysis if required by legal disputes, were analyzed from veal calves treated with nandrolone, 17β-estradiol and a cocktail of the two hormones. RGN levels were determined by quantitative Real Time PCR and Immunohistochemistry assays. Test performances were assessed and compared by multiple ROC curves. Results Both tests resulted sensitive and specific, allowing to enrich, in future field investigation, novel integrated diagnostic protocols needed to unveil sex steroid abuse. Discussion Developed RT-qPCR and IHC methods confirmed RGN as a useful and robust biomarker to detect illegal administration of sex steroid hormones in veal calves. The developed methods, successfully applied to ten years old FFPE blocks, could allow both retrospective analysis, when supplementary investigations are requested by authorities, and future implementation of current NRCPs.

The use of anabolic–androgenic steroids (AASs) as growth promoters in farm animals is banned in the European Union, representing both an illicit practice and a risk for consumer health. However, these compounds are still illegally administered, often in the form of synthetic esters. This work aimed to characterize significant coding RNA perturbations related to the illicit administration of testosterone and nandrolone esters in fattening pigs. A total of 27 clinically healthy 90-day-old pigs were randomly assigned to test and control groups. Nine animals were treated with testosterone esters (Sustanon^®) and other nine with nandrolone esters (Myodine^®). At the end of the trial, liver samples were collected and analyzed using RNAseq, allowing the identification of 491 differentially expressed genes (DEGs). The transcriptional signature was further characterized by a smaller sub-cluster of 143 DEGs, from which a selection of 16 genes was made. The qPCR analysis confirmed that the identified cluster could still give good discrimination between untreated gilt and barrows compared to the relative testosterone-treated counterparts. A conclusive field survey on 67 liver samples collected from pigs of different breeds and weight categories confirmed, in agreement with testosterone residue profiles, the specificity of selected transcriptional biomarkers, showing their potential applications for screening purposes when AAS treatment is suspected, allowing to focus further investigations of competent authorities and confirmatory analysis where needed.

Among forbidden substances included in the European Union legislation, endogenous steroids constitute a challenge in the framework of veterinary Official Monitoring Plans. They can be naturally present in body fluids at variable levels depending on the species, sex and age of the animals. Considering the significant advances achieved in breeding conditions and in the selection of producing traits in meat cattle, the aim of this study was to verify by analytical method, in veal calves housed under controlled conditions, if the level of natural steroids hormones assumed as physiological are still actual. The second aim of the study was to verify if the normal histological pattern of growth promoters in target organs is influenced accordingly. Bovine male sex organs are currently analysed in the frame of the Italian histological plan to monitor illicit treatments trend, highlighting microscopic, induced alterations. The levels of 17β-estradiol and progesterone residues resulted under the Limit of Quantitation of the approved official methods and the level of testosterone resulted below the level stated in the Italian Ministerial Decree in force. Male target organs appeared within the limits of the standard histological features.