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Simple Summary: Animal welfare assessment is crucial for farm animal health and productivity. New standardized biomarkers are needed to gain a complete picture of the ethological, physiological, and psychological needs of animals. With this study, we wanted to investigate potential biomarkers for measuring the physical and mental health of dairy cows. Since the stress induced by housing conditions can give rise to multisystem alterations, we compared the effects of three different farming systems. Plasma levels of hematological and inflammatory markers and more than 130 metabolites were investigated by magnetic bead panel multiplex assay and mass spectrometry assay, in addition to brain and plasma levels of brain-derived neurotrophic factor (BDNF), a neurotrophin involved in neuroplasticity and synaptogenesis, and indoleamine 2,3-dioxygenase, an enzyme whose dysregulated activity in humans has been correlated with mood disorders. Our findings suggest that because BDNF level, kynurenine pathway, and lipid-profiling alterations may modulate a depression-like state in tie-stall cattle, they may be potential biomarkers for monitoring dairy cattle welfare. Complete animal welfare evaluation in intensive farming is challenging. With this study, we investigate new biomarkers for animal physical and mental health by comparing plasma expression of biochemical indicators in dairy cows reared in three different systems: (A) semi-intensive free-stall, (B) non-intensive tie-stall, and (C) intensive free-stall. Additionally, protein levels of mature brain-derived neurotrophic factor (mBDNF) and its precursor form (proBDNF) and indoleamine 2,3-dioxygenase (IDO1) specific activity were evaluated in brain samples collected from 12 cattle culled between 73 and 138 months of age. Alterations in plasma lipid composition and in the kynurenine pathway of tryptophan metabolism were observed in the tie-stall-reared animals. The total plasma BDNF concentration was higher in tie-stall group compared to the two free-housing groups. Brain analysis of the tie-stall animals revealed a different mBDNF/proBDNF ratio, with a higher level of proBDNF (p < 0.001). Our data are similar to previous studies on animal models of depression, which reported that inhibition of the conversion of proBDNF in its mature form and/or elevated peripheral kynurenine pathway activation may underlie cerebral biochemical changes and induce depressive-like state behavior in animals. [ABSTRACT FROM AUTHOR]

Metals (trace elements and rare earth elements, REEs) were analysed by inductively coupled plasma-mass spectrometry in blood, the liver, the kidney and muscle of ex situ spotted dogfish (Scyliorhinus stellaris). The controlled environment in which these elasmobranchs were hosted allowed to assess a baseline level of metals in the different organs since exposure via water and food can be easily monitored. The highest arsenic, chromium, copper, and iron values were found in the liver, cobalt in the kidney, and cadmium and rubidium in muscle. The highest total trace elements content was found in the trend liver (75 mg kg−1) > blood (33 mg kg−1) > muscle (31 mg kg−1) > kidney (10 mg kg−1), while the ΣREEs was the liver (30 μg kg−1) > muscle (15 μg kg−1) > kidney (13 μg kg−1) > blood (4.1 μg kg−1). Between REEs, the most represented element was scandium. Significant differences in the concentration of metals among organs were observed for almost all elements. Nonessential elements were generally lower and essential elements higher in the examined specimens compared to wild elasmobranchs, suggesting a close relationship between a balanced diet and animal welfare. [ABSTRACT FROM AUTHOR]

Nickel (Ni) is an essential element in plants and animals, but elevated levels can exert toxicity in living beings, as recently highlighted by the European Food Safety Authority opinion. However, literature regarding the presence of nickel in the environment is scarce. In 2016, the EU Commission Recommendation n°1110 recommended monitoring the presence of Ni in feed in order to set maximum levels or to adopt other risk management measures to ensure a high level of animal health protection and consequently of human health. A total of 200 samples of feedingstuffs, drinking water, and milk were collected from dairy cow farms in Piedmont, and analyzed for Ni concentration by Z-ETA-AAS. Results showed the presence of nickel in feedingstuffs in a range from 0.20 to 16 mg/kg, while Ni concentrations in water and milk were close to or below the limit of quantitation. There was no carry-over from feed to milk in this food chain. Nickel concentrations were not of concern for animal health despite being in the upper range of those observed in vegetables from Europe. [ABSTRACT FROM AUTHOR]