A New Extraction Method for the Determination of Oxytocin in Milk by Enzyme Immune Assay or High-Performance Liquid Chromatography: Validation by Liquid Chromatography–Mass Spectrometry

Chitosan-carbon nanofiber based disposable bioelectrode for electrochemical detection of oxytocin

Bioelectrodes with low carbon footprint can provide an innovative solution to the surmounting levels of e-waste. Biodegradable polymers offer green and sustainable alternatives to synthetic materials. Here, a chitosan-carbon nanofiber (CNF) based membrane has been developed and functionalized for electrochemical sensing application. The surface characterization of the membrane revealed crystalline structure with uniform particle distribution, and surface area of 25.52 m²/g and pore volume of 0.0233 cm³/g. The membrane was functionalized to develop a bioelectrode for the detection of exogenous oxytocin in milk. Electrochemical impedance spectroscopy was employed to determine oxytocin in a linear concentration range of 10 to 10⁵ ng/mL. The developed bioelectrode showed an LOD of 24.98 ± 11.37 pg/mL and sensitivity of 2.77 × 10^-10 Ω / log ng mL^-1/mm² for oxytocin in milk samples with 90.85-113.34 percent recovery. The chitosan-CNF membrane is ecologically safe and opens new avenues for environment-friendly disposable materials for sensing applications.

A Procedure for Oxytocin Measurement in Hair of Pig: Analytical Validation and a Pilot Application

Simple Summary

Oxytocin is gaining importance in human and animal studies because of its role in welfare stress response, but there is no evidence of oxytocin measurement in hair, which would allow an evaluation of this analyte over a long period of time. For this reason, in this study, a new immunoassay to measure oxytocin in the hair of pigs was developed and validated. In addition, the possible changes in concentrations of oxytocin in hair during the reproductive cycle of pigs were evaluated. The assay was precise and accurate and when applied to the hair extracts of pigs, higher oxytocin values were obtained at days 23 and 59 after farrowing in the winter–spring period. When oxytocin concentrations were compared to cortisone and cortisol, it showed moderate and low correlations, respectively. Based on the results of this report, oxytocin can be measured in the hair of pigs, and changes in concentrations can be detected during a pig’s reproductive cycle.

Abstract

There is growing interest in oxytocin as a biomarker of stress and welfare. The objective of this study was to develop and validate a procedure based on a highly sensitive immunoassay to measure oxytocin in the hair of pigs. In addition, a pilot study to apply this procedure to evaluate possible changes in concentrations of oxytocin in hair during the reproductive cycle of pigs at different periods of the year was conducted. This procedure used methanol for sample extraction, since it offered better recoveries than acetonitrile, and the immunoassay developed was precise and accurate for the quantification of the oxytocin in the hair. When this procedure was applied to hair collected at different times of the reproductive cycle and season, higher values were found at days 23 and 59 after farrowing in the winter–spring period. In addition, higher oxytocin values in the spring–summer period were found in hair collected 5 days before farrowing compared to winter–spring. Oxytocin in hair showed moderate and low correlations with cortisone and cortisol in hair, respectively. This study represents the first report in which oxytocin was measured in hair and could open new lines for future research about the measurement of oxytocin in pigs and other biological species as a biomarker of stress.

Dairy cattle welfare as a result of human-animal relationship – a review

Despite the various concepts of human-animal relationship, the welfarist approach to this problem is one of the most often considered in theory and used in practice. When dealing with issues related to dairy cattle welfare (DCW), it is necessary to take into account both the reality characteristic for animals used to obtain milk (e.g. the problem of automatic milking of cows) and for slaughter cattle (e.g. slaughter of culled animals). It is not surprising, therefore, that issues related to DCW are the focus of the attention of the public, researchers, breeders as well as the dairy and meat industries. The aim of this article was to possibly most comprehensively cover the above-mentioned issues, although due to its huge scope it was obviously necessary to limit the article to what I think are currently most important issues. That is why in the review I (1) characterized the issues related to the division of human responsibility for DCW; (2) discussed the importance of technology to human-animal relationship; (3) elaborated the matter of stress, emotionality of animals and their cognitive abilities in the aspect of “negative” and “positive” DCW; (4) considered the possibilities of non-invasive assessment of animal welfare in the future and (5) discussed topics related to improving the conditions of the slaughter of animals. In summary, it was proposed paying more attention than has been paid until now, to the assessment of positive DCW in scientific research and breeding practice. I also drew attention to the necessity of reliable information flow on the line of the breeder/milk producer - industry - consumer, as negligence in this area is one of the reasons for public disinformation regarding the level of animal welfare.