Timed environmental exposure indicates sample stability for reliable noninvasive measurement of fecal cortisol metabolite concentrations in sheep

Comparing the agreement of a commercial cortisol kit with a biologically validated assay in evaluating faecal cortisol metabolite levels in koala joeys

Orphaned koala joeys constitute a substantial number of wildlife rescues. Mortality is highly prevalent in rehabilitating joeys, with little knowledge about the causes of mortality. The hypothalamic-pituitary-adrenal axis plays a vital role in mediating stress by producing glucocorticoids (e.g. cortisol), however, no studies have quantified glucocorticoids in koala joeys. Traditional cortisol enzyme immuno-assay (e.g. R4866) are limited in supply and are process intensive, whereas, modern enzyme immuno-assay (EIA) kits (e.g. Arbor Assay cortisol kit) are available world-wide and provide rapid results. Biological validation is unsuitable to be performed in recuperating joeys due to ethical considerations, hence, we compared the results from biologically validated R4866 assay with the commercially available Arbor Assay cortisol kit. Thirty-four faecal samples were collected, processed and analysed for faecal cortisol metabolites (FCM) using both, R4866 assay and Arbor Assay kit. The joeys presented a suite of clinical conditions which provided the natural variation in stress response for comparing the assay sensitivity and range. The results indicated that there were no significant differences between the FCM values measured by both the assays. Furthermore, the Bland-Altman plot indicated a very strong agreement between the FCM concentrations measured by the two assays. This study is only a step towards recommending the routine use of commercial kit in clinical settings with basic resources, for rapid quantification of stress in koala patients. It is crucial for future studies to perform laboratory validation procedures to confirm the efficacy of the commercial kit before practical use for FCM monitoring in koalas.

Analytical Methodology for a Metabolome Atlas of Goat's Plasma, Milk and Feces Using 1H-NMR and UHPLC-HRMS

Metabolomics has been increasingly used in animal and food sciences. Animal health is one of the most important factor that can also alter animal integrity and welfare. Some studies have already investigated the link between health and metabolic profile of dairy animals. These studies in metabolomics often consider a single type of sample using a single analytical platform (nuclear magnetic resonance or mass spectrometry). Only few studies with multi-platform approaches are also used with a single or a multi type of sample, but they mainly consider dairy cows’ metabolome although dairy goats present similar diseases, that it could be interesting to detect early to preserve animal health and milk production. This study aims to create a metabolic atlas of goat plasma, milk and feces, based on healthy animals. Our study describes a standard operating procedure for three goat matrices: blood plasma, milk, and feces using multiple platforms (NMR (¹H), UHPLC (RP)-MS and UHPLC (HILIC)-MS) that follows a unique sample preparation procedure for each sample type to be analyzed on multi-platforms basis. Our method was evaluated for its robustness and allowed a better characterization of goat metabolic profile in healthy conditions.

Effect of Different Finishing Strategies and Steer Temperament on Animal Welfare and Instrumental Meat Tenderness

Simple Summary

Animal welfare is one of the most important quality attributes for meat consumers and a potential tool for differentiation in farms where husbandry is based on extensive rearing systems and high animal welfare standards. However, there is not enough contextualized scientific information in relation to these systems and some others that are emerging, with a higher level of intensification. In this experiment, we compared animal welfare between different fattening systems, through the combination of several indicators regarding physiology, behavior, health, productivity, and meat tenderness. Animal temperament, as well as its impact on welfare and meat quality, was also considered. From our results, we concluded that finishing strategies based on pastures that ensure an adequate level of nutrition and health would be more appropriate for fattening animals, from both the animal welfare and the meat quality perspectives. Intensification up to certain levels (pasture plus supplement), without deprivation of certain behaviors and with constant monitoring of health, should provide productive benefits without compromising animal welfare. In confined systems with 9 m² per animal, the challenge is greater in relation to animal welfare because of restrictions of important behaviors and greater risks of dietary diseases. It is considered that, if some conditions of the confined system are improved, such as the space available per animal and the strict prevention and constant monitoring of diet disorders, it could be a valid alternative for fattening cattle. Temperament could be improved through good handling, with positive impacts on welfare, productivity, and meat tenderness.

Abstract

The aim of this experiment was to evaluate the effect of different fattening systems from pasture to concentrate and temperament on animal welfare (AW) and meat quality (MQ). Eighty-four Hereford steers were randomly assigned to the following groups: T1, pasture (4% of animal live weight: LW); T2, pasture (3% LW) plus concentrate (0.6% LW); T3, pasture (3% LW) plus concentrate (1.2% LW); T4, an ad libitum concentrate treatment. Temperament was assessed by three individual tests: crush score, flight time, and exit speed, building a multicriterial temperament index (TIndex). The flight zone was also registered for each treatment. AW was assessed through the integration of indicators of productivity, physiology, and behavior, as well as by monitoring the health status within each treatment. Shear force was registered for MQ. Differences in average daily gain were due to the different energetic composition of the diets (T4 > T3 > T2 > T1) and were not attributable to animal welfare problems. Animals from T4 had the higher average daily gain (ADG) but welfare was negatively affected, being evident through physiological indicators, the restriction or deprivation of relevant behaviors, diet-related diseases, and mortality. T1, T2, and T3 did not appear to compromise animal welfare. However, strict preventive measures and monitoring should be taken during the habituation process and when using any new diet that includes concentrate, because of possible dietary diseases. Shear force values were lower in T1. None of the animals in our experiment were excitable or aggressive, but there was a positive response to handling in all treatments. In addition, regardless of diet, calmer animals had higher average daily gain and lower shear force values; thus, temperament appears to have a significant influence on productivity and meat quality.