Determination of Salivary Cortisol in Donkey Stallions

Events with Different Emotional Valence Affect the Eye's Lacrimal Caruncle Temperature Changes in Sheep

Infrared thermography (IRT) has been recently applied to measure lacrimal caruncle temperature non-invasively since this region is related to the sympathetic response, and it seems a promising technique that is able to infer negative emotions in sheep (e.g., fear). However, the scientific literature so far is limited in understanding whether a caruncle's temperature changes also in response to positive emotional states in sheep. Through classical conditioning, we aimed to assess how a positive or a negative event affects the physiological (lacrimal caruncle temperature measured with IRT and cortisol levels) and behavioral responses of sheep (ear position). Fourteen ewes from the same flock were randomly assigned to two treatment groups: positive (n = 7) and negative (n = 7). Each group was then trained through classical conditioning to associate a neutral auditory (ring bell) stimulus to an oncoming event: for the positive group, the presence of a food reward (maize grains), while for the negative one, the opening of an umbrella. After three weeks of training, before (at rest) and after (post-treatment), lacrimal caruncle temperature was non-invasively measured via IRT, and saliva samples were gently collected to measure cortisol levels. During treatment, sheep behavior was videorecorded and then analyzed using a focal animal sampling technique. At rest, the eye's lacrimal caruncle temperature was similar in both groups, while post-treatment, a significant increase was shown only in the negative group (t-test; p = 0.017). In the anticipation phase, sheep in the positive group kept their ears forward longer compared to those in the negative one (Mann-Whitney; p < 0.014), 8.3 ± 2.1 s and 5.2 ± 4.2 s, respectively. The behavioral response observed reflects a learnt association between a neutral stimulus and events with different emotional valence. Cortisol concentration slightly increased in both groups post-treatment. Our results confirm that IRT is a non-invasive technique that can be useful when applied to assess how positive and negative events may affect the physiological response in sheep.

The Correlation between Play Behavior, Serum Cortisol and Neutrophil-to-Lymphocyte Ratio in Welfare Assessment of Dairy Calves within the First Month of Life

Welfare assessment of dairy calves is commonly conducted through the observation of their behavior and the analysis of physiological parameters. Despite the large number of studies on this topic, there is a lack of research on the possible correlation between the physiological parameters and behavior at basal level in dairy calves. For this reason, the present study aimed to investigate the possible correlations between serum cortisol, neutrophil-to-lymphocyte ratio (N/L) and locomotor play behavior in 21 Friesian dairy calves within their first month of life. Every week, an arena test after blood collection was performed. A significant positive correlation between serum cortisol levels and N/L (rrm = 0.381; 95% CI = 0.083, 0.617; p = 0.012) and a negative correlation between time spent running and N/L (rrm = −0.351; 95% CI = −0.575, −0.077; p = 0.012) were found. On the contrary, no significant correlation between time spent running and cortisol levels was detected. Cortisol levels and N/L were higher in the newborn and had a constant decrease until reaching a stable value after the 24th day of life. These findings suggest a better predictivity of N/L, compared to serum cortisol, on locomotor play behavior.

Impact of Human-Animal Interactions on Psychological and Physiological Factors Associated With Veterinary School Students and Donkeys

There has been an increased interest in evaluating human-animal interactions and assessing the mutual health and wellbeing. In this study, first-year female and male veterinary school students not paired (n = 58) or paired (n = 25) with immature (≤9 mo) donkeys (n = 13) were engaged in three different types of interactions (1st, hands-off remote learning, 2nd, hands-on passive learning, and 3rd, hands-on active learning) for 30 min each during Week 2 (Time 1), Weeks 5-8 (Time 2), and Week 12 (Time 3) over three, 15-week periods. Student psychological data involved the Penn State Worry Questionnaire (PSWQ) scores collected from the interactive (student-donkey pairs) and non-interactive (no student-donkey pairs) groups and modified Comfort from Companion Animals Scale (CCAS) scores collected from the interactive group during Times 1, 2, and 3. Donkey physiological data involved collection of saliva within 10 min pre- and post-interaction during Times 1, 2, and 3 in association with the different types of interactions for immunoanalysis of cortisol. There were no significant effects of the various times and types of interactions on CCAS scores. While there were no significant effects of group and types of interactions on PSWQ scores, there was an effect (P = 0.01) of time. Overall mean PSWQ scores were significantly lower during Week 12 versus Week 2. Correspondingly, while there were no effects pre- vs. post-interaction within or among times on saliva cortisol concentrations in donkeys, there was an effect (P = 0.02) of the type of interaction. Mean concentrations were significantly lower with the hands-on passive and hands-on active learning versus the hands-off remote learning. In conclusion, while this study provides preliminary evidence surrounding student donkey interactions, future studies are required with more comprehensive designs to clarify these benefits and better understand the advantages and challenges surrounding student-donkey interactions.

Ultrasonography Evaluation of Umbilical Structures in Clinically Healthy Donkey Foals during the First Week of Life

The umbilicus is a potential access-point for pathogens in equine foal, causing umbilical infections and potentially life-threating illness. Early diagnosis based on ultrasonographic appearance and measurement is crucial to avoid severe complications and promptly implement appropriate therapy. This study ultrasonographically evaluates the umbilical remnants of donkey foals, in the first week of life. Fifteen healthy donkey foals were included in the study. The umbilical vein, arteries and urachus ultrasounds were performed at 24 h, 3 and 7 days of life, using a portable ultrasound machine and a 5-7.5 MHz multifrequency linear probe. The Kruskal-Wallis test and Dunn's multiple comparisons test were applied to verify differences in relation to time for all the umbilical remnants measured. Statistical significance was set at p < 0.05. No statistical differences were observed in relation to time regarding umbilical remnant measurements. A correlation was found between body weight and the left artery at T0. The regression of the umbilical remnant during the first week of life was slower compared with what was reported in equine foals but was comparable with the results on calves. Thus, the different regression timing needs be considered when evaluating donkey foals with umbilical remnant diseases within the first week of life.

Two Hours of Separation Prior to Milking: Is This Strategy Stressful for Jennies and Their Foals?

Simple Summary

The economic importance of donkeys has decreased in Brazil, which has led to their mass abandonment. Asinine milk production is a potential solution to the reintroduction of donkeys into the Brazilian social and economic scenario. The milk has nutraceutical properties that make it valuable for human consumption, and thus a donkey dairy industry is likely to help stop their abandonment. That said, in any such industry, the welfare of jennies maintained for milk production must be guaranteed. Few studies have been published measuring the impact of milking management on the welfare of jennies and foals, and the potential behavioural and physiological challenges it may cause. It is also unknown whether these animals adapt to the milking routine. The goal of this study was to assess the impact of separating Pêga jennies from their foals for 2 h on indicators of welfare. Animal welfare was analysed through behavioural and hormonal assessments, their potential adaptive responses and effects on milk yield. Few significant alterations were found in behaviour, salivary cortisol concentrations, or milk yield as a result of the 2-h separation, which could indicate that the welfare of the animals was not compromised; however, the adaptation of jennies and foals to separation stress remains to be fully verified. The 2-h separation period, based on the reported data, is possibly not a stressful experience for the assessed group of Pêga jennies and foals. The reported protocol, which included frequent positive interactions with the animals, may be useful to assure acceptable animal welfare levels for donkeys in small-scale dairy production settings.

Abstract

The goal of this study was to assess whether or not a separation period of 2 h is stressful for jennies and foals, as measured by changes in behaviour, salivary cortisol, and milk production. This study was reviewed and approved by the Committee for the Use and Care of Animals in Research (CEUA) of the School of Veterinary Medicine and Animal Science of the University of São Paulo. Fourteen multiparous Pêga jennies (245 kg average body weight) and their foals were assessed from day 45 to 135 of lactation. Dams and foals were separated for 2 h prior to milking. Behavioural assessments and saliva samples were collected before and after separation, every 15 days, resulting in 14 samples per individual animal. Behavioural states (affiliative and inactivity) and events (agonistic, abnormal, eliminative and vocalisations) of the jennies were observed during 6 min in both periods. Moreover, milk yield was measured. Few significant behavioural and salivary cortisol changes were observed, and milk yield was not affected by cortisol levels in response to the separation. The 2-h separation period, on the basis of the collected variables, did not appear to be stressful for the assessed group of Pêga jennies or foals; however, their ability to adapt to milking routine stress remains to be investigated.

Habituation to Transport Helps Reducing Stress-Related Behavior in Donkeys During Loading

Adopting proper animal management strategies, including training, might reduce to a substantial extent the adverse effects of transport-related stress in animals. The aim of this study was to evaluate the effect of habituation to transport on stress-related behaviors and physiological indicators during loading and unloading in donkeys. Fourteen donkeys were recruited and divided in two treatment groups: Habituation (H; M = 5, F = 2) and Control (C; M = 5, F = 2). H donkeys were gradually habituated to be transported, traveling together with their mothers and other adult donkeys well-accustomed to transport, while C donkeys had never been transported before. Loading and unloading phases were video recorded and behavior was analyzed. Saliva samples for cortisol concentration determination were collected at rest and after unloading. Latency time to load was significantly shorter for H donkeys than C donkeys (Mann-Whitney; p = 0.004). C donkeys also showed significantly more stress-related behaviors (Mann-Whitney; p = 0.026) and required a higher but not statistically significant number of human interventions to load. Cortisol concentration increased in both groups, but no differences were found between them (Mann-Whitney; p > 0.05). These results suggest that habituation to transport could mitigate stress during loading procedures in donkeys reducing loading time, frequency of stress-related behaviors and diminishing the need of human intervention.

Radiographic parameters of the digit in a cohort population of Amiata donkeys

Background:

The most common musculoskeletal conditions reported in donkeys are related to the foot. Radiographic examinations are clinically important in the diagnosis of foot abnormalities and are commonly used. However, few studies have been conducted to establish the normal radiographic appearance of a donkey’s foot.

Aim:

To determine the radiographic features of the front digit in healthy Amiata donkeys.

Methods:

Radiographic examinations were performed on 56 forefeet of 28 Amiata donkeys. Three radiographic views of each front foot were taken: lateromedial, dorsopalmar and dorso-65°proximal/palmarodistal oblique. Seventeen angular and linear radiographic parameters and the crena solearis were evaluated in all forefeet, and 18 morphometric parameters were evaluated in 16 out of 56 forefeet. Statistical analysis was carried out on all the measures assessed.

Results:

The radiographic appearance of the forefoot was ascertained, and data were reported as median ± standard error, minimum and maximum values. No statistical differences were obtained between the right and left forefeet.

Conclusion:

The normal baseline parameters of the forefeet of Amiata donkeys were recorded and described and compared with other donkey breeds and horses. The findings highlighted that the donkey breed affects the radiographic parameters of the digit.

May Salivary Chromogranin A Act as a Physiological Index of Stress in Transported Donkeys? A Pilot Study

Road transport is known to be a stressful animal husbandry procedure as it induces the activation of two main physiological stress-related pathways: the hypothalamic-pituitary-adrenal cortex axis and the sympathetic-adrenal medulla axis. This preliminary study aimed to investigate whether salivary chromogranin A (CgA) concentration, known as a biomarker of the sympathetic activity system during psychological stress, may represent a novel physiological index of transportation-induced stress in donkeys. Nineteen Romagnolo donkeys, raised in groups on paddocks, were subject to two transportations, following the farm's routine procedures, for a mean duration of 64 min each on two consecutive days. Salivary samples were gently collected 15 min before and 15 min after each transportation. Salivary CgA was measured by a commercially available enzyme-linked immunosorbent assay test. Results showed that CgA salivary levels significantly decreased after both transportations. The physiological mechanisms underlying this result may be related to catestatin activity, a bioactive product of the proteolytic cleavage of CgA, that acts as an inhibitor of catecholamine release. This hypothesis requires further investigation, particularly considering the limited number of subjects involved in this preliminary study. The identification of a reliable and non-invasive stress-marker would represent a useful tool for improving farm animals' welfare in transport conditions.

Relation between Apgar scoring and physical parameters in 44 newborn Amiata donkey foals at birth

The assessment of the behavior and physiological parameters of neonatal foals is essential in the detection of early signs of illness. Modified Apgar scoring systems from human medicine exist and have been validated in foals as a guide for assessing neonatal viability after birth. This study evaluated the viability of 44 Amiata donkey foals at birth, by assessing the Apgar score and comparing the relationship between viability and various physical parameters. A total of 44 Amiata donkey foals and 27 jennies were enrolled in this study. An expert operator examined each foal within 5 min of birth. A complete physical examination was performed, along with an existing four-parameter Apgar score. The presence of the suckling reflex was evaluated. The interval time needed to acquire sternal recumbency and quadrupedal position, as well as nurse from the mare, were recorded. In addition, heart rate (HR), respiratory rate (RR), and rectal body temperature (BT) were measured. Results were expressed as median ± standard error, minimum and maximum values. The effects of the Apgar score on time to reach sternal position and quadrupedal standing, time to nurse from the mare, RR, HR, and BT were estimated along with the differences related to Apgar scoring and gender. Differences between female and male donkey foals regarding the time to acquire sternal position and quadrupedal standing, time to nurse from the mare, RR, HR, and BT were also assessed. Differences between female and male donkey foals regarding the Apgar score was evaluated using a chi-Square test. Finally, the reference values for Amiata donkeys were also calculated. Twenty/44 (45.4%) foals were colts and 24/44 (54.5%) were fillies born from 27 jennies. None of the foals showed an Apgar score lower than 6. Twenty-nine out of 44 foals showed an Apgar score of 8/8, 10/44 a score of 7/8, while 5 foals (11.3%) showed a score of 6/8. No differences between fillies and colts in relation to the Apgar score were obtained.

Evaluation of Two Handheld Point-of-Care Blood Gas Analyzers in Healthy Donkeys

There has been increasing interest in blood gas analysis in donkeys. "Point-of-care (POC) testing" is a diagnostic testing performed on or immediately next to the patient. This study assesses the agreement between two POC blood gas analyzers in donkeys. Arterial and venous blood samples were collected from 17 donkeys and analyzed using a fully automated blood gas analyzer (ABL 700 Series Radiometer, Denmark) (RAD) and two POC blood gas analyzers (i-STAT System; VetStat, Idexx). The parameters revealed by all three devices were submitted to a canonical discriminant analysis, to evaluate which parameters differentiated the POC analyzers from the RAD. On the basis of the discriminant analysis, we evaluated the best POC for each parameter registered, in comparison with RAD. The results also changed depending on the type of blood (venous or arterial blood). The agreement between i-STAT and RAD was good for venous samples, but was poor for arterial samples. A poor agreement was found between VetStat and RAD for both venous and arterial samples. The increment of the number of subjects might lead to a better understanding of the potential role of the POCs in clinical setting. Finally, increasing the study population is recommended to set reference values.