Elisabetta Micera

Stress-related hormones in horses before and after stunning by captive bolt gun.

In this work the slaughter-linked plasma modifications of some stress-related hormones in horses subject to standardized butchering procedures were investigated in order to highlight the compromised animal welfare during pre-slaughter handling. During pre-slaughter, animals show strong hardship behavioural patterns, probably due to being under life-threatening conditions. Blood samples from 12 male horses, ageing from 3 to 5 years, were collected before slaughtering in lairage, and during exsanguination after stunning. Catecholamines, cortisol and beta-endorphin concentrations were assessed in plasma samples by EIA. Results show that plasma beta-endorphin concentration did not increase significantly after stunning, while cortisol (P<0.05) and catecholamines (P<0.001) increased significantly. The ratio between the plasma level of norepinephrine and epinephrine decreased significantly (P<0.001) during the time considered for observation underlining a greater involvement of adrenal medulla in the stress response. Moreover these results suggest that, under stress, the release of beta-endorphin could be different from that of ACTH.

Delta opioid receptor on equine sperm cells: subcellular localization and involvement in sperm motility analyzed by computer assisted sperm analyzer (CASA)

BackgroundOpioid receptors and endogenous opioid peptides act not only in the control of nociceptive pathways, indeed several reports demonstrate the effects of opiates on sperm cell motility and morphology suggesting the importance of these receptors in the modulation of reproduction in mammals. In this study we investigated the expression of delta opioid receptors on equine spermatozoa by western blot/indirect immunofluorescence and its relationship with sperm cell physiology.MethodsWe analyzed viability, motility, capacitation, acrosome reaction and mitochondrial activity in the presence of naltrindole and DPDPE by means of a computer assisted sperm analyzer and a fluorescent confocal microscope. The evaluation of viability, capacitation and acrosome reaction was carried out by the double CTC/Hoechst staining, whereas mitochondrial activity was assessed by means of MitoTracker Orange dye.ResultsWe showed that in equine sperm cells, delta opioid receptor is expressed as a doublet of 65 and 50 kDa molecular mass and is localized in the mid piece of tail; we also demonstrated that naltrindole, a delta opioid receptor antagonist, could be utilized in modulating several physiological parameters of the equine spermatozoon in a dose-dependent way. We also found that low concentrations of the antagonist increase sperm motility whereas high concentrations show the opposite effect. Moreover low concentrations hamper capacitation, acrosome reaction and viability even if the percentage of cells with active mitochondria seems to be increased; the opposite effect is exerted at high concentrations. We have also observed that the delta opioid receptor agonist DPDPE is scarcely involved in affecting the same parameters at the employed concentrations.ConclusionsThe results described in this paper add new important details in the comprehension of the mammalian sperm physiology and suggest new insights for improving reproduction and for optimizing equine breeding.

Reduction of the olfactory cognitive ability in horses during preslaughter: Stress-related hormones evaluation

As horses may perceive several odour signals of danger at slaughter, application of mentholated ointment to their nostrils may limit their perception of danger. To assess the effect of the application of a mentholated ointment to horse nostrils on the stress response during pre-slaughter handling, plasma levels were evaluated for cortisol, beta-endorphin, epinephrine and norepinephrine prior to and after stunning. Twenty draught-type horses were divided into control (n=10) and treated (n=10) groups and a mentholated ointment applied to the nostrils of the treated horses following blood sampling in lairage 45 min prior to slaughter. Treatment did not affect plasma concentrations of beta-endorphin or cortisol but significantly reduced the concentrations of epinephrine and norepinephrine observed in post-stun plasma. These results indicated that mentholated ointment applied to the nostrils of horses pre-slaughter reduced their adrenergic response to the slaughter environment, implying that the stress response may be reduced with this technology.

Evaluation of animal welfare and milk production of goat fed on diet containing hydroponically germinating seeds

Abstract Hydroponic fodder is a particularly nutritious feed, rich in protein and vitamins such as ß-carotene, trace elements and enzymes. It may also offer the advantage of a continuous availability. A pilot plant for hydroponically production of germinating seeds was built in an area of the same farm where the trial took place. Three homogeneous groups of 30 Jonica breed goats in lactation (4th-5th parity) were used to evaluate the effects of two different levels of partial dietary substitution with hydroponically germinating (h.g.) oat on plasma levels of cortisol and milk production. Germinated oat was used after 7 days of hydroponic growth. Control group (T) received only feed (fodder and oat integrated with complement feed). The other 2 groups were fed on diet containing different levels (1,5Kg - group A; 3Kg - group B) of hydroponically germinating oat. Goats showed a small interest in fresh feed during the trial period. The integration with hydroponically germinating oat in partial substitution of the traditional feed in the diet of goat did not significantly affect biochemical and haematological parameters.

Stress indicators in steers at slaughtering

Abstract This work aimed to assess the blood modifications of some slaughtering-linked stress hormones in cattle subject to butcher standardized procedures. The blood samples of 20 Limousine 12-13 months old steers have been collected before slaughtering, during lairage, and after stunning by captive bolt gun, during exsanguination. The plasma level of epinephrine, norepinephrine, cortisol and beta-endorphin have been assayed by EIA. The data indicate that catecholamines, cortisol and beta-endorphin did not significantly increase after stunning in these animals.

Improvement of sheep welfare and milk production fed on diet containing hydroponically germinating seeds.

Abstract Plasma cortisol and milk production responses of 45 lactating Comisana sheeps (4th5th parity), divided into three homogeneous groups of 15 subject each, were used to evaluate the effects of two different levels of partial substitution of a complete feed with hydroponically germinating seeds. Germinated oat was employed after 7 days of hydroponic growth. The three groups received the following diets: Control group (T) received only complete feed. The other 2 groups were fed on diet containing different levels of hydroponically germinating oat (1,5 kg – group A; 3 kg – group B). All the subjects have shown to accept the diets because the per capita ration was always completely consumed. In the second month, the A and B groups showed lower average values of cortisol (P<0.01) and a statistically significant increase in milk production as compared to T (P<0.05 and P<0.001). The obtained data induced to conclude that integration with hydroponically germinating oat in partial substitution of the complete feed does not modify biochemical and hematological parameters and seems to produce an improvement in animal welfare and production of milk.

A functional study on L-type calcium channels in granulosa cells of small follicles in laying and forced molt hens

To investigate Ca(2+) dynamics in earlier phases of follicular development we compared the resting [Ca(2+)](i) and tested the functional responses to agonist/antagonist of L-type voltage-operated calcium channels (VOCCs) in small follicles GCs from hens during oviposition (O-GCs) and forced molt (M-GCs), using the microspectrofluorimetric [Ca(2+)](i) imaging. O-GCs were obtained from prehierarchical follicles (F(6)-F(5)-F(4)<8mm). In basal and agonist/antagonist stimulated M-GCs we did not observe a change in the [Ca(2+)](i) under any of condition in all cells analyzed. Based on basal measurements we can distinguish three different patterns reflecting cells variability within O-GCs group: (a) 39% cells showed small oscillations and [Ca(2+)](i) was 108±11nM; (b) 36% cells displayed yet small oscillations and [Ca(2+)](i) was 167±14nM; (c) 25% were cells with repetitive irregular oscillations that peaked until 2 fold basal value and [Ca(2+)](i) very variable, was 248±41nM. In O-GCs L-type VOCCs stimuli displayed different effects on [Ca(2+)](i) for both treatment in three basal patterns. In our study we demonstrated: (1) at resting the [Ca(2+)](i) is low (111±5nM) in M-GCs and tend to increasing in prehierarchical O-GCs; (2) L-type Ca(2+) channels are functionally expressed in the major part of O-GCs whereas they are not activated nor inhibited in M-GCs and in a percentage of O-GCs; (3) there are three different cellular types in prehierarchical O-GCs that may be associated with increasing stages of follicular development, based on their Ca(2+) pathway. Therefore, the functional response of L-type Ca(2+) channels in cultured laying hen prehierarchical GCs may be correlated with the functional maturation phase of laying hens ovarian. We hypothesize that the L-type Ca(2+)-dependent signaling could have a critical role in the regulatory mechanisms hormone mediated in hen ovarian cycle.