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Artificial reproduction in eels is very challenging due to their peculiar life cycle. No information is yet available on the influence of photoperiod on the sexual development of wild silver eels in captivity. Previous studies have demonstrated the photoperiod to influence sexual maturation of eels showing that dark conditions lead to a better reproductive performance in terms of a greater gonadal maturation and a higher egg production and spawning record. This study aimed to investigate the physiological mechanisms leading to different outcomes in light or dark conditions on the gonadal steroidogenesis in wild female European silver eels during pituitary extract treatment. The variation of the body weight index and gonadosomatic index suggested a positive effect in dark conditions. Sexual steroids (androgens and estrogens) showed a significant difference in plasmatic concentration in the animals kept in the dark suggesting a better wellness reproductive situation in this particular housing condition.

The assessment of cortisol concentration in hair has been proposed as a minimally-invasive technique capable of furnishing information over medium/long period stress response. The aim of the present work was to assess the reliability of using bristles as a matrix for the assessment of mean cortisol level in swine. To this aim, bristles were collected by shaving the rump region of 30 naturally synchronized sows housed in a commercial breeding farm, over two successive reproductive cycles. Samples were collected at three key physiological phases (before delivery-BD; weaning time-WT; pregnancy diagnosis-PD) during two consecutive reproductive cycles (1 and 2), which naturally developed in different seasons of the year (PD1 occurred in April, BD1 in June, WT1 in July, PD2 in September and BD2 in November). Samples were processed as follows: hair was repeatedly washed in water and isopropanol to remove the external debris. The sample was then dried, pulverized and 60mg were weighed. Methanol was added to the sample, and the vial was incubated overnight for steroid extraction. Methanol was then transferred to another vial, evaporated and stored at -20°C pending cortisol assessment, which was carried out by a validated RIA. Differences in cortisol levels between the sampling points were studied with one-way ANOVA and the post-hoc Duncan multiple range test. Two-way ANOVA was applied to evaluate the effects of reproductive phase and season. PD1 and PD2 values were 20.10±1.95 and 16.29±2.15 pg/mg, respectively and were significantly higher (P

Boar welfare is a key factor in swine semen production and laboratory use. Hair analysis has been proposed as a minimally-invasive technique able of providing information on the stress response over the medium- to long-term period. Hormonal fluctuation in bristle could be a valid tool to study pig stress and metabolic responses. The aim of the present work was to determine cortisol (CORT) and testosterone (TEST) concentrations in hair, in relation to temperature and sperm viability. Two Italian Large White boars, of proven fertility, aged 6 and 9 years were used for the study; they were housed in 6m2 wide boxes, under artificial illumination and with controlled air temperature. Hair was collected monthly, semen was collected once every two weeks, environmental temperature was determined 6 times a day and mean temperature (Tmed), maximum temperature (Tmax) and minimum temperature (Tmin) were recorded every two weeks. CORT and TEST hair concentrations were measured, after one water and two isopropanol washings and methanol extraction from the matrix, by a validated RIA technique; sperm viability was determined by fluorescent probes (Propidium iodide to stain dead cells’ nucleus in red and Sybr green 14 to stain live cells’ nucleus in green). An ANOVA for repeated measures was used to analyze CORT, TEST and sperm viability changes during the different months; Pearson’s correlation test was used to evidence correlation between CORT, TEST, viability and temperature. There is no difference in CORT, TEST and sperm viability during the different months of the year; CORT is negatively correlated to Tmin (R=-0.33, p

The purpose of this study was the evaluation of total plasma thyroid hormones (TH) (T3 and T4) concentration in foals affected by Perinatal Asphyxia Syndrome (PAS) compared to healthy foals. Twenty-one healthy and 24 PAS foals £7 days-old were included in this study. Jugular blood samples were collected at birth/admission and every 24 h for 7 days (T0–T7). TH concentrations were analyzed by radioimmunoassay (RIA). Statistical analysis was carried out to evaluate: the time-dependent changes in TH concentrations in healthy and PAS foals, the comparison in TH concentration at admission between surviving and nonsurviving foals, and between healthy and PAS foals evaluated for age at admission. In both groups, T3 concentration significantly decreased at T5 compared to T1 (p< 0.05), and T4 plasma levels significantly decreased from T0 (p< 0.01). No differences were found in T3 and T4 concentrations at admission between surviving (n.20) and nonsurviving (n.4) foals. Statistical comparison between healthy and PAS foals divided in age groups showed a significantly lower T3 and T4 concentration at T0 in PAS foals (p< 0.01). In conclusion, the lower TH concentrations in PAS foals could be due to an ‘euthyroid sick syndrome’, that represents an adaptive response to reduce metabolic rate and to prevent organ failure, as reported in human neonates. TH concentration showed no prognostic value, maybe due to the small number of nonsurviving foals in this study.

Little is known about polar bears endocrine profile since existing data focused primarly on sun (Ursus malayanus) and Formosan bear (Ursus thibetanus formosanus). This research aims at evaluating sexual profile in two captive pubertal polar bears by the monitoring of progesterone, estradiol and testosterone in fecal samples. Faeces were collected from one male and one female and stored frozen until analysis. Hormone extraction was performed on 0.3 g homogenized faeces with a double ethanol extraction and analyzed with commercial RIA kits for progesterone (P4), estradiol (E2) and testosterone (T). Progesterone was also measured using commercial ELISA kits. RIA and ELISA gave comparable data with p

A new matrix, i.e. hair, has been recently utilized for the evaluation in some species of mean cortisol level as an indicator of chronic stress condition. In order to assess the validity of this approach for swine, we collected and analyzed bristles from 30 sows housed in a breeding farm, over two successive reproductive cycles. Our data gave clear indication of the reliability of this matrix, indicating, in both cycles, a higher activation of the adrenal response during late pregnancy, delivery and early lactation. Furthermore from our data it is possible to presume the existence of a seasonal variation of cortisol level, with the lowest values recorded during the hot season. It would be interesting to evaluate if this reduction in cortisol level during the hot season plays a role in seasonal infertility of swine.

This study evaluated the carry-over effects of ewe body reserves during early pregnancy on peri-partum adipose tissue metabolism. Forty-nine multiparous ewes were divided in three categories according to their body condition score (BCS) at day 30 of pregnancy (BCS 3, 2.5-2.75; BCS = 3; BCS 3, 3.25-3.5). Live-weight (LW) and BCS gains from 1st to 4th month of pregnancy were greater in ewes with BCS 3 and 3 than in3 animals. In contrast, in the last month of pregnancy, there was BCS decrease in all groups, although LW continued increasing. There were no differences in LW or BCS across ewe categories during this period. Peripheral leptin levels throughout the three last weeks of pregnancy were greater in ewes with BCS 3 than in the rest, but this difference did not persist after lambing. Plasma metabolites related to energy metabolism, milk yield and lamb growth were not affected by ewe BCS in early pregnancy. Long-chain saturated milk fatty acids (FA) (C16-C24) were greater in ewes with lowest BCS (3 and 3). Ewes with greater BCS showed greater monounsaturated and lowest polyunsaturated milk FA content. Ewe post-mating body reserves affect both pre-partum leptinaemia and post-partum milk polyunsaturated fatty acids content, but it had little effect on lamb performance.

Many hormones are involved in the regulation of male reproductive functions, controlling sexual behavior, and influencing sexual arousal, the onset of erection and ejaculation, and the post-ejaculatory detumescence. The aims of this study were to analyze the plasma concentrations of 15-ketodihydro-PGF(2α) (PGFM), LH, testosterone (T), oestrone sulphate (OS), and cortisol (C) in relation to sexual stimulation and to evaluate the possible correlations among circulating hormones and between hormones and semen characteristics in the donkey stallion. Thirteen sexually experienced Martina Franca jackass of proven fertility were enrolled and semen was collected through an artificial vagina. Plasma samples were collected at 12, 9, 6 and 3 min before oestrous jenny exposure, at the first erection in the mating arena in the presence of an oestrous jenny, during ejaculation, at dismounting, 3, 6, 9 and 12 min after ejaculation in box, and then every 10 min during the following 50 min. PGFM showed an increasing trend with significant differences between the pre-ejaculatory and post-ejaculatory period, suggesting a role of this hormone in the control of ejaculation. LH showed a significantly higher concentration at ejaculation compared to last samples, while T showed significantly higher levels at erection, ejaculation and dismounting, probably for its influence on these processes and on sexual behavior. Finally, OS did not show any difference in the period of observation, while C presented a significant increase only 22 minutes after erection. The only hormonal correlation found was a positive one between LH and T at erection and dismounting, while T and OS were positively correlated with total and progressive motility, respectively.

Sei scrofe convenzionali sono state inseminate con seme sperimentalmente infettato con PCV2 mentre 3 soggetti con seme addizionato del solo terreno di coltura privo del virus. Solo 3 dei 6 animali sperimentalmente infettati sono risultati gravidi ad un controllo ecografico al 29° giorno post-inseminazione, mentre tutti i controlli sono risultati gravidi. La viremia è stata dimostrata in 4 soggetti su 6 del gruppo degli infetti che, rispetto al gruppo di controllo, hanno anche presentato titoli anticorpali anti PCV2 più persistenti. Il soggetto del gruppo degli infetti a più basso titolo anticorpale (1:100) all’inizio della sperimentazione ha mostrato la viremia più prolungata ed il maggiore numero di feti PCV2 positivi (10 su 16). In una placenta si è rilevata necrosi coaugulativa focale del chorion positiva all’indagine immunoistochimica per PCV2. Lo studio complessivamente ha permesso di dimostrare che: 1) l’esposizione intrauterina in suini convenzionali può riprodurre l’infezione; 2) un basso titolo anticorpale aumenta la probabilità di infezione; 3) l’infezione da PCV2 contestualmente alla fecondazione, riduce la probabilità di gravidanza; 4) il substrato anatomoistopatologico della sofferenza fetale va individuato anche in lesioni placentali.

Diversi ormoni entrano in gioco nella regolazione della fisiologia riproduttiva nella cavalla.Tra questi, il progesterone (P4), il 17-β-estradiolo (E2) e il fattore di crescita insulino-simile I (IGF-I) giocano un ruolo fondamentale. Lo scopo di questo studio è stato quello di fornire un quadro completo delle variazioni ormonali durante il ciclo estrale della cavalla, tramite la valutazione dei livelli plasmatici di P4, E2 e IGF-I nel periodo compreso tra due ovulazioni successive. A questo scopo 10 cavalle sono state esaminate ecograficamente ogni 12 ore a partire dall’inizio dell’estro fino all’ovulazione

The aim of this study was to evaluate periovulatory plasma levels of progesterone and estrogens in the mare. Eighteen mares were ultrasonographically monitored for follicular growth and blood collected to analyse progesterone and estrogens plasma levels. Hormones were evaluated by RIA on plasma collected every 12 h from 24 h before and 24 h after ovulation, and at pregnancy diagnosis.

Per verificare l’esistenza di una correlazione tra attività steroidogenica e sensibilità del CL alle PGF2α, 170 cavalle, trattate con 75 μg di D-cloprostenolo sul rilievo ecografico di un CL attivo, sono state sottoposte a prelievi ematici prima della somministrazione delle PGF2αe 3 giorni dopo per la determinazione della progesteronemia. E’ stato riscontrato un errore del 22.4 % nel rilievo ecografico di CL attivo, mentre la luteolisi è stata registrata nel 64,4%.. In conclusione l’analisi dei risultati, pur non evidenziando una diretta correlazione tra attività steroidogenica e sensibilità alle PGF del CL nella cavalla, evidenzia come un calo del P4 superiore al 91.6% rispetto al valore pre trattamento 3 giorni dopo la somministrazione di 75 μg di D-cloprostenolo, possa essere considerato come indice di avvenuta luteolisi.

Lo scopo del lavoro è stato quello di valutare i livelli plasmatici di ACTH e cortisolo e il loro rapporto (A/C) in puledri sani (alla nascita, dopo 12 e 24 ore) e in puledri sottoposti a terapia intensiva (all'ammissione e dopo 24 ore). N.31 puledri (con meno di 5 giorni di vita) sono stati assistiti: n.7 sani (gruppo 1), n.12 setticemici sopravvissuti (gruppo 2), n. 7 setticemici deceduti e n.5 puledri affetti da Sindrome da Asfissia Perinatale (gruppo 4). Nel gruppo 2, i livelli di cortisolemia sono risultati significativamente più bassi dopo 24 ore di terapia intensiva. I livelli di ACTH e cortisolo plasmatici sono risultati significativamente differenti tra il gruppo 1 e i gruppi 2 e 3. I livelli di ACTH e il rapporto A/C erano anche differenti tra il gruppo 2 e 3. I livelli ormonali del gruppo 4 non hanno rilevato risultati significativi. La valutazione della funzionalità surrenale sembra essere molto utile nel monitoraggio del puledro neonato setticemico, con valore diagnostico e prognostico.

The aims of this study were to evaluate the effects of conjugated linoleic acids (CLA) on productive performance and at endocrine-metabolic level in the transition dairy cow. Seven weeks before the expected calving, two homogeneous and comparable groups of animals were formed (5 animals in each group) to allow the daily administration, in the treated group, of synthetic rumen protected CLA from 4 wk before predicted calving until 4 wk postpartum. Blood samples were collected weekly from -4 until +14 weeks after calving in order to evaluate the metabolic and endocrine profile and daily have been recorded individual milk yeld, body condition score, and body weight. CLA supplementation had no detectable effects on plasma insulin, GH, IGF-1, NEFA and glucose concentrations, however these preliminary results seem to indicate a significant decrease (P

La ghrelina, ormone proteico prodotto principalmente nello stomaco, è implicata nei processi di crescita e di regolazione metabolica e nell’omeostasi energetica. Questo ormone, viste le sue molteplici funzioni, potrebbe essere coinvolto nei processi endocrino-metabolici che mantengono la bovina da latte in una condizione di omeoresi tali da garantire un andamento fisiologico della lattazione. Lo scopo del presente lavoro è stato quello di determinare le variazioni della concentrazione plasmatica della ghrelina in bovine da latte durante la lattazione e l’asciutta. La ricerca è stata condotta su 146 bovine pluripare di razza Frisona Italiana, omogenee per numero di lattazioni e per produzione di latte. Gli animali sono stati allevati in stabulazione libera con area di riposo a cuccetta ed alimentati secondo la tecnica dell’unifeed con diete formulate in funzione del periodo produttivo. Nel corso della sperimentazione sono stati effettuati prelievi di sangue nelle diverse fasi di lattazione (giorni 50, 80, 110, 150 e 230) e nel periodo d'asciutta (giorni 290 e 350). Sui campioni ematici, con metodiche RIA ed enzimatico-colorimetriche, sono state dosate le concentrazioni plasmatiche di ghrelina, GH e NEFA. La concentrazione plasmatica della ghrelina, su valori molto bassi dopo 50 gg di lattazione (106,0 ± 3,37 pg/ml) è poi aumentata nelle fasi successive senza però mai presentare differenze significative. Le concentrazioni plasmatiche di GH e di NEFA, invece, si sono modificate significativamente in relazione alle fasi di lattazione e di asciutta con livelli massimi in corrispondenza del 50° giorno post-partum. Alla luce di questi risultati la ghrelina non sembrerebbe coinvolta nei processi endocrini che regolano la lattazione.

Ghrelin, a novel endogenous ligand for GH secretagogue receptor, has been recently isolated from the stomach. Its administration to rodents and humans stimulates GH secretion, increases food intake and reduces fat utilization. Recent studies in rodents suggest that ghrelin is involved in energy homeostasis and is influenced by nutritional status; however, scarce information is available about blood ghrelin levels in domestic animals. The aim of this study was to evaluate the effects of fasting and refeeding on plasma ghrelin levels in gilts. Eight prepubertal, ovariectomized gilts were fitted with an indwelling jugular catheter under general anesthesia. Two days later the gilts were bled every hour for a 4 h period during normal alimentation (time 0); after that, the gilts were fasted for 72h with free access to water. During this period, blood samples were collected at 6, 12, 24, 48 and 72 hours of fasting. After fasting, the animals were refeed and blood samples were collected each hour for an additional 4h period. After appropriate treatment with EDTA and aprotinin, acidified plasma samples were assayed for ghrelin concentrations by RIA using a polyclonal antibody specific for the N-terminal portion of human ghrelin, known to represent the active circulating form of the hormone. The antibody has been recognized to react also with porcine acylated portion of ghrelin. The assay was validated by verifying the parallelism of dilutions of plasma samples with the standard curve. Ghrelin plasma levels before fasting were 115.34+/-5.92 pg/ml. Throughout fasting they progressively increased to reach the highest concentrations at the end of fasting (163.9+/-10.42 pg/ml; P

VEGF is an important regulator of both angiogenesis and vascular permeability and it appears to be involved in the development of corpus luteum as well as in its regression in several species. VEGF production has been shown to be modulated by a variety of stimuli, among which nutrient shortage seems to play an important role. Recently we have demonstrated that short-term fasting in gilts increases VEGF concentrations in follicular fluid and VEGF mRNA levels in theca layer (Galeati et al., Reproduction, 126:647-652, 2003). This study was aimed at verifying whether fasting influences VEGF mRNA expression as well as steroidogenesis in pig CL. Eight prepubertal gilts were treated with 1250 IU eCG followed 60 h later by 750 IU hCG in order to induce follicle growth and ovulation. Five days after hCG treatment, the animals were divided into two groups: group A - normal alimentation with a commercial diet, group B - 72 h of fasting with water available at all times. Ovaries were collected 8 days after hCG treatment and the single CLs (10/sow) were cut in two halves. One half was weighed, homogenized in PBS (0.1 g/ml) and stored at -20°C until measurement of steroid content (progesterone, testosterone and estradiol-17beta); the second half was treated with Tri-Pure (50 mg/ml) and stored at -80°C until VEGF mRNA levels determination. Fasting significantly (P