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Octopus vulgaris is a commercially valuable species. It is overexploited in the natural environment and is considered to be an innovative species for aquaculture. However, large-scale farming is generally designed only based on economic requirements, disregarding any form of enrichment that induces the natural behavior of aquatic species. Although many studies have shown the influence of environmental enrichment on terrestrial vertebrates, fish, and cephalopod mollusks, information on the effect of environmental enrichment on the body patterns of O. vulgaris is limited. Therefore, in this study, we assessed how different environmental conditions (Basic vs. Enriched) affect sub-adults of O. vulgaris kept in recirculation systems, through qualitative–quantitative studies of the main body patterns and their potential application in the commercial production of this species. The results indicated that octopuses kept in the enriched environment showed several body patterns and gained a significantly higher weight than those kept in the basic environment. The body patterns displayed by the individuals kept in the basic environment were similar to those exhibited under situations of hostility and inter/intra-specific conflict. Hence, the environment of octopuses needs to be enriched, especially for the large-scale production of this species.

One of the major problems in artificial eel reproduction is identification of broodstock with high performance reproductive characteristics. The aim of this study was to study population characteristics and the reproductive potential of eels (Anguilla anguilla) located in Valle Campo valley (Comacchio, Italy). A total of 200 eels/period (spring–summer and autumn–winter) were measured to obtain an external indicator of their maturation state. Morphometric parameters were used to calculate condition factor (K), eye index (EI) and pectoral fin length index (PFLI). Silver index analyses showed the lack of silver males and of fully mature females. Most represented females were yellow females at stage II. Silver females represented 27.9% of the population. Seasonal analysis shows how temperature reduction favoured the presence of silver females versus yellow females. Statistical analysis of EI, cranial (CI), PFLI and gonadosomatic (GSI) indexes showed that significant differences were found for EI, CI, PFLI and GSI between yellow and silver eels. No significant difference was found between stage III and IV silver eels, while a significant difference for EI was found between stage I and II yellow eels and for IC at stage II with respect to all other stages. The present study defined how Valle Campo could present environmental and trophic conditions which could favour precocious development of a population of silver females with a noticeable reproductive potential, to be used in open sea release or in artificial reproduction programmes. On the contrary, the valley seems to present unfavourable conditions for both development and sexual maturation of male eels.

Photoperiodic treatments have been of practical interest in controlling seasonal reproduction in sheep, goats and horses. Melatonin is the principal mediator of the environmental photoperiodic message. To investigate the intra- and inter-subject variability of melatonin 24 h rhythm, ten female Italian Saddle horses (8–10yrs old, mean body weight 525±30 kg), ten female Sarda breed sheep (2–3yrs old, mean body weight 40.5±2.8 kg) and ten female Sarda breed goats (3–4yrs old, mean body weight 38.9±4.1 kg), housed individually in a 4×4 m soundproof box equipped with 50×100 cm opening windows, were subjected to a natural photoperiod of the vernal equinox (sunrise 06:00h; sunset 18:00h). Blood samples were collected from each animal, every 3 h over a 48h period starting at 00:00h of day 1 and ending at 00:00h of day 3. Plasma melatonin concentrations were determined by direct radioimmunoassay (MelatoninDirect RIA, Labor Diagnostika Nord GmbH, Nordhorn, Germany). The application of single cosinor method substantiated a circadian rhythm of melatonin with a nocturnal peak in all studied species. The application of two-way ANOVA on the rhythmic parameters indicated statistically significant differences between the three species in all of the cosinor analysis-derived parameters of MESOR, amplitude, acrophase and robustness of rhythm. Analyses of intra- and inter-subject variability indicate that organization of the melatonin 24h rhythm is characterized by great accuracy of control within and between the individuals of a breed. In conclusion, features of the 24h rhythm of melatonin among species; however, the 24h rhythmicity of melatonin each species showed high stability within the various subjects and within the same subject. These findings must be taken into consideration when applying photoperiod and melatonin treatments for breeding purposes.

In aquaculture, the many chemicals used as therapeutics, prophylactics and growth promoters, can accumulate in fish and spread in the environment through effluent water. Nowadays, the focus of zootechnical productions has shifted towards the search for possible natural alternatives, considered safer for animals and consumers, with lower environmental impact. Herbal products are made of natural compounds, but “natural” is not necessarily synonymous of harmless, thus toxicity needs to be tested for each composition at different doses. Indeed, since herbal products' action is often dose-dependent, negative effects may be prevented by studying the posology according to the species and life stage. In this study, the effects of two different doses (0.05 and 0.1 mL/L) of a natural-based complementary feed, Gill Fish®, were assessed on the early stages of life of farmed rainbow trout (Oncorhynchus mykiss). The product was added daily to tanks containing rainbow trout eggs during the pre-hatching period, from 30 to 36 days post fertilization. Embryos mortality (evaluated three times during the six days of treatment; t0-t2) and zootechnical indices such as biomass, weight, length and number of alevins (all evaluated 3 and 4 weeks after the end of treatment; t3-t4), were analysed to assess both direct and indirect toxicity. Furthermore, whole body cortisol (from embryos and alevins; t0-t4) was measured to highlight potential stressful effects of the treatment. For each parameter, time was a statistically significative factor, while no differences were noticed between the three groups within the same time point. These results demonstrate that Gill Fish® had no harmful nor stressful effects, both immediately and short term; this herb-based product could therefore be a good candidate for future studies with different doses and/or longer administration, to evaluate its possible beneficial effects as an alternative to chemicals in aquaculture.

The red deer (Cervus elaphus L., 1758) is one of the largest deer species in the world. Females are seasonal polyestrous, with negative photoperiod: the increase of the night peak of melatonin determines the secretion of GnRH and, therefore, LH and FSH. To date there is little information regarding the hormonal control during pregnancy for this species; this could be due to the difficulty of sampling wild subjects, while farmed animals’ hormonal concentrations may not reflect the physiology of the animal in a natural state. In this study we evaluated the concentration of cortisol and progesterone, extracted from blood and hair, on 10 wild and pregnant red deer females. Belonging to the population of the Bolognese Apennines (Italy), the hinds were sampled in the January−March 2018 period, according to the regional selective hunting plan. Plasma progesterone (P4) ranged from a minimum of 1.9 to a maximum of 7.48 ng/mL; while hair P4 concentrations varied from 41.68 to 153.57 pg/mg. The plasma and hair cortisol ranges are respectively 0.4−2.97 ng/mL and 0.03−0.55 pg/mg; the only significant correlation was found between hair concentration of P4 and the date of death. The results of this preliminary study represent a small step towards a better knowledge of this species’ physiology during pregnancy.

The European eel has recently been included on the Red List of the International Union for Conservation of Nature (IUCN) as a critically endangered species. The rearing of Anguilla larvae is seen as a key bottleneck to the mass production of glass eels since very little ecological information is available regarding their natural nutrition. Studies of digestive physiology and ontogenetic development in eel larvae could provide useful information for solving some of the puzzles regarding larval fish culture. The aim of this study was to characterize the ontogeny of pancreatic enzymes (trypsin, lipase and amylase) and a peptide hormone regulator of pancreatic secretion (cholecystokinin) in terms of gene expression in European eel larvae from day 0 (P0) of hatching to 5, 10, 15 and 20 days post hatching during fasting. The results in the present study showed that all the genes selected were present, with different levels of expression and increasing trends, during larval development. At P0, the increase in the gene expression of lipase and amylase was higher than that of trypsin and cholecystokinin, confirming that enzymatic activity began before mouth opening and that larvae, provided with a complete enzymatic set, might have the capacity of digesting and absorbing various nutrients.

Simple Summary The red deer, also known as the royal deer or European deer, is an artiodactyl mammal belonging to the Cervidae family, widely diffused in almost all of continental Europe. At the beginning of autumn in the Northern Hemisphere, the mating season begins. The males of red deer, called stags, are synchronized with the females, called hinds; indeed, at the beginning of the mating season, they show a marked increase in testosterone to match the hinds’ estrus cycle. Gestation lasts about 230 days, so that calves are born in mid to late spring, the most favorable period for their survival. Scientific data on the reproduction physiology of this peculiar species in wild conditions are lacking, including hormonal variations during pregnancy. The present study describes mean levels of two critical hormones, cortisol and progesterone, in both blood and hair of wild pregnant red deer hinds. Correlation analysis confirmed how animals hunted in later phases of pregnancy have higher hair progesterone. Abstract The red deer (Cervus elaphus L., 1758) is one of the largest deer species in the world. Females are seasonal polyestrous, with negative photoperiod: the increase of the night peak of melatonin determines the secretion of GnRH and, therefore, LH and FSH. To date there is little information regarding the hormonal control during pregnancy for this species; this could be due to the difficulty of sampling wild subjects, while farmed animals’ hormonal concentrations may not reflect the physiology of the animal in a natural state. In this study we evaluated the concentration of cortisol and progesterone, extracted from blood and hair, on 10 wild and pregnant red deer females. Belonging to the population of the Bolognese Apennines (Italy), the hinds were sampled in the January–March 2018 period, according to the regional selective hunting plan. Plasma progesterone (P4) ranged from a minimum of 1.9 to a maximum of 7.48 ng/mL; while hair P4 concentrations varied from 41.68 to 153.57 pg/mg. The plasma and hair cortisol ranges are respectively 0.4–2.97 ng/mL and 0.03–0.55 pg/mg; the only significant correlation was found between hair concentration of P4 and the date of death. The results of this preliminary study represent a small step towards a better knowledge of this species’ physiology during pregnancy.

Contents The study of lipids and fatty acids (FAs) has been used in the assessment of egg quality because their composition can influence the fertilization rate, hatching, survival and growth of marine fish larvae. For these reasons, the lipid content (TL) and fatty acid composition of common sole (Solea solea) eggs were measured and correlated to egg and larval viability parameters throughout an entire reproductive season. Seventeen batches of fertile eggs obtained from natural spawning of captive breeders were characterized for the TL, FA profile, hatching rate (HR) and survival rate of larvae (SR) at 0–6 days post-hatching (dph). The egg FA composition reflected the composition of the feed supplied to the broodstock during summer and autumn (before and during vitellogenesis) rather than that supplied during the spawning season. In general, the egg FA profile showed minimal differences among the early-, mid- and late-spawning periods (possibly due to the change of the diet and/or water temperature) indicating that it is possible to obtain a similar egg quality in terms of egg FA profile over 2 months of spawning. Saturated FAs and monounsaturated FAs (MUFA) were positively correlated with HR, while TL, 22 : 6n-3 (DHA), 20 : 4n-6 (ARA), polyunsaturated FAs of the (n-3) series (n-3 PUFA) and polyunsaturated FAs of the (n-6) series were negatively correlated (p ≤ 0.05). MUFA, 20 : 5n-3 (EPA), n-6/n-3 were positively correlated with SR, while DHA, n-3 PUFA, DHA/EPA were negatively correlated (p ≤ 0.05). In conclusion, the feed supplied before and during vitellogenesis has a major role in determining the egg FA profile in common sole. The relationships found between TL and FAs with egg and larval viability parameters differ from many other farmed marine fish species, which may suggest the need for a specific broodstock feed for this species.

To improve the knowledge in chronophysiology we investigated the causal link between the most important physiological variable studied until now; ten Sarda ewes and ten Sarda goats, pluriparus not pregnant and no lactating, were used. Animals were housed under natural environmental conditions in a common stall, alfalfa hay and water were available ad libitum. Each animal was equipped with an Actiwatch-Mini® for recording total activity. Blood samples were collected every 4 h over a 48 h period for the assessment of melatonin concentration. Rectal temperature was recorded with a digital thermometer immediately before the blood sampling at each data point. Single cosinor method showed a daily rhythm of studied variables. Higher MESOR and amplitude values of melatonin and rectal temperature were observed in sheep than in goats. The diurnal acrophase of locomotor activity was statistically different from the nocturnal acrophase of melatonin and rectal temperature, with no differences between the two species. Robustness was statistically lower in total locomotor activity in comparison with the others two variables, with a differences due to species in melatonin daily rhythm. In conclusion, in small ruminants, melatonin and rectal temperature daily rhythms are strictly correlated, and are not associated with the locomotor activity rhythm.

Sperm density and performance of wild and farmed male European eels were evaluated to investigate the effect of maintenance in captivity on ejaculate quality. Hormonal stimulation (with human chorionic gonadotropin) lasted for 17 weeks. Different origins of the male European eels partially influenced the quality of the ejaculates. Indeed, wild animals (i.e., collected at a natural site) had greater sperm longevity during the hormonal stimulation, whereas there was no significant effect of the origin on sperm density, spermatocrit, the percentage of motile sperm, and plasma testosterone concentrations. The different origins of the males also affected fatty acid sperm content, with greater unsaturated fatty acid and omega-6 concentrations in wild eels and lesser concentrations of saturated fatty acids and omega-3 fatty acids in farmed eels. Regarding sperm quality of European eels, this is the first study that takes into account the effect of different origins of stimulated males (wild-caught compared with farmed) on sperm quality, and these findings may help to improve the production of high-quality gametes in this endangered species.

The reproductive performances of silver European eel in term of gonad development and egg production, employing slow-release implants with the androgen 17-MT (1Â mg) in combination with traditional weekly injection of carp pituitary extract (CPE) was evaluated. Wild female European eels (Anguilla anguilla) underwent a standard induction protocol with CPE and were randomly divided into three groups (N-group, no implant; Y-group, with implant; and control, C-group, no treatment). The results showed that 17-MT-treated females (Y-group) reproduced spontaneously about 6 weeks earlier than the N-group females with a saving of almost 40% in CPE and time of induction. Concerning artificial induction of maturation in female silver eels, our study demonstrated that they positively respond to androgen exposure also in terms of eggs productivity. Indeed, Y-group was more productive than N-group: in Y-group, 11 eels ensured an eggs production that exceeded 50% of initial body weight (BW), whereas in N-group only three eels have exceeded this value. The results suggest that 17-MT should be considered in future protocols for the improvement of the artificial reproduction of female silver European eels.

The aim of the study was to investigate the influence of early lactation on leptin and growth hormone (GH) during bathyphase. Forty lactating Sarda ewes were divided into two equal groups on the basis of their milk production levels: HIGH (>1100 g/day) and LOW (

Inclusion of sustained-release androgen implants into fertility treatment regimes of female freshwater eels has been proposed to benefit artificial maturation outcomes. This study sought to test whether co-administration of the androgen 17-methyltestosterone (17-MT) in combination with ‘traditional’ hypophysation of female European silver eels would affect egg quality and subsequent larval survival. Implants, containing 1 mg 17-methyltestosterone (17α-methyl-4-androsten-17β-ol-3-one in a matrix of cholesterol:cellulose = 95:5), were administered twice, at 1 and 5 weeks after onset of experimentation (MTA- and MTB-groups); control eels (Ctrl) were given a blank implant. Female eels received weekly injections with carp pituitary homogenates (CPH) from either Week 1 (MTA- and Ctrl groups) or Week 5 onwards (MTB-group). First 4 injections were made with 10 mg CPH/kg body weight (BW) in sterile physiological saline (0.9% NaCl); the subsequent 12 injections with 30 mg/kg CPH and thereafter, 40 mg/kg CPH was injected until fish were considered ready for induction of final maturation. Bi-weekly blood samples were collected (Day 0 onwards) and analyzed for levels of testosterone (T) and estradiol-17β (E2) by radioimmunoassay. After reaching maturity, fertilized eggs were obtained upon spontaneous spawning of co-housed breeders and egg performance (fertilization, hatching, survival rates) was recorded. No differences were observed between eels from the MTA- and MTB-groups; however, egg performance was notably better in eels treated with 17-MT + CPH compared to eels receiving CPH only, with hatching rates reaching mean values as high as around 70% for both 17-MT and CPH co-treated groups, but only averaging 21.0 ± 8.4% for eggs from the Ctrl-group. Furthermore, 17-MT treated eels displayed a more distinct pre-spawning peak for levels of plasma T and E2 and for body weight, the latter being indicative of increased batch fecundity. We conclude that androgen co-treatment holds promise for future development of eel captive breeding technologies. Statement of relevance Artificial propagation of the European eel is increasingly urgent to release the strain on natural populations. This study presents a novel approach to artificial maturation of female eels: centered around the incorporation of androgens during fertility treatment. Accordingly, increased performance was observed in terms of fertilization, hatching and survival rates, which contributes to completing the life cycle of this fish in captivity. © 2017 Elsevier B.V.

This study aimed to set up a method for the long-term management of Adriatic sturgeon, through the analysis of sex steroids and the genetic profiling of individuals in order to maximize the already reduced genetic variability of this species. Ten A. naccarii adults (nine of captive origin, one captured in the Ticino river and then moved into captivity) and eight subadults located in a semi-natural land-locked pond in Abbiategrasso (Milan, Italy) were analysed. Plasma testosterone differed significantly in the eight analysed subadults allowing their differentiation into two groups: the first group with an average testosterone concentration of 5.42 ± 1.31 ng/ml (probably female) and the second group with an average of 423.14 ± 75.97 ng/ml (probably male), as subsequently confirmed by artificial stripping. The plasma testosterone level was also significantly different between adult males and females (371.37 ± 43.58 vs. 95.34 ± 51.10 ng/ml), while the E2 levels showed no significant differences. Animals were genotyped on the basis of 10 microsatellite loci and their parental relationships were defined: four adults, two females and two males, generated the eight subadults. On the basis of pedigree analyses and genetic distances, 15 unrelated couples were identified for the future breeding seasons. Finally, the adult female captured in the Ticino River showed an interesting genetic profile, widely different from all of the other 17 specimens analysed, and represents a valuable source of genetic diversity.

The aim of this study was to evaluate the circadian rhythm of melatonin in horses, sheep, and goats, and to compare this rhythmicity under the same conditions. Five female thoroughbred, five female Sarda sheep, and five female Sarda goats were housed in boxes equipped with an opening window. Animals were kept under a natural photoperiod and indoor ambient temperature (16–20 °C). Blood samples were collected every 2 h over 48 h period. Results showed a circadian melatonin rhythm with a nocturnal acrophase in the three species studied. In sheep and goats, acrophase was observed at about 2 h before respect to horses. All species studied showed a high robustness between rhythm 61.20 ± 7.57 and 83.60 ± 7.26, denoting a high percentage of stationarity of melatonin circadian rhythm. However, we can claim that each species has its own characteristics in melatonin secretion that must be considered in the exploration of circadian clock in different species.

Florfenicol (FF) is employed in fish farms to contest or prevent bacterial infections. However, this pharmaceutical may produce reactive oxygen species that may cause biochemical changes in antibiotic-treated fish. The aim of this study was to evaluate the effect of FF on Rainbow Trout Oncorhynchus mykiss treated for 10 d with 7.5 and 15 mg/kg FF followed by a withdrawal period of 5 d. Superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, glutathione S-transferase, glyoxalase I and glyoxalase II, total glutathione, lactic dehydrogenase, and alkaline phosphatase were investigated in the livers of treated and untreated fish. A general impairment of antioxidant enzymes and metabolic indicators was measured in FF-treated Rainbow Trout. Onset of oxidative damage may have occurred during the antibiotic treatment as a consequence of the effect of FF toxicity at mainly the highest dose. Nevertheless, the rise in levels of total glutathione and glutathione S-transferase even after the withdrawal period may shield the antibiotic-mediated oxidative processes. Received December 22, 2015; accepted May 26, 2016.

This study aimed to describe the response variability of females silver eels in terms of gonad development and eggs production to standardized gonadotropic treatment (Carp pituitary extracts -CPE), and to relate this variability to population characteristics. For this purpose, sexual maturation, ovulation and fertilization were induced in two eel populations coming from different locations in Adriatic Sea (Comacchio -CM and Marano-Grado -MG lagoons), and after that, their reproductive capacity was valuated. External (Silver index -SI, Eye index –EI, Pectoral fin length index –PFLI, Condition factor -K) and hormonal (17β-estradiol -E2, testosterone -T) parameters were measured and some subject/group were sacrificed for histological and lipid analysis and age determination. Morphometric parameters showed the CM-Group to have highest values of Body weight (BW), Body length (BL) and K, while MG-Group presented highest PFLI and Gonadosomatic index (GSI) values. Regarding hormonal analysis, the CM-Group showed significantly higher T and E2 levels than the MG-Group, both groups showed considerably rapid increase at T5 (5th injection). A positive trend in gonadal development was found through histological evaluation; a more regular maturation was observed in the MG-Group whereas the CM-Group presented an exponential oocytes development starting from T10 (10th week), which led to an anticipated spawning. Lipid content showed significant differences in T0 (start study), post-ovulation and Control (30th week) between CM and MG eels. As to zootechnical performances, while MG eels released spontaneously into the water the CM’s were stripped in order to check ovulation. The MG eels were statistically the most productive with 40.1±6.33% BW of eggs released. Furthermore CM females ovulated mainly between the 19th and 22nd week (77.8% spawned eels) instead in the MG’s ovulation goes from the 24th to the 28th week (100% spawned eels). As fertilization is of concern, in both groups fertilized eggs were obtained with no difference in larvae production. These results seem to indicate that bigger dimensions, higher K and larger lipid content (Comacchio eels) could fasten gonadic maturation without positively influence reproductive performance of animals, both in term of quantity and quality of produced eggs. Smaller females with a highest SI (Marano-Grado eels) presented a more regular gonadic development, leading the animals to spontaneous spawning

Nonylphenol, an estrogenic-like compound, can induce vitellogenin synthesis in males and immature Teleostean species, but little is known about its effects on thyroid hormones balance. The present study evaluated the potential effects of a single acute exposure to nonylphenol (i.p. injected) on the thyroid and reproductive axis of 250 shubunkins (Carassius auratus). Plasma levels of thyroid hormones were quantified immunoenzymatically by ELISA assay. Nonylphenol induced a significant decrease of thyroxin levels, whereas no effect on triiodothyronine concentrations was detected. No histopathological changes were detected in thyroid or testes. The toxicological data confirmed that nonylphenol exerts an estrogenic effect on male fish. In addition, nonylphenol was suspected to inhibit the thyroid hormones balance, suggesting the thyroid should be included among the other endocrine glands susceptible to endocrine disruption.

The aim of this research was to investigate how growth hormone (GH) cortisol and some haematochemical parameters could be modified by the stress caused by the stages of shearing in Sarda breed sheep. Five groups of 10 sheep each were formed. Group A, only separated from the flock; Group B, only tied; Group C, both tied and shorn (animals in these three groups were ewe lambs shorn for the first time); Group D, adult females both tied and shorn; and Group E, adult entire males both tied and shorn (animals in these two groups had been shorn previously). Five blood samples were taken from each animal: the day before treatment (first sample); at the start of the treatment (second sample); in the middle of shearing for Groups C, D and E, 10 min after separation in Group A and 10 min after tying in Group B (third sample); at the end of treatment (fourth sample); and on the day after treatment (fifth sample). Plasma GH levels showed a decrease (P < 0.01) in Groups A, B, C and D during treatment (third and fourth samples), while Group E only at the end of shearing (fourth sample). In the third sample, the highest GH levels were recorded for Group E (P < 0.05), while it was recorded in the fourth sample for Groups A and E (P < 0.05). Cortisol levels showed a clear increase (P < 0.01) in all groups during treatment, but Group A showed a decrease in the fourth sample in comparison to the third sample. Males in the second, third and fourth sample and Group A only in the fourth sample showed lower cortisol levels when compared with the other groups (P < 0.05). Plasma glucose levels showed an increase (P < 0.01) in all groups during treatment but Groups B, C and E showed the highest values (P < 0.05). Magnesium (Mg) showed an increase in all groups in the third and fourth sample, while sodium (Na), in the same samples, only in Groups B, C and D. Potassium (K) values showed a significant decrease (P < 0.05) only in Groups C and D at the end of shearing. These results show that GH secretion is influenced by all the stress procedure: separation, tying and shearing. Shearing, even if necessary for animals, causes a significant change of the blood parameters involved in the stress response.

Contents Ghrelin, the endogenous ligand of the growth hormone (GH) secretagogue receptor, is considered a pleiotropic regulator involved in a large array of functions, including control of energy balance, regulation of food intake and, more recently, modulation of the reproductive axis. The present study was aimed at determining the changes in plasma concentrations of acyl-ghrelin in pregnant and lactating sows, with special emphasis on the relationship with the levels of GH, leptin, non-esterified fatty acids (NEFA) and insulin-like growth factor (IGF-1). Blood samples were collected via jugular venipuncture from 22 multiparous sow 30, 60 and 90 days after artificial insemination, 7 and 21 days after farrowing and at first oestrus post-weaning. Plasma concentrations of acyl-ghrelin, leptin, GH and IGF-1 were quantified by validated radioimmunoassay; NEFA were determined using a colorimetric procedure. Plasma acyl ghrelin levels were highest at 30 days of pregnancy and decreased thereafter and during lactation. At the beginning of lactation, GH, IGF-1 and NEFA concentrations significantly increased, while a significant reduction occurred in leptin. In conclusion, ghrelin concentrations in sow maternal circulation does not seem to play an important role in maintaining circulating GH levels during lactation; moreover, ghrelin is not associated with leptin, NEFA and IGF-1 levels.

The aim of the study was to investigate the daily pattern of melatonin during short photoperiods in sheep of different age. Thirty Sarda sheep kept under natural light conditions and divided into three equal groups were used: Group 1 (12–18 months); Group 2 (3–4 years); Group 3 (8–9 years). Blood samples were collected every 2 h for 22 h, starting at 21 December (12:00 h) until 22 December (10:00 h) for plasma melatonin radioimmunoassay determination. Statistical significant effect of time of day and age on melatonin concentration was registered. Mesor and amplitude values were statistically lower in Group 3 than in Groups 1 and 2. This study provides the first characterization of the relationship between age and daily pattern of melatonin in sheep, highlighting a decrease in melatonin production in the older animals.

The primary objective was to elucidate ovarian follicular dynamics and hormonal profiles in nulliparous heifer (HE; n = 11 ) and mixed-parity (MP; n=10 ) Mediterranean Italian water buffaloes (Bubalus bubalis) following an estrus synchronization protocol. Both groups received a progesterone releasing intravaginal device (PRID) implant for 10 days; a luteolytic dose of synthetic prostaglandin was given 7 days after PRID insertion. Daily ultrasound monitoring and collection of blood to determine plasma concentrations estradiol and progesterone started 1 day after PRID removal and lasted for 55 and 65 days in HE and MP buffaloes, respectively. Data analysis was restricted to the first 5 days after PRID removal and to one estrus cycle following induced ovulation. The HE buffaloes were not inseminated and only one ovulated within 5 days after PRID removal; the remainder ovulated between 8 and 48 days after PRID removal (except one in which ovulation was never detected). All HP buffaloes were inseminated 72, 96 and 120 h after PRID removal; seven buffaloes ovulated within 5 days after PRID removal and two were pregnant. Mean diameter of the largest follicle was significantly smaller in HE than MP buffaloes the first 4 days after PRID removal. There was a parity by time interaction ( P=0.0047 ) for plasma progesterone concentrations; progesterone was higher in HE than MP buffaloes 1 day after PRID removal, but the converse was true 2 days after PRID removal. After induced ovulation, HE buffaloes exhibited a one-wave ( n=5; length of cycle, 8-12 days), two-wave ( n=4; range: 20-26 days) or three-wave cycle ( n=1; 25 days). In contrast, all non-pregnant MP buffaloes ( n=8 ) had a two-wave cycle (range: 19-25 days). For buffaloes with two-wave cycles, the growth rate and diameter of the largest follicle was significantly smaller in HE than MP buffaloes for both the first follicular wave (1.3mm versus 1.7 mm per day and 10.5 mm versus 13.3 mm, respectively) and the second follicular wave (1.0 mm versus 1.3 mm per day and 11.0 mm versus 13.8 mm). In conclusion, there were many significant morphological and endocrine differences between HE and MP buffaloes.

European eels live most of their lives in freshwater until spawning migration to the Sargasso Sea. During seawater adaptation, eels modify their physiology, and their digestive system adapts to the new environment, drinking salt water to compensate for the continuous water loss. In that period, eels stop feeding until spawning. Thus, the eel represents a unique model to understand the adaptive changes of the enteric nervous system (ENS) to modified salinity and starvation. To this purpose, we assessed and compared the enteric neuronal density in the cranial portion of the intestine of freshwater eels (control), lagoon eels captured in brackish water before their migration to the Sargasso Sea (T0), and starved seawater eels hormonally induced to sexual maturity (T18; 18 weeks of starvation and treatment with standardized carp pituitary extract). Furthermore, we analyzed the modification of intestinal neuronal density of hormonally untreated eels during prolonged starvation (10 weeks) in seawater and freshwater. The density of myenteric (MP) and submucosal plexus (SMP) HuC/D-immunoreactive (Hu-IR) neurons was assessed in wholemount preparations and cryosections. The number of MP and SMP HuC/D-IR neurons progressively increased from the freshwater to the salty water habitat (control > T0 > T18; P < 0.05). Compared with freshwater eels, the number of MP and SMP HuC/ D-IR neurons significantly increased (P < 0.05) in the intestine of starved untreated salt water eels. In conclusion, high salinity evokes enteric neuroplasticity as indicated by the increasing number of HuC/D-IR MP and SMP neurons, a mechanism likely contributing to maintaining the body homeostasis of this fish in extreme conditions.

Daidzein, an isoflavone abundant in soybeans and other legumes, displays estrogen like properties. This study was aimed at evaluating the effect of daidzein (1 and 10 M ) on nuclear and cytoplasmic maturation of pig oocytes and on steroidogenic activity of cumulus cells. Daidzein supplementation during IVM had no effect on nuclear maturation and on fertilization traits. By contrast, both concentrations significantly (P < 0.05) inhibited progesterone production by cumulus cells after 24 and 48 h of culture while they did not induce any effect on estradiol production. Furthermore, daidzein did not exert any effect on the percentage of embryos that developed to blastocyst stage, on the number of blastomeres per blastocyst, or on the level of Hsp-70 and -90 gene transcript. Overall, our data demonstrate that daidzein added during oocyte maturation does not affect pig embryo development even if it markedly inhibits progesterone production by cumulus cells. Further studies are needed to evaluate the possible effect of daidzein during embryonic development.

The aim of this study was the investigation of hormonal and ovarian follicular dynamics in prepuberal buffaloes (Bubalus bubalis) bred in Italy. Eleven 5-9-month old buffalo calves ranging in weight from 122 to 270kg, maintained under controlled nutritional and environmental conditions, underwent 50 days of ultrasonographic ovarian follicular monitoring in the months of October-December. Blood sampling for E(2) and FSH determination and ultrasonographic monitoring using a 7.5MHz linear probe and an ALOKA SSD-500 monitor were performed daily. No differences in any of the parameters under study were highlighted when calves were divided into two weight categories (200 and200kg) and thus data were pooled. In this study, values are reported as mean+/-S.D. A range of two-six regular follicular waves was reported among calves with an average of 4+/-1.1. Overall interval (days) between wave emergence was 9.9+/-2.8 and largest diameters (mm) of dominant and first subordinate follicles were 8.4+/-1.2 and 4.8+/-0.6, respectively (P0.05). With the exception of one calf, some minor follicular waves (short waves or SWs; 1.6+/-1), lasting10 days (6.1+/-1.2) were reported. They were monitored contemporaneously on the ovary contralateral (n=7) or ipsilateral (n=3) to the main follicular wave. Growth rate (mm per day) of dominant follicles (DF) was significantly faster than for corresponding subordinate follicles (SF) and follicles of SWs (1.08+/-0.2 versus 0.79+/-0.1 and 0.83+/-0.1, respectively, P0.05). The static phase (days) lasted longer in DF compared to SF and SW (5.4+/-1.8 versus 2.4+/-1.2 and 2.6+/-1, respectively, P0.05). The regressing phase (mm per day) was similar among DF, SF and SW (0.86+/-0.2, 0.94+/-0.2 and 0.84+/-0.1, respectively, P=0.09). Episodic spikes of E(2) and FSH were reported, corresponding to wave development throughout the course of investigation. In conclusion, the majority of buffalo calves displayed a typical pattern of regular follicular development in conjunction with a dynamic trend of ovarian and hypophyseal hormones. Some minor follicle turnover was reported with parallel main follicular waves.

Il Florfenicolo (FF), analogo fluorinato sintetico di Tiamfenicolo e Cloramfenicolo (CA), è un antibiotico ad ampio spettro molto utilizzato in acquacoltura. Nonostante la sua efficacia sia pari a quella del CA, rispetto a quest’ultimo, esercita una più bassa tossicità nei confronti dell’organismo sottoposto a terapia antibiotica, per l’assenza del nitrogruppo. Notoriamente gli antibiotici possono provocare fotosensibilizzazione: un eventuale effetto fototossico di questi composti è mediato, a livello cellulare, anche da una maggiore produzione di radicali liberi e radicali dell’ossigeno. L’aumento della concentrazione di radicali liberi può causare una condizione di stress ossidativo nell’organismo. Obiettivo è la valutazione di biomarkers di stress ossidativo, glutatione S-transferasi, glutatione reduttasi e concentrazione di glutatione totale, livelli residuali nel fegato e livelli dell’ormone tiroideo triiodotironina nel sangue di trota iridea alimentati per dieci giorni con due diete medicate con FF (7,5 e 15 mg/kg). La dose raccomandata per il florfenicolo in acquacoltura è 10 mg/kg per pesce per 10 giorni. Le due diete sperimentali sono state preparate a partire da un mangime commerciale per pesci di allevamento (controllo), a cui è stata aggiunta una premiscela commerciale di florfenicolo (Nuflor, 40 mg/g). Dopo l’acclimatazione, gli esemplari di trota iridea sono stati divisi in due gruppi sperimentali, di cui il primo esposto all’irradiazione di lampade solari per 12 ore al giorno, mentre l’altro è stato mantenuto in una condizione di costante ombreggiatura. Tra gli esemplari sottoposti a condizioni di irradiazione solare e quelli all’ombra, sono state evidenziate differenze di risposta sia per quanto riguarda i livelli residuali che per gli indici biochimici indagati. I livelli residuali erano più alti nelle trote mantenute in condizioni di irradiazione solare rispetto a quelle in condizioni di ombreggiatura. Livelli più bassi dell’ormone tiroideo T3 sono stati evidenziati nel gruppo trattato con un alto dosaggio di farmaco in condizioni di ombreggiamento ed in tutti e due i gruppi trattati con FF e mantenuti in condizioni di luce artificiale. La valutazione dei biomarkers di stress ossidativo ha indicato una più marcata condizione di stress ossidativo negli esemplari di trota iridea trattati con l’antibiotico e sottoposti ad irradiazione solare, come conseguenza di un potenziamento dell’effetto tossico dovuto all’azione combinata di ambedue i fattori. Infatti, sebbene l’effetto proossidante del FF, alle due dosi testate, sia stato evidente in ambedue i gruppi sperimentali, esso era più rilevante in condizioni di irradiazione solare, rispetto a quelle di costante ombreggiatura

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.