Albamaria Parmeggiani

Fatty acid composition of eggs and its relationships to egg and larval viability from domesticated common sole (Solea solea) breeders.

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.

Seasons induce changes in the daily rhythm of plasma melatonin in goats (Capra hircus)

To evaluate the influence of natural photoperiod on the daily rhythm of melatonin, we assessed melatonin plasma concentration at four different times of the year. Ten Sarda breed goats were led to the natural pasture during the day and were kept in a common stall during the night. Blood samples were collected by means of a cannula inserted into the jugular vein, every two hours for a 24-hour period during the vernal equinox, summer solstice, autumn equinox, and winter solstice. Our results showed the existence of clear seasonal variation in the daily rhythm of plasma melatonin in goats, with the highest MESOR value in winter followed by spring. Acrophase was always observed in the middle of the scotophase. Robustness of the rhythm was higher in the spring as compared to the winter. Our results showed a daily rhythm of plasma melatonin concentration strongly related to the seasons. These results could be useful to establish appropriately timed melatonin and/or photoperiod treatments for the management of reproductive physiology in goats.

Assessment of Detoxifying Markers for Florfenicol in Rainbow Trout Liver

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.

Melatonin circadian rhythm in three livestock species maintained in the same housed conditions

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.

Enteric neuroplasticity in seawater-adapted European eel (Anguilla anguilla).

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.

Lactation influences the serum level of leptin and growth hormone during the daily bathyphase in ewes

Abstract 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 (<900 g/day). From the 5th to the 110th day after lambing, every 15 days, body condition score (BCS) was recorded and milk samples were collected. At the same data point, blood sampling was performed and leptin, GH and, Non-Esterified Fatty Acids (NEFA) were assessed. On milk, fat and proteins were determined. Statistical differences were observed in BCS, leptin, GH, NEFA and fat concentration in milk between the two groups. BCS was lower in high group and decreased from the 20th to the 90th day of lactation. Leptin was higher in low group and increased from the 50th and the 65th day of lactation, in low and high groups, respectively. GH and NEFA were higher in high group and decreased from the mild lactation. In high group, BCS and milk yield were negatively correlated and leptin was negatively correlated with GH and NEFA. In low group, leptin was positively correlated with BCS and negatively correlated with the all studied parameters. GH and NEFA were positively correlated with both groups. In conclusion, milk yield had an effect on the leptin and GH plasma values recorded during their bathyphase.