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Contributo alla conoscenza della distribuzione dell'innervazione simpatica nei prestomaci di ovino
No full textConcentrazione ematica della malatonina in capre di razza Maltese e Siriana
No full textMelatonin blood levels in Maltese and Syrian goats. The melatonin blood concentration has been studied on 10 adult goats of two southern Italian breeds (5 Maltese and 5 Syrian), which are characterized by a weak reproductive seasonality, presenting a spring breeding period in addition to the main autumn season. The animals were kept under natural photoperiod, were bred in autumn and displayed regular deliveries and lactations. The plasma melatonin concentration was assayed by RIA on blood samples taken at 2 h interval for 24 h. Night samples were taken in dim red light. The sampling sessions were repeated at 2 months interval for one year. During the daylight period the hormone levels were very low (< 4 pg/ml), while during night time in each sampling session the concentrations arised in all the animals, with high individual variability (the individual mean night levels ± SE ranged from 6.41.9 to 109.162.4 pg/ml). Each animal maintained during the year higher or lower nocturnal melatonin levels in comparison to those of the other goats, and significant (P<0.05) differences in the night mean values between the animals have been found. The Syrian goats showed lower (P<0.05) mean night levels (20.052.30) than the Maltese ones (55.349.23 pg/ml), two goats with the higher mean values being Maltese. No significant seasonal differences in the mean melatonin nocturnal levels resulted from our data: the lowest mean night values were recorded in Aug, the highest in Oct. . It would be interesting to investigate if the significant individual variability in nocturnal melatonin plasma concentrations found in the present work might be someway linked to individual variability in the parameters of the reproductive seasonality
Plasma total T3 and T4 concentrations in bucks as affected by photoperiod
No full textAbstract
In order to determine whether total thyroxine (T4) and 3-3_-5-triiodothyronine (T3) plasma concentrations are affected by photoperiodic changes in bucks, these hormones were assayed using RIA in samples collected weekly for a year period in Alpine and Saanen male goats exposed to natural photoperiod (46◦N latitude, control group), or to artificial photoperiod alternating every 2 months (4M group) or 1 month (2M) with long days (16L:8D) and short days (8L:16D). In the control group, the thyroid hormones showed marked seasonal variation. Maximal monthly peaks were recorded at the beginning of spring (April) for plasma T4 (35.7±1.8 ng/ml) and in late winter to early spring (March) for plasma T3 (0.91±0.11 ng/ml)—with the lowest concentrations being recorded in October (autumn) for plasma T4 (22.8±1.0 ng/ml) and in September (late summer to early autumn) for plasma T3 (0.42±0.01 ng/ml). In the 4M group, T4 plasma concentrations varied with daylength (p < 0.05), recording an overall mean concentration significantly (p < 0.01) higher during the short days (37.3±7.5 ng/ml), than during long days (32.2±7.3 ng/ml) with a significant effect of sampling time within each photoperiod (p < 0.0001). In both lighttreated groups, T3 varied with photoperiod (p < 0.0001) and time (p < 0.0001), increasing during long days and decreasing during short days. T3 plasma concentrations (derived from peripheral monodeiodination) followed the photoperiodic changes, while it was hypothesized that the stimulatory effect of daylength on T4 (thyroid gland secretory activity) was characterized by a longer latency period and could be seen in the 4M group during the following photoperiodic treatment. It is concluded that photoperiod affects thyroid hormone plasma concentrations in male goats, since different lighting regimes resulted in different profiles of both plasma T3 and T4. Bearing in mind the pivotal role of thyroid hormones in stimulating the metabolic activity of the whole body, it is possible that the light-induced increase in circulating hormones could sustain and improve animal production. The suitability of supplementary light treatments needs to be considered.
© 2005 Elsevier B.V. All rights reserved.
Keywords: Goats; Thyroid hormones; Season; Photoperio
Progesterone Plus PMSG Priming in seasonally Anovulatory Lactating sarda ewes Exposed to the Ram Effect
No full textThe aim of this trial was to evaluate the effectiveness (fertility and lambing) of priming with a single injection of progesterone plus PMSG in anovulatory lactating Sarda ewes subjected to the ram effect (RE) in spring. Thirty ewes (P4 group) were i.m. injected with 30 mg progesterone and 500 IU PMSG 36 h before ram introduction (d 0). This treatment was compared to a 12-day treatment with fluorogestone acetate intravaginal sponges that was followed by injections of 350 IU PMSG upon sponge withdrawal (FGA group, n=30). All ewes responded to RE, showing plasma progestrone concentrations >1 ng/mL between d 6 and 12 (FGA) or 6 and 9 (P4). Eighty-nine percent of the P4 ewes conceived at first ovulation, and 11% conceived following a short estrus cycle. Lambings occurred on d 150.4 +/- 3.9, and the lambing rate was 100%. The fertility of the FGA ewes was 83% for the induced ovulation and was 7% for the second ovulation after a normal cycle. The FGA ewes lambed on d 149.8 +/- 4.4, and the lambing rate was 83%. Two abortions were recorded for the FGA ewes, which had higher prolificacy than the P4 group (2.2 +/- 0.8 vs. 1.8 +/- 0.4, respectively; P<0.05). Both fertility and the lambing rate were high in both groups, with a high degree of estrus synchronization, and there were no significant differences between the groups. We concluded that priming of lactating Sarda ewes in spring with P4+PMSG before RE is an effective and competitive method (cheaper and more practical than FGA+PMSG) of inducing fertile ovulations in these ewes
Plasma thyroxine and 3-3’-5’ triiodothyronine annual trends in male goats are affected by short photoperiodic cycles.
No full textLa poligrafia dinamica: una nuova tecnica per l’oggettiva valutazione di parametri fisiologici ed etologici
No full textProgesterone plus PMSG priming in seasonally anovulatory lactating Sarda ewes exposed to the ram effect
No full textThe aim of this trial was to evaluate the effectiveness (fertility and lambing) of priming with a single injection of progesterone plus PMSG in anovulatory lactating Sarda ewes subjected to the ram effect (RE) in spring. Thirty ewes (P4 group) were i.m. injected with 30 mg progesterone and 500 IU PMSG 36 h before ram introduction (d 0). This treatment was compared to a 12-day treatment with fluorogestone acetate intravaginal sponges that was followed by injections of 350 IU PMSG upon sponge withdrawal (FGA group, n = 30). All ewes responded to RE, showing plasma progestrone concentrations > 1 ng/mL between d 6 and 12 (FGA) or 6 and 9 (P4). Eighty-nine percent of the P4 ewes conceived at first ovulation, and 11% conceived following a short estrus cycle. Lambings occurred on d 150.4±3.9, and the lambing rate was 100%. The fertility of the FGA ewes was 83% for the induced ovulation and was 7% for the second ovulation after a normal cycle. The FGA ewes lambed on d 149.8±4.4, and the lambing rate was 83%. Two abortions were recorded for the FGA ewes, which had higher prolificacy than the P4 group (2.2 ± 0.8 vs. 1.8 ± 0.4, respectively; P<0.05). Both fertility and the lambing rate were high in both groups, with a high degree of estrus synchronization, and there were no significant differences between the groups. We concluded that priming of lactating Sarda ewes in spring with P4+PMSG before RE is an effective and competitive method (cheaper and more practical than FGA+PMSG) of inducing fertile ovulations in these ewes.
Key words: Estrus induction, Fertility, Progesterone priming, Prolificacy, Sheep
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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