1,721,106 research outputs found

    Use of a synthetic GnRH analog to induce reproductive activity in Canaries (Serinus canaria)

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    In this study, we evaluated the effects of a transcutaneously administered gonadotropin-releasing hormone analog (lecirelin) on the reproductive activity of the canary (Serinus canaria). Two groups of 20 pairs of canaries were treated with increasing concentrations of lecirelin delivered in a cream vehicle; one group was exposed to a natural photoperiod, and the other group received additional photostimulation. Two groups of 10 pairs of canaries served as controls; one group was exposed to an artificially lengthened photoperiod, and the other group was maintained under a natural photoperiod and treated with a nonmedicated cream vehicle. In all canaries treated with lecirelin, the onset of reproductive activity occurred significantly earlier than in either control group.[...

    Effectiveness of a modified administration protocol for the medical treatment of canine pyometra

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    Pyometra is one of the most common diseases in intact bitches. The aim of this study was to evaluate the effectiveness of a modified aglepristone protocol for the medical treatment of pyometra in the bitch. Of these, 73 bitches affected by pyometra of different breeds and age (2–14 years old) were enrolled. They were randomly assigned to a control group (CTG - 26 bitches) treated with classical protocol (aglepristone at 0, 1 and 6 days - day 0 = day of the diagnosis) and a modified treated group (MTG - 47 bitches) treated with a different administration protocol (aglepristone at 0, 2, 5 and 8 days). The classical protocol with the anti-progestagen aglepristone was effective in 88.5 % (23/26) of CTG bitches while the modified protocol was effective in all (47/47) of MTG bitches. One of the 23 CTG bitches received a further administration on day 14, which resolved the pyometra, while in the three cases of CTG bitches, in which the treatment was ineffective, an ovariohysterectomy was carried out. The modified protocol showed a success rate of 100 %, compared with the classical protocol proposed in the literature, and no recurrence of the disease was recorded in the 24 months follow up. After treatment, the oestrus onset was earlier than expected (interoestrus of 128 ± 32 days). In this study, the modified treatment protocol showed high efficacy and lack of recurrence within 24 months, suggesting a complete recovery of reproductive function in the bitch, with a normal fertility

    The effect of GnRH on in vitro bovine myometrial activity

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    The aim of this study was to evaluate, in vitro, the effects of increasing concentrations of GnRH on spontaneous mechanical activity patterns of uterine smooth muscle preparations of cows during the follicular and the luteal phases of the oestrus cycle. Uterine smooth muscle strips from 14 cows in follicular and 9 in luteal phase were collected immediately after slaughter and processed within 60 min from collection. Two strips of the same uterus were mounted in an isolated organ bath with two chambers to evaluate the role of decapeptide GnRH on spontaneous myometrial contractility. After equilibration period at 20 mN resting tension, the mechanical activity of the uterus was recorded for 10 min and the mean contractile force (MCF) was calculated. Then GnRH antagonist (antide) was added to one chamber at fixed concentration (10(-4)mol) and allowed to diffuse in solution and make contact with the strips. Subsequently, GnRH was added to the two baths at the same time at increasing concentration and MCF was recorded for 10 min. The effect of GnRH on spontaneous myometrial activity was evident only in the strips from subjects in follicular phase. Our results are suggestive of the presence of GnRH receptors in bovine myometrial tissue. The involvement of GnRH on uterine contractions at mating can be postulated

    Effect of sperm concentration on characteristics of frozen-thawed semen in donkeys

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    In this study, the effect of donkey sperm concentration in the straw during cryopreservationon the quality of thawed semen was evaluated. Samples from seven adult Martina Francajackasses were collected three times using a Missouri artificial vagina. After estimation ofvolume and concentration, raw semen was evaluated for motility using a computer-assistedsperm analyzer (CASA); viability and acrosome integrity were also determined. Fresh semenwas then centrifuged and re-suspended at five different concentrations (100, 250, 500,750, and 1000×106 sperm/ml) with a commercial extender, packaged in 0.5 ml straws, andfrozen. After thawing, motility parameters, viability, and acrosome integrity were analyzed.The analysis of the data showed similar parameters of fresh semen compared with those ofcentrifuged and cooled samples. The sperm concentration in the straw affected the semenparameters analyzed after thawing, as suggested by evidence that when the concentrationincreased, the quality of the post-thawed semen decreased. Furthermore, the differencesin total and progressive motility among samples at different concentrations are due to theimmobilization of spermatozoa, as suggested by the finding that the percentage of staticspermatozoa increased when the concentration increased. The reason for the impairmentof semen quality when the sperm concentration increased was discussed. A great variabilityin cryo-resistance was found between jackasses but not within the same male, suggestingthe presence of donkey males with semen that has acceptable and unacceptable freezingqualities.[...
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