Sperm parameters and testicular volumes in Saguinus mystax

Adult male Saguinus mystax tamarins were evaluated for sperm parameters and testicular volumes. Sperm concentrations average 195.5 X 10(6)/cc with 41.7% motile sperm. Semen specimens were classified as normal, relative to sperm morphology, when 95% or more of the sperm in the specimen had normal morphology; 76% of the animals evaluated had normal semen specimens using this criterion. Testicular volumes averaged 726.9 mm3. A total of 50 infants were sired by 16 of these males during the period covered by this report.     

Use of oxytocin and cloprostenol to facilitate semen collection by electroejaculation or transrectal massage in bulls

Two experiments were conducted with 24 bulls in which semen collection was attempted by transrectal massage (RM) and electroejaculation (EE). In experiment 1, bulls received the following treatments on successive semen collection days: saline 10 min prior to electroejaculation (control); saline 10 min prior to 2 min of transrectal massage followed by electroejaculation; cloprostenol (CLO) 10 min prior to 2 min of transrectal massage followed by electroejaculation; oxytocin (OXY) 10 min prior to 2 min of transrectal massage followed by electroejaculation. Transrectal massage consisted of general, back and forth motion over the ampullae, prostate and urethra with a flattened hand.

In experiment 2, bulls received saline (control), oxytocin, or cloprostenol 10 min before attempting semen collection by transrectal massage. Massage was applied specifically to the ampullae for a maximum of 5 min or until a semen sample was obtained. Electroejaculation was attempted in all bulls following transrectal massage.

In experiment 1, semen was obtained in <1% of bulls by transrectal massage. However, by using an improved massage technique in experiment 2, semen was obtained in 97.2% of attempts. Semen was obtained in 96.9 and 98.9% of attempts by electroejaculation in experiments 1 and 2, respectively.

Oxytocin treatment increased the time to penile protrusion during electroejaculation in experiment 1 and during massage in experiment 2. In experiment 1, oxytocin decreased the time to semen emission and tended to decrease the number of electroejaculation stimuli to semen emission. Cloprostenol treatment, in experiment 1, resulted in an increased number of electroejaculation stimuli to penile protrusion, but did not affect the number of stimuli required for semen emission.

Massage of the ampullae prior to electroejaculation reduced both the time to semen emission and the number of electroejaculation stimuli required for semen emission. Transrectal massage of the ampullae was very effective in this experiment for producing semen emission, but quantity of semen samples was less than for electroejaculation. The usefulness of transrectal massage for semen collection in breeding soundness evaluations needs to be investigated further under field conditions.     

Seasonal variation in serum testosterone, testicular volume and semen characteristics in coatis (Nasua nasua)

The objective was to characterize seasonal changes in serum testosterone concentration, testicular volume and sperm quantity and quality in captive coatis (Nasua nasua) from Pantanal, MT, Brazil. Sampling was done once monthly for 1 y. Mean (± SEM) serum testosterone concentrations (767.37 ± 216.2 ng/ml) and total and progressive sperm motility (79.6 ± 3.9%; 3.8 ± 0.3, on a scale of 0 to 5) peaked in July. The highest combined testis volume (10.3 ± 0.4 cm³) and sperm concentration (403 million ± 102 sperm/ml) occurred in August, at the peak of the winter breeding season. No seasonal effects on percentages of morphologically normal sperm, acrosome integrity, or live sperm were detected; however, the percentage of secondary sperm defects was higher in the winter. In conclusion, intricate relationships between testosterone concentration, testis volume, semen concentration and total and progressive sperm motility with high levels of breeding activity were observed during the dry season in the winter (June, July, August), followed by a subsequent decline in these activities during the wet season (i.e., summer: December, January, February). There was no seasonal pattern for production of functionally intact and morphologically normal sperm.     

Evaluation of anesthetic protocol for the collection of semen from captive collared peccaries (Tayassu tajacu) by electroejaculation

The objective of this study is to verify and compare the effects of acepromazine–tiletamine–zolazepam and propofol used in anesthetic protocols for semen collection by electroejaculation from captive collared peccaries. Ten sexually mature animals were physically restrained and anesthetized by either intravenous administration of tiletamine–zolazepam (2 mg/kg) after acepromazine premedication, or a propofol dose of 5 mg/kg. The onset of anesthetic recovery was determined by the animals regaining consciousness and attempting to stand. Semen was collected by electroejaculation and evaluated for volume, pH, sperm concentration, progressive motility, morphology, percentage of live cells and functional membrane integrity. Six anesthetized animals with the acepromazine–tiletamine–zolazepam protocol showed erection, but semen could be collected in only four (40%) attempts. Of the animals anesthetized using propofol, nine showed erection, and the ejaculates were collected in eight (80%) attempts. Furthermore, propofol afforded rapid recovery of animals, and ejaculates with enhanced sperm motility and functional membrane integrity as compared with those collected by the other protocol (P < 0.05). In conclusion, use of propofol for anesthetic restraint of collared peccaries enhanced collection of semen by electroejaculation.     

Cryopreservation of Iberian red deer (Cervus elaphus hispanicus) spermatozoa obtained by electroejaculation

We tested extenders and freezing protocols for Iberian red deer semen. Samples were obtained by electroejaculation (10 stags), and analyzed for motility (CASA), viability (propidium ioide), acrosomal (PNA-FITC) and mitochondrial status (JC-1). Samples were diluted 1+1 in extender, cooled and adjusted for glycerol (extender with higher glycerol concentration), brought to 160×10⁶ mL⁻¹ and frozen. Four experiments were carried out, repeating sperm analysis after thawing to compare treatments. In a first experiment, seven samples were frozen using Triladyl^® (20% egg yolk) and UL extender (Tes-Tris-fructose, 15% egg yolk, 4% glycerol). Triladyl^® yielded higher motility after thawing. In a second trial, 17 samples were frozen using Triladyl^®, Andromed^®, Bioxcell^®, and UL with 8% LDL (low-density lipoproteins). Triladyl^® and Andromed^® performed better than Bioxcell^® on motility, and than UL-LDL on viability and acrosomal status. In a third experiment, the performance of freezing the sperm-rich ejaculate fraction versus the whole ejaculate was tested on nine samples. The sperm-rich ejaculate fraction not only rendered more motile and viable spermatozoa but also showed higher freezability (higher motile spermatozoa recovery). In a fourth experiment, we tried three modifications of the freezing protocol, for improving the freezability of low concentration samples: prior removal of seminal plasma; replacing extender (second fraction) for pure glycerol to reduce dilution; and performing only the 1+1 dilution, not the second dilution. No differences were found, although only three samples could be used. Both Triladyl^® and Andromed^® were deemed appropriate for freezing Iberian red deer semen, and the rich fraction should be selected for freezing.     

Use of two anesthetic combinations for semen collection by electroejaculation from captive coatis (Nasua nasua)

The objective was to compare the effects of ketamine-xylazine or tiletamine-zolazepam combinations as anesthetic protocols for captive coatis (Nasua nasua) for semen collection by electroejaculation. Five mature male coatis were physically restrained and then anesthetized by im injections of ketamine (10 mg/kg) plus xylazine (1 mg/kg) or a tiletamine-zolazepam combination (8 mg/kg). For the two combinations, additional quarter-doses of ketamine or the tiletamine-zolazepam combination were administered when necessary. Semen was collected by electroejaculation and immediately evaluated for color, volume, pH, sperm motility, vigor, morphology, acrosomal integrity, and percentage of live cells. Overall, collection of nine ejaculates was attempted from five animals for each treatment. Regardless of the anesthetic combination, all animals developed an erection during each attempt to collect semen. Ejaculates were obtained in all (9 of 9) attempts that used ketamine-xylazine for anesthesia, but in only 3 of 9 attempts (P < 0.05) when tiletamine-zolazepam was used. All ejaculates contained sperm, with no significant differences in semen characteristics between the two anesthetic combinations. Recovery was smooth in all animals. In conclusion, semen collection by electroejaculation in coatis was significantly more successful with the use of a ketamine-xylazine combination than with tiletamine-zolazepam.     

一种改进的阴茎电刺激采精法和猕猴藏酋猴及熊猴的采精及其精液特征的初步研究

本文报道了一种改进的阴茎电刺激采精法,用脱脂棉和铝箔作为电极,以避免直接用金属电极可能对阴茎的损伤,并运用这一方法对猕猴（Ｍａｃａｃａｍｕｌａｔｔａ）、藏酋猴（Ｍ．ｔｈｉｂｅｔａｎａ）和熊猴（Ｍ．ａｓｓａｍｅｎｓｉｓ）进行了电刺激采精及其精液特征研究。电刺激采精模式为连续刺激和间断刺激方式。在采精过程中没有发生阴茎损伤。对初次接受电刺激采精的动物以间断刺激模式效果较好。猕猴、藏酋猴和熊猴的射精体积分别为２．０±０．１、６．３±１．１和３．２±０．６ｍｌ;液化体积分别为０．７±０．６、２．１±０．４和１．７±０．３ｍｌ;精子浓度分别为１２．６±１．２×１０~８、４５．６±５．６×１０~８和１１．５±０．９×１０~８／ｍｌ。３种动物精液的液化率分别为：猕猴３６．２±０．９％,藏酋猴３４．０±１．４％;熊猴５１．８±１．２％。３种动物的精子总数与射精体积和凝块体积没有相关性（ｒ~２＝０．０７９;０．０１６;０．０９４和ｒ~２＝０．０６４;０．０２０;０．０７２）。上述结果表明：１）改进的阴茎电刺激采精法适用于猕猴,特别是阴茎表面较为粗糙的藏酋猴和熊猴;２）藏酋猴的射精体积和精子总数是迄今已报道的非人灵长类中最大的,可能     

Collection and evaluation of semen from the three-toed sloth (Bradypus tridactylus)

Sloths (Bradypus sp.) are extremely sensitive animals that suffer with the destruction and fragmentation of forests. They present a low population growth rate and need to be further studied for the preservation of the specie. Thus, the aim of this study was to establish an efficient semen collection protocol as well as characterize sperm concentration, motility and morphology in order to contribute with information about the reproductive traits of this specie, which has never been described in the literature before. For that, nine Bradypus tridactylus males were captured during the wet season and six during the dry season, in Manaus (AM), located in the north region of Brazil, semen was collected by electroejaculation with shocks given in sequences of progressive intensities (minimum 20 mA and maximum 60 mA). All animals ejaculated small volumes of semen and in some of them, the volume ejaculated was not enough for a complete spermiogram. Physical characteristics observed on the collections of the wet season were different from those seen in the specimen collected in the dry season. Motility an vigor was very low and did not show forward progression, only oscillatory movement. After Spermac stain, spermatozoa presented a wide variety of defects; however, the differences in morphology were not significant between seasons. The morphology assessed by scanning electron microscopy shows that the head in both groups could be elongated, short or could have a base narrower than the apex and the midpiece narrowed abruptly, forming a nip in its transition to the tail. Although further studies are necessary to verify our preliminary findings concerning seasonal variation in sperm quality, these results demonstrate that semen can be safely collected from sloths by electroejaculation and provide the first reports of semen characteristics in this species.     

Alkaline phosphatase as an indicator of true ejaculation in the rhinoceros

The objective was to determine if seminal alkaline phosphatase (ALP) can serve as an indicator of true ejaculation in the rhinoceros. Concentrations of ALP activity were determined in seminal fractions collected from African black rhinos (Diceros bicornis), an African white rhino (Ceratotherium simum), and an Indian rhino (Rhinoceros unicornis) during electroejaculation. In addition, seminal fractions collected during penile massage of a Sumatran rhino (Dicerorhinus sumatrensis) were assessed. Correlations between ALP activity and sperm concentration, fraction pH, and fraction osmolality were evaluated in the Indian rhino and black rhino. Concentrations of ALP activity in rhino ejaculate fractions ranged from < 5 to 11,780 U/L and were positively correlated (P < 0.05) with sperm concentration for both Indian rhino (r = 0.995) and black rhino (r = 0.697), but did not exhibit a strong correlation with either pH or osmolality (P > 0.05). Data were insufficient for establishing meaningful correlation coefficients in the Sumatran rhino and white rhino, but preliminary results were in accordance with findings in the Indian rhino and black rhino. We concluded that ALP was present in rhinoceros semen, likely originated from the epididymides and/or testes, and could serve as a useful tool for assessing the production of ejaculatory versus pre-ejaculatory fluid in the rhinoceros.     

The influence of washing Spanish ibex (Capra pyrenaica) sperm on the effects of cryopreservation in dependency of the photoperiod

Extenders containing low concentrations of egg yolk are recommended for cryopreserving ibex spermatozoa. However, the phylogenetic relationship of the Spanish ibex (Capra pyrenaica) with domestic goats suggests that phospholipases in the seminal plasma may have a negative effect on the response to freezing-thawing when egg yolk-based diluents are employed. The aim of the current work was to determine how seminal plasma removal from Spanish ibex semen, collected by electroejaculation over a period of 1 yr, affects its response to freezing-thawing. Semen was collected from six adult ibexes maintained in captivity. The negative effects of freezing-thawing on the quality of sperm motility and on the integrity of the acrosome and plasma membrane were more serious in the nonwashed semen samples than in those from which the seminal plasma had been removed (P < 0.01, P < 0.05, and P < 0.05 respectively). The beneficial effect of removing the seminal plasma was particularly noticeable during the time of decreasing photoperiod. This suggests that ibex semen shows increased phospholipase activity during the rutting season.