No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Improving the Efficiency of the Preliminary Electroejaculation Technique Developed for Semen Collection from the Agouti (Dasyprocta leporina)
Abstract
This study tested various combinations of ketamine and xylazine with the objective to improve on the efficiency of the preliminary electroejaculation technique developed for semen collection from the agouti (Dasyprocta leporina). There were two experiments, which were each replicated. Experiment 1 had six treatments: treatment 1 (30 mg/kg ketamine and 10 mg/kg xylazine), treatment 2 (20 mg/kg ketamine and 10 mg/kg xylazine), treatment 3 (30 mg/kg ketamine and 5 mg/kg xylazine), treatment 4 (20 mg/kg xylazine), treatment 5 (30 mg/kg xylazine), and treatment 6 (40 mg/kg xylazine). Experiment 2 included five treatments: treatment 7 (40 mg/kg xylazine), treatment 8 (20 mg/kg ketamine and 40 mg/kg xylazine), treatment 9 (15 mg/kg ketamine and 40 mg/kg xylazine), treatment 10 (10 mg/kg ketamine and 40 mg/kg xylazine), and treatment 11 (5 mg/kg ketamine and 40 mg/ kg xylazine). Mean induction times were 3:27 +/- 0:31 and 4:59 +/- 0.49; mean immobilization times were 1:55 +/- 0.11 and 1:19:06 +/- 0:11.7 hr, respectively, for experiments 1 and 2. Treatment 4 produced the best ejaculation time and semen volume, 4.53 +/- 0.52 min and 0.41 +/- 0.07 ml, respectively. Spermatozoa were observed in 75% of ejaculate samples collected when treatments 6 and 7 were applied. The best treatments were 6 and 7 (P < 0.05); spermatozoa concentration (431 +/- 180 x 106/ml), motile cell % (47.17 +/- 8.78%) and forward progressive motility % (47.1 +/- 10.5%). Success rates for samples containing spermatozoa increased from 30% in previous experiments to 41.33%. It was concluded that weaker dosages of xylazine may require being administered in combination with ketamine to completely anaesthetize the male agouti for electroejaculation.
... This line of research also included semen collection by electroejaculation (EE) from Dasyprocta leporina and Dasyprocta azarae in the Republic of Trinidad and Tobago and Brazil, respectively [8][9][10][11]. These procedures were applied while the animals under anaesthesia. Such unconscious or semiconscious states were necessitated due to the very flighty nature of these specific fauna [8,10,11]. ...
... These procedures were applied while the animals under anaesthesia. Such unconscious or semiconscious states were necessitated due to the very flighty nature of these specific fauna [8,10,11]. Collection of ejaculates were accomplished by the sequential application of low voltages using an anal probe. The probe has electrodes which act as the conductors. ...
... The sequence was repeated with various modifications until the animal ejaculated. Such adjustments included incrementally increased voltages (IIV), increased application times of the applied voltages, increased time for the rest period, number of sequences in a set, or dosages of various anaesthetics [8,11]. In all instances the drugs were administered intramuscularly. ...
The meat of Neo-tropical fauna is savoured in parts of the Caribbean, Central and South America. Dasyprocta species is one animal hunted for its meat and this activity may eventually threaten their survival. However, efforts made to domesticate these wild animals lead to the development of farming systems. Reproduction has been a valuable tool in the process of domestication. Therefore, part of this effort included research directed at understanding the reproductive attributes of the male agouti. Electro-ejaculation was used to collect semen from Dasyprocta leporina and Dasyprocta azarae. This mini review compared three electro-ejaculation protocols developed for Dasyprocta species in Brazil and the Republic of Trinidad and Tobago. These procedures were applied after the animals were anaesthetized. Collected ejaculates that contained spermatozoa were expressed as percentages of the total number of ejaculated collected and used as a measure of the effectiveness for the respective three Protocols. The most effective was Protocol 3 (100%). However, this was achieved with the administering of 5 different anaesthetics which may cause some potential damage to the agouti. Conversely, 75% successes were obtained then Xylazine 20mg/ kg (Protocol 1, T4) and Ketamine 20mg/kg and Xylazine 40mg/kg (Protocol 2, T8) were administered, respectively. The ejaculate with the largest concentration of spermatozoa (431±180×10 6 /ml) were collected for Protocol 1, T4. Furthermore, no such specifics were listed for ejaculates collected from Protocol 3. In conclusion, the three Protocols should be reviewed to develop a procedure which utilizes resources efficiently and produces results that are quantitatively and qualitatively desirable.
... Anaesthesia was performed using ketamine, intramuscularly, five minutes before electro-ejaculation was performed. However, this protocol was improved by the inclusion of lower dosages of xylazine in combination with ketamine, since xylazine at a dosage of 40 mg/kg resulted in 75% of ejaculate samples containing spermatozoa [27]. To conduct the electro-ejaculation stimuli sequence, six volts were applied for a five second period (on period), followed by a five second rest period (off time). ...
... It was concluded that the maximum electro-ejaculation time should be six minutes, with off periods of three to four seconds. The utilized electro-ejaculation technique was able to yield an average spermatozoa concentration of 106.7 ± 31.1 × 10 6 spermatozoa/mL, while the highest spermatozoa concentration yielded by Mollineau et al. [27] was 431 ± 180 × 10 6 spermatozoa/mL. ...
... The agoutis were anaesthetized using ketamine (35 mg/kg) and xylazine (5 mg/kg) intramuscularly. It was concluded that ring electrodes with a serial stimuli protocol improved the efficiency of semen collection via electro-ejaculation as 57% of ejaculate samples contained spermatozoa, as compared with 41.33% and 40.8% [27] and 30% [26]. ...
This review, which is the first of two, focuses on the male reproductive anatomy and reproductive technologies used in Neo-tropical hystricomorphic rodents with the potential for domestication, which are the agouti (Dasyprocta leporina), the capybara (Hydrochoerus hydrochaeris) and the paca (Cuniculus paca). We consider over seventy references spanning from 1965 to 2020, with the majority of work being done in the past twenty years. Knowledge of the reproductive tract and reproductive technologies is critical to the conservation and preservation of these species. Although all three animals had similarities in their anatomy, such as no overt scrotums and testes located intra-abdominally in the inguinal region, some had unique features—for example, the agouti and the paca had penile spines, and two lateral penile cartilages. High spermatogenic efficiency was noted in the agouti and the paca, making them good candidates for increasing their reproductive performance in conservation programs. A review of the literature has shown that there is increasing work taking place on the reproductive technologies used in these animals; however, a lot of work is still lacking, as, to the author’s knowledge, standard protocols and artificial insemination procedures are yet to be established.
... This line of research also included semen collection by electroejaculation (EE) from Dasyprocta leporina and Dasyprocta azarae in the Republic of Trinidad and Tobago and Brazil, respectively [8][9][10][11]. These procedures were applied while the animals under anaesthesia. Such unconscious or semiconscious states were necessitated due to the very flighty nature of these specific fauna [8,10,11]. ...
... These procedures were applied while the animals under anaesthesia. Such unconscious or semiconscious states were necessitated due to the very flighty nature of these specific fauna [8,10,11]. Collection of ejaculates were accomplished by the sequential application of low voltages using an anal probe. The probe has electrodes which act as the conductors. ...
... The sequence was repeated with various modifications until the animal ejaculated. Such adjustments included incrementally increased voltages (IIV), increased application times of the applied voltages, increased time for the rest period, number of sequences in a set, or dosages of various anaesthetics [8,11]. In all instances the drugs were administered intramuscularly. ...
... At each increase, the on and off sequence was repeated. At this point, the entire sequence was repeated until the animal ejaculated or 10 min had elapsed (Mollineau et al., 2008(Mollineau et al., , 2010. The various stages of erection were photographed with a Ni-kon D300s camera (Nikon Inc., Melville, NY, USA) with Micro Nikkor 105 mm lens. ...
... During copulation, it is possible that the pressure from the vagina on the penis may be increased due to the spreading of the lateral penile cartilages and the formation of the penile flower, which may result in ejaculation (Fig. 1d). This information would assist in semen collection (Mollineau et al., 2010) for use in reproductive techniques for the agouti such as artificial insemination. ...
The reproductive system of the male agouti is not well documented. This study describes the specific anatomical features of the free part of the penis occurring during penile erection in the agouti. Electro-ejaculation was used to induce erection in three male agoutis that had previously produced offspring. Results proved that there were four stages in the erection process. Stage 1 involved protrusion of the penis from the preputial orifice. The lateral penile cartilages were then spread (stage 2). During stage 3, there was the blooming of the head of the glans penis (penile flower) and eversion of the intromittent sac. The protrusion of the keratinaceous styles and ejaculation occurred during stage 4. This information could assist in semen collection for use in reproductive techniques for the agouti such as artificial insemination.
... Thus, the authors obtained an efficiency of 30% of ejaculates containing spermatozoa. In a subsequent study using the same electroejaculation protocol, but starting at 2 V, an efficiency of 40% of ejaculates containing spermatozoa was obtained (Mollineau et al., 2010a). Additionally, Castelo et al. (2016) demonstrated the interaction between different types of electrical stimuli, as sine or quadratic waves, and electroejaculation using ring or strip electrode apparatus with better results than those reported by Mollineau et al. (2008Mollineau et al. ( , 2010. ...
... Through electroejaculation, Mollineau et al. (2010a) diluted the ejaculates of D. leporina in ultrahigh-temperature (UHT) milk, unpasteurized coconut water, or pasteurized coconut water under refrigeration at 5°C. After 24 h of storage, best results were achieved in the samples diluted in UHT milk, with sperm motility values of 59.5 ± 7.75%. ...
Dasyprocta spp. (agouti) include wild rodents with highlighted ecological and economic importance, and are considered experimental models for endangered hystricognath rodents. Of late, development of techniques to conserve their genetic material as well as the formation of biobanks is increasing. In this context, this review describes the main advances in the knowledge of the reproductive morphophysiological specificities of agouti as well as the development and improvement of assisted reproductive techniques aimed at conservation, multiplication, and exploitation of their reproductive potential under captivity.
... This method is, moreover, less invasive than a biopsy and, compared to autopsies, spares lives of animals (cf. [19][20][21][22]). ...
... Sperm concentration of anaesthetized chinchillas (204x10 6 /ml) [20] is comparable to the sperm concentration found here in anaesthetized Ansell's mole-rat (187x10 6 /ml). Mollineau et al. [21] used several different doses of ketamine and xylazine and two different induction times to find the best outcome of electroejaculation in agoutis (Dasyprocta leporina). The highest sperm concentration of 431x10 6 /ml was obtained under relatively high anaesthetic doses. ...
Ansell’s mole-rats (Fukomys anselli) are subterranean rodents living in families composed of about 20 members with a single breeding pair and their non-breeding offspring. Most of them remain with their parents for their lifetime and help to maintain and defend the natal burrow system, forage, and care for younger siblings. Since incest avoidance is based on individual recognition (and not on social suppression) we expect that non-breeders produce viable sperm spontaneously. We compared the sperm of breeding and non-breeding males, obtained by electroejaculation and found no significant differences in sperm parameters between both groups. Here, we used electroejaculation to obtain semen for the first time in a subterranean mammal. Spermiogram analysis revealed no significant differences in sperm parameters between breeders and non-breeders. We found significantly larger testes (measured on autopsies and on living animals per ultrasonography) of breeders compared to non-breeders (with body mass having a significant effect). There were no marked histological differences between breeding and non-breeding males, and the relative area occupied by Leydig cells and seminiferous tubules on histological sections, respectively, was not significantly different between both groups. The seminiferous epithelium and to a lesser degree the interstitial testicular tissue are characterized by lesions (vacuolar degenerations), however, this feature does not hinder fertilization even in advanced stages of life. The continuous production of viable sperm also in sexually abstinent non-breeders might be best understood in light of the mating and social system of Fukomys anselli, and the potential to found a new family following an unpredictable and rare encounter with an unfamiliar female (“provoked or induced dispersal”). Apparently, the non-breeders do not reproduce because they do not copulate but not because they would be physiologically infertile. The significantly increased testes volume of breeding males (compared to non-breeders) is in agreement with previously found higher testosterone levels of breeders.
... 5 To put into prospective the recent mini avalanche of reviewed articles on the anatomy and physiology of the male's agouti reproductive system, the majority of which came out of Brazil and some other South American countries, and to a lesser extend Trinidad and Tobago. 6,7 This paper focuses on the anatomy of the male reproductive system of three Dasyprocta spp. with the aim to facilitate the reproductive contribution of this initial body of knowledge in other reproductive work on the species. ...
This mini review examines the major articles published on the anatomy of the male reproductive system of three Dasyprocta species., namely Dasyprocta aguti, Dasyprocta leporine and Dasyprocta prymnolopha. The paper reviews major investigations on the topic and highlights additional research (collection and processing of agouti semen) which used this foundational knowledge set as its catalyst. Future scientific works are recommended based on the existing literature.
... Merece destaque o gênero Dasyprocta, onde pesquisas relevantes na área de produção animal (Lopes et al. 2004, McWilliams, 2009, Anderson et al. 2018, biotecnologias da reprodução (Rodrigues et al. 2006, Mollineau et al. 2010, Fortes et al. 2013, Martinez et al. 2013, anatomia descritiva (Odekunle et al. 2013, Silva et al. 2014, Oliveira et al. 2016, Costa et al. 2017) e fisiologia cardíaca (Diniz et al. 2013a, Diniz et al. 2013b, Moura et al. 2015, Alves et al. 2017, Pessoa et al. 2018) são realizadas. Possuem predominantemente hábitos diurnos (Cid, Oliveira-Santos & Mourão, 2015) desempenham papel predatório-dispersor na cadeia alimentar (Levin, 2007) ao incluir em sua dieta o consumo de sementes, favorecendo sua dispersão no entorno onde habitam (Taylor, Ickes & DeWalt, 2014). ...
Para contenção química de cutias (Dasyprocta spp.) comumente utiliza-se dissociativos, dos quais, a cetamina combinada a opioides, benzodiazepínicos e agonistas α-2 adrenérgicos têm sido empregados destacando-se os tempos anestésicos, parâmetros fisiológicos e eletrocardiograma, entretanto, a busca por protocolos mais seguros que provoquem efeitos depressores mais brandos ou inexistentes e ainda proporcionem melhor recuperação é desejável. O experimento em questão comparou os efeitos fisiológicos, qualidade da anestesia e recuperação anestésica de dois protocolos: CeBuDex - cetamina (20 mg/kg) + butorfanol (0,02 mg/kg) + dexmedetomidina (0,05mg/kg) e CeBuXi - cetamina (20 mg/kg) + butorfanol (0,02 mg/kg) + xilazina (1,5 mg/kg), ambos por via intramuscular. Os parâmetros vitais, períodos anestésicos e eletrocardiograma computadorizado foram analisados e comparados entre os grupos. Os dois protocolos apresentaram período de latência rápido (PLATÊNCIA < 5 minutos). Período hábil médio para CeBuDex foi de 83,9 ± 32,9 min. e para CeBuXi foi de 57,1 ± 10,78 min. Períodos de recuperação total médios foram de 48,6 ± 35,3 min. para CeBuDex e 44,1 ± 13 min. para CeBuXi. Quanto à qualidade de recuperação, em CeBuDex os animais apresentaram retorno mais tranquilo, enquanto em CeBuXi mais agitado. Para a frequência cardíaca houve diminuição progressiva e menores valores em CeBuXi. Quanto aos valores de SpO2 CeBuDex, apresentou menores valores que CeBuXi, porém sem intercorrências como membranas mucosas hipocoradas e/ou cianóticas, tendo os níveis de saturação atingido valores acima de 90% a partir de 30 minutos após aplicação dos fármacos, em ambos os protocolos. Deve-se ter em consideração a ocorrência de possíveis complicações, como hipóxia total e necessidade de suplementação de oxigênio, ambos não presentes ao longo do experimento.
... Several articles have been published on the male anatomy of the agouti. The micro-and macro-anatomy of the male reproductive tract [3,4], the electro-ejaculates of the male agouti has been analyzed and these ejaculates have been extended and stored [4][5][6][7][8]. Finally, the stages of erection in the male agouti have been investigated [9]. ...
Dystocia is a complication that occurs at parturition either due to foetal or maternal factors. This condition has been well studies in domesticated species. However, there is very little information on dystocia in the agouti (Dasyprocta leporina). The agouti is utilized for its meat in South America and the Caribbean. More recently, farming of these animals intensively is being practiced in the Neo-tropics. This case report attempted to provide some insight into dystocia in the agouti which has been rarely reported in animals in captivity. A female agouti weighing approximately 3 kg (kg), which was in the last stage of pregnancy, was found dead in its cage. The vulva of the animal had the hind-limbs of the offspring protruding. Upon necropsy the animal had little fat reserves and had two foetuses in the right horn of the uterus. The feet of on offspring were dislocated and exposed at the level of the vulva. Each foetus weighed approximately 200 g. The foetuses were well formed with fur, teeth and eyes. The placenta was attached to each of the foetuses. The pathological findings suggested that dystocia resulted in secondary uterine inertia, which was the cause of death of the adult female agouti. To prevent the recurrence of this situation the gestation should be staged (timed) using ultrasonography. Animals which are in their third stage of gestation should be monitored using cameras or with personnel at the facility to assist agoutis which are having difficulties at parturition.
... Small hindgut fermenters like the agouti require more energy for metabolic functions and have a large caecum when compared to their body size (Sakaguishi 2003). Significant work has been done on the male agouti's reproductive system (Mollineau et al 2006(Mollineau et al ,2008(Mollineau et al (a),2008(Mollineau et al (b),2009(Mollineau et al ,2010(Mollineau et al ,2011(Mollineau et al (a),2011(Mollineau et al (b),2012(Mollineau et al , 2013. The gross and microscopic anatomy of the female agouti reproductive system has also been studied (Guimaraes et al 2009(Guimaraes et al ,2011Singh et at 2014). ...
This study was conducted to determine the prevalence of gastrointestinal parasites in the agouti, the species of endoparasites present in the gastrointestinal tract and the body condition of the affected animals. Endoparsites in rabbits were also investigated to determine if there were common parasites of the rabbit and the agouti. This study was done in two phases. Phase 1 entailed the collection and analyses of faecal samples, using the faecal floatation technique from the agoutis which were intensively reared in cages and on a cement floor at four locations in Trinidad. The average live body weight of the agoutis ranged from 2.69 kg to 2.56 kg. Helminth eggs found in the agoutis in Phase 1 (n=65) of the study included Strongyloides spp. 36.9%, Trichuris spp. 4.62% and Paraspidodera uncinata 15.4%. In Phase 2 of the study eight agoutis and eight rabbits were slaughtered and contents of different anatomical regions of the gastrointestinal tract were examined using faecal floatation techniques for parasites of both mammals. The cage reared agoutis were captive reared at the University of the West Indies University Field Station (UFS). The rabbits were commercially cage reared at the Sugarcane Feed Centre (SFC). Coccidia oocysts were observed in the contents of the stomach, caecum, colon and rectum of the rabbit. In the agoutiStrongyloides spp. eggs and were found in the caecal contents. Trichuris spp. eggs were found in the caecum and rectum and Paraspidodera uncinata eggs were found in the rectum only. The agoutis sampled had an average body condition score of three.
This study investigated the gross and microscopic anatomy of the reproductive tract of five cage reared female agouti (Dasyprocta leporina). The ovaries were paired yellow ovoid bodies with a mean (± SD) length of 10 mm (± 2.1), held near the caudal pole of the kidneys. The ovarian cortex consisted of cellular connective tissue in which ovarian follicles were embedded. Highly vascularized tissue was noted in the ovarian medulla. The fallopian tubes increased in width caudally from the ovary to the uterus. Paired uterine horns converged to form the Y-shaped uterine body and the characteristic duplex uterus was separated by a septum. The cervix was found at the pelvic inlet and protruded into the proximal vaginal lumen as the fornix. The vagina had a mean (± SD) length of 7 cm (± 11.4), representing the longest portion of the reproductive tract. Differences in vaginal epithelium were evident, indicating that vaginal colpocytology may be used to evaluate the reproductive stage of the female agouti in captivity. The distance between the urethral aperture and the anus may be used to determine the sex of cage reared agouti, especially when the perineum seals the vaginal orifice.
The major objective of this study was to evaluate the trainability of the adult male agouti using a service cage (SC) for mating. The study included two phases. Phase 1 involved designing and constructing service cages (SC). Phase 2 focused on acclimatizing the agouti to the SC and evaluating the animals' responses. Initially agoutis were placed in the SC for 15 minutes. Thereafter, the time spent in the SC was incrementally increased by 15 minutes every two days over sixteen days. Behavioural traits evaluated were: (1) response to capture; (2) response on entering the SC; (3) activity in the SC; (4) response to food, and (5) response on leaving the SC. Scores ranging from 1 (least desirable responses) to 4 (most desirable responses) were allocated to each behavioural trait based on the animals' response. Prototype 3 of the three service cages built to house the agoutis proved the most suitable design. Total mean scores improved from 6.5 ± 0.5 (Day 1) to 18.5 ± 1.5 (Day 16). The relationship between time and scores was significant (P<0.05). The largest rates of change occurred on Days 5 and 6 (28.57%). It was concluded that the adult, male agouti can be trained to use a SC.
This study investigated the gross and microscopic anatomy of the reproductive tract of five cage reared female agouti (Dasyprocta leporina). The ovaries were paired yellow ovoid bodies with a mean (± SD) length of 10 mm (± 2.1), held near the caudal pole of the kidneys. The ovarian cortex consisted of cellular connective tissue in which ovarian follicles were embedded. Highly vascularized tissue was noted in the ovarian medulla. The fallopian tubes increased in width caudally from the ovary to the uterus. Paired uterine horns converged to form the Y-shaped uterine body and the characteristic duplex uterus was separated by a septum. The cervix was found at the pelvic inlet and protruded into the proximal vaginal lumen as the fornix. The vagina had a mean (± SD) length of 7 cm (± 11.4), representing the longest portion of the reproductive tract. Differences in vaginal epithelium were evident, indicating that vaginal colpocytology may be used to evaluate the reproductive stage of the female agouti in captivity. The distance between the urethral aperture and the anus may be used to determine the sex of cage reared agouti, especially when the perineum seals the vaginal orifice.
Keywords: Anatomy; Dasyprocta; Female Agouti; Histology; Reproduction
The reproductive system of the male agouti is not well documented. This study describes the specific anatomical features of the free part of the penis occurring during penile erection in the agouti. Electro-ejaculation was used to induce erection in three male agoutis that had previously produced offspring. Results proved that there were four stages in the erection process. Stage 1 involved protrusion of the penis from the preputial orifice. The lateral penile cartilages were then spread (stage 2). During stage 3, there was the blooming of the head of the glans penis (penile flower) and eversion of the intromittent sac. The protrusion of the keratinaceous styles and ejaculation occurred during stage 4. This information could assist in semen collection for use in reproductive techniques for the agouti such as artificial insemination.
This study focused on the effectiveness of electro-ejaculation of the agouti (Dasyprocta leporina) and analysis of the collected semen. Sexually mature male agouti were anesthetized with ketamine and electro-ejaculated. The means of ejaculation time was 5.48+/-0.31min, ejaculation voltage was 9.33+/-0.69V, ejaculation voltage range was 6-12V, amps was 0.5-1.5amps, ejaculation volume was 0.47+/-0.12ml and pH was 8.3+/-0.09. Mean spermatozoa concentration, motility and percentage abnormalities were (106.7+/-31.1)x10(6)spermatozoa/ml, 50.44+/-4.44%, and 35.14+/-2.76%, respectively. Thirty percent of the semen samples collected contained spermatozoa. The most significant result from these experiments was the inverse relationship between ejaculation time and ejaculate volume, which suggests that the maximum ejaculation time for electro-ejaculation of the agouti should not proceed beyond 6min. Secondly, the results indicate that the time of the off periods should be shortened to 3-4s.
Analysis of 40 semen samples collected by electroejaculation from 18 cheetahs revealed no major differences in seminal traits among Transvaal, South West (Namibia) or hybrid (Transvaal X South West) males. However, mean spermatozoal concentration (14.5 X 10(6) spermatozoa/ml of ejaculate) and percent motility (54.0%) were less in cheetahs than in domestic cats (147.0 X 10(6) spermatozoa/ml of ejaculate, 77.0% motility) subjected to the same electroejaculation regimen. On the average, cheetah ejaculates contained 71.0% morphologically abnormal spermatozoa compared to 29.1% aberrant spermatozoal forms in the domestic cat. These results indicate that seminal characteristics in the cheetah are markedly inferior compared to the domestic cat, particularly with respect to the incidence of pleiomorphic spermatozoa. Because a recent parallel study demonstrates that the cheetah lacks genetic variation, it appears likely that spermatozoal abnormalities are a genetic consequence of genomic homozygosity characteristic of this endangered species.
Wild red howler monkeys (Alouatta seniculus) were translocated during the flooding of the forest at a hydroelectric dam site in French Guiana. For a variety of minor clinical procedures, 96 monkeys were anesthetized with various intramuscular injections of combinations of medetomidine and ketamine. The howler population was composed of healthy animals (42 males and 54 females) of various ages. Medetomidine (150 μg/kg) associated with ketamine (4 mg/kg) gave the best results and was used on 63 animals. The injection rapidly resulted in complete immobilization with good to excellent myorelaxation. The induction stage was quiet, with absence of both corneal and pedal withdrawal reflexes in 57 animals after 2.9 ± 1.4 min. Six animals required an additional injection. Rectal temperature and respiratory and heart rates decreased during anesthesia, whereas relative oxyhemoglobin saturation increased. One death occurred during anesthesia. One abortion and one death also occurred the day following anesthesia but were more probably a result of capture stress. Atipamezole given i.m. at a dose of five times the medetomidine dose 38.4 ± 8.0 min after the anesthetic injection led to standing recovery in 7.1 ± 4.5 min. Spontaneous recovery occurred in 17 animals before the atipamezole injection after an average of 30.6 ± 9.6 min. Total recovery time was shorter in young animals. Medetomidine/ketamine induced good myorelaxation and provided considerably shortened immobilization duration, which are two notable advantages for field studies. We recommend this association for short procedures including minor surgery in red howler monkeys. Am. J. Primatol. 45:399–410, 1998. © 1998 Wiley-Liss, Inc.
The technique of rectal probe electroejaculation has been developed to permit collection of semen using equipment proven safe, simple, and effective on the 30 primate species so far tested. This paper provides information on the construction and operation of this equipment, together with electrical parameters applicable to primate species. Seminal emission or ejaculation occurs in all species when alternating current is delivered at 0.25 mA/mm2 electrode area. The most effective frequency is 20 Hz, and the most acceptable anesthetic is ketamine hydrochloride.
A procedure for electroejaculation of domestic cats was developed. The method involved anesthetization of adult male cats with ketamine HC1 (33 mg/kg) or CI 744 (5.5 mg/kg). Optimal results were obtained with a 120-V ac electric stimulator capable of a continuous range of 0 to 60 V and 0 to 1 A. Using a 1- by 12-cm rectal probe constructed of teflon and stainless steel electrodes, ejaculation was obtained with an electrical stimulus over a range of 2 to 8 V and 5 to 220 mA. Voltage and amperage were increased at specific intervals in order to compensate for refractory ejaculatory response due to continued nerve and muscle stimulation. The procedure provided a means of obtaining ejaculates from domestic cats for purposes of semen evaluation and artificial insemination.
Six baboons (Papio ursinus) males were immobilised on five occasions at intervals of two weeks using a combination of ketamine hydrochloride and xylazine. The animals were subsequently successfully electro-ejaculated. No semen was obtained from animals when azaperone was used instead of xylazine, despite the use of a successful standardised method of electrical stimulation.
Analysis of 40 semen samples collected by electroejaculation from 18 cheetahs revealed no major differences in seminal traits among Transvaal, South West (Namibia) or hybrid (Transvaal X South West) males. However, mean spermatozoal concentration (14.5 X 10(6) spermatozoa/ml of ejaculate) and percent motility (54.0%) were less in cheetahs than in domestic cats (147.0 X 10(6) spermatozoa/ml of ejaculate, 77.0% motility) subjected to the same electroejaculation regimen. On the average, cheetah ejaculates contained 71.0% morphologically abnormal spermatozoa compared to 29.1% aberrant spermatozoal forms in the domestic cat. These results indicate that seminal characteristics in the cheetah are markedly inferior compared to the domestic cat, particularly with respect to the incidence of pleiomorphic spermatozoa. Because a recent parallel study demonstrates that the cheetah lacks genetic variation, it appears likely that spermatozoal abnormalities are a genetic consequence of genomic homozygosity characteristic of this endangered species.
The effect of epidural administered xylazine was investigated in 10 mature Holstein cows (mean age: 5.4 +/- 1.2 years, mean BW: 572 +/- 23 kg): 5 cows were treated with xylazine in a low dose of 0.05 mg/kg body weight, 3 cows in a medium dose (0.07 mg/kg BW) and 2 cows in a high dose (0.1 mg/kg BW). Xylazine dosages were diluted in sterile saline to a final volume of 5 ml. As a control, lidocaine (5 ml of a 2% solution) was given to 5 cows epidurally. Duration of regional anaesthesia after low dose of xylazine (0.05 mg/kg BW) was significant longer (mean: 2.2 hours) compared to lidocaine treated cows (mean: 1.1 hour). Regional extension of anaesthesia was comparable after dosing with xylazine and lidocaine (tail, after, vulva and perineum). All cows remained standing, but in xylazine treated cows systemic effects, e.g. mild sedation, decreased heart- and respiratory rates, decreased rumen motility and mild bloat were observed. With increased dosages of xylazine a prolongation of epidural anaesthesia up to 3 hours was achieved, but regional extension of this effect remained nearly unchanged. With increased xylazine dosages, cows showed marked sedation and ataxia and sternal recumbency were induced.
Nine-banded (n = 47) and great (n = 31) long-nosed armadillos (Dasypus novemcinctus and Dasypus kappleri) were immobilized for clinical examination and collection of biological samples as part of a wildlife rescue during the filling of a hydroelectric dam (Petit Saut, French Guiana) from May 1994 to April 1995. Three intramuscular (i.m.) anesthetic combinations were evaluated: (1) tiletamine/zolazepam (T/Z) at a dose of 8.5 mg/kg in 12 nine-banded long-nosed armadillos (NBA) and 10 great long-nosed armadillos (GLA), (2) ketamine at 40 mg/kg combined with xylazine at 1.0 mg/kg (K/X) in 18 NBA and nine GLA, and (3) ketamine at 7.5 mg/kg combined with medetomidine at 75 microng/kg (K/M) in 17 NBA and 12 GLA, antagonized by 375 microg/kg atipamezole. Induction was smooth, ranged from mean +/- SD = 2.8+/-0.6 to 4.3+/-1.8 min, and did not differ significantly between protocols, species, or sex. In NBA, immobilization time ranged from 43.8+/-27.8 to 66.5+/-40.0 min and did not differ between protocols or sex. Muscle relaxation was judged to be better with K/X and K/M versus T/Z. In GLA, the response to the anesthetic protocols was more variable and immobilization time ranged from 30.4+/-6.2 to 98.4+/-33.7 min. The main difference was observed in GLA females receiving the T/Z combination, in which immobilization time was significantly longer versus males, but also versus GLA K/M group, and versus NBA T/Z group. Effects on body temperature, heart rate and respiratory rate were limited. Thirty six to 50% of the individuals showed hypoxemia (SpO2 < 85%) throughout anesthesia and values <80% also were recorded but the hypoxemia was not associated with clinical signs. With T/Z and K/X, recovery was irregular and prolonged up to 2 to 3 hr in some individuals. In K/M groups, first standing was observed 1.0 to 16.4 min after i.m. atipamezole injection without adverse effects. Finally, the three anesthetic combinations used in this study were effective and safe agents for 30 to 40 min immobilizations including minor surgery procedures. The ability to antagonize the medetomidine-induced sedation with atipamezole significantly reduces the recovery time, making the K/M combination preferable, especially in field conditions.
Cardiopulmonary effects and the utility of a butorphanol/xylazine/ketamine combination were evaluated during twenty immobilizations of sixteen Baird's tapirs (Tapirus bairdii) between March 1996 and January of 1998 in Corcovado National Park (Costa Rica). The animals were attracted to a bait site and darted from tree platforms. The tapirs were estimated to weigh between 200 to 300 kg. Actual weights of three tapirs taken at later dates fell within the estimated range. A butorphanol, 48+/-1.84 (x +/- SE) mg/animal IM, and xylazine, 101+/-2.72 mg/animal IM, combination was used to immobilize the animals. In some instances, ketamine was used either IM or IV at 187+/-40.86 mg/animal to prolong the immobilization period in addition to the butorphanol/xylazine combination. Naltrexone was used IM to reverse butorphanol at 257+/-16.19 mg/animal. Either yohimbine, 34+/-0.61 or tolazoline at 12+/-10.27 mg/animal, was used to reverse xylazine. The mean time from dart impact to first visible effect was 4.63+/-0.50 min (x +/- SE). Mean time to sternal recumbency was 12.21+/-1.08 min. Mean time the tapirs were immobilized was 45.63+/-3.6 min. Mean time to return to sternal recumbency and standing in animals that received yohimbine and naltrexone was 3.16+/-1.06 and 5.33+/-1.45 min, respectively. Mean time to return to sternal recumbency and standing in animals that received tolazoline and naltrexone was 1.57+/-0.39 and 3.14+/-0.51 min, respectively. Cardiopulmonary parameters including heart rate, respiratory rate, body temperature, electrocardiogram, percent oxygen satoration, and indirect blood pressure were recorded. Arterial blood gas analysis was performed on four animals. A mild degree of hypoxemia was evidenced by low arterial oxygen saturations. Five of 14 (36%) animals measured had oxygen saturations below 90%. Bradycardia (heart rates <45 BPM) was an expected finding in 11 (55%) immobilizations. Induction, recovery and muscle relaxation of each immobilization was graded. Premature arousal, which occurred in six (30%) animals, was the only problem associated with the immobilizations. Butorphanol/xylazine is a recommended protocol for immobilization of calm, free-ranging tapirs lasting less than 30 min. Supplemental intravenous administration of ketamine is recommended for longer procedures. Nasal insufflation of oxygen is recommended.
Thirteen sexually mature captive male lesser Malay chevrotains (Tragulus javanicus) were each anesthetized twice with tiletamine-zolazepam for electroejaculation. Viable spermatozoa were collected from all animals. The semen was creamy, milky, pale yellowish, or watery. The mean values for ejaculate volume, sperm concentration, and percentages of sperm motility, normality and viability were 23.7 +/- 2.5 microl, 366.9 +/- 127.8 x 10(6) spermatozoa/ml, 40.0% +/- 3.1%, 71.4% +/- 1.6%, and 59.6% +/- 2.1%, respectively. Semen pH was 7-8. No adverse effects of electroejaculation were noted. These are the first reported values for semen of lesser Malay chevrotain. Electroejaculation should be usable for routine semen collection in this species.