Publications by authors named "Cheryl Asa"

Melengestrol acetate (MGA) implants are a progestin-based reversible contraceptive used to manage fertility in animals. MGA implants are recommended for replacement every 2 years; however, reproduction may be suppressed longer if implants are not removed. In this study, we investigated whether the probability of reproducing (pR) differed among nonimplanted females, females with MGA implants removed, and females whose implants were not removed.

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Genome resource banks (GRBs) have the potential to preserve the genetic diversity of a species over time, yet they are rarely utilized as effective components of conservation breeding programs. Advances have been made in reproductive biology, collection and storage techniques, and use of stored gametes for achieving successful reproduction, but there are few guidelines for integrating GRBs into established breeding programs. Here we present basic guidelines, focusing on strategies for the collection, maintenance, and use of semen GRBs for protecting genetic diversity.

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Managing social groups in zoos requires controlling reproduction in individuals that do not have a current breeding recommendation, while simultaneously maintaining social harmony and animal well-being. Contraceptives, such as gonadotropin releasing-hormone (GnRH) agonists, that suppress testosterone production, offer a potential solution. They achieve infertility by interrupting spermatogenesis and may ameliorate androgen-induced aggression.

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The Association of Zoos and Aquariums Reproductive Management Center (RMC) in the US and the European Association of Zoos and Aquaria Reproductive Management Group (RMG) in Europe monitor efficacy of contraceptive products in participating institutions and use those results to inform contraceptive recommendations. This study used the joint RMC-RMG Contraception Database to analyze efficacy of deslorelin implants (Suprelorin), a contraceptive used in a wide range of mammalian taxa. More recently its use has increased in birds and in some reptiles and fish.

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Melengestrol acetate (MGA) implants are progestin-based reversible contraceptives used to manage fertility in zoo populations. Although it is recommended that MGA implants should be replaced every 2 years, the duration of efficacy has not been systematically evaluated in most species. Anecdotal reports for Old World monkeys indicate that reproduction may be suppressed longer if the implant is not removed.

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Wildlife conservation requires varying degrees of management of endangered species as well as management of their potential predators and competitors. Conservation also depends on ameliorating human-wildlife conflict, especially where there is a threat to the safety of people and of their pets and livestock. In addition, sustainability of wildlife populations can be affected by feral domestic animals or invasive species, that require removal or control.

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Many animal populations managed by the Association of Zoos and Aquariums' (AZA) Species Survival Plans® (SSPs) have low rates of reproductive success. It is critical that individuals recommended to breed are successful to achieve genetic and demographic goals set by the SSP. Identifying factors that impact reproductive success can inform managers on best practices and improve demographic predictions.

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Many breeding programs managed by the Association of Zoos and Aquariums' (AZA) Species Survival Plans® (SSPs) are not meeting goals for population size and genetic diversity due to failure of recommended pairs to breed successfully. According to AZA Population Management Center analyses, as many as 80% of recommended breeding pairs fail to produce young before the next breeding and transfer plan is issued. Determining reasons for failure and ensuring that a specific pairing produces offspring can be challenging.

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Understanding the factors used by female cheetahs (Acinonyx jubatus) to make mate choice decisions could benefit zoo breeding programs, which currently assign mates based primarily on genetic distance. Because transporting animals between institutions is costly and can be stressful, females are often limited in the number of males available for mating. One solution would be to determine if an easily transported substance could be used to gauge interest by a female to a potential mate.

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Contraception in Dogs and Cats.

Vet Clin North Am Small Anim Pract

July 2018

Although surgical sterilization is the most common approach to reproductive management of dogs and cats in North America and many other places, there is growing interest in nonsurgical and reversible methods. This review summarizes the methods currently available for use as reversible contraception in dogs and cats, along with cautions about reported side effects. The products covered include synthetic steroid hormones, peptide hormone agonists, vaccines, and a barrier method.

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Although reproduction in the domestic horse has been well described, less is known about reproduction in wild equids. This study describes endocrine patterns associated with estrous cycles and pregnancy for Somali wild asses (Equus africanus somaliensis), an endangered African equid. Fecal samples were collected three times per week for more than 2 years from five female Somali wild asses at the Saint Louis Zoo; progestagen and estrogen metabolites were quantified using commercially available immunoassays.

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Following the production of western gray wolf (Canis lupus) x western coyote (Canis latrans) hybrids via artificial insemination (AI), the present article documents that the hybrids survived in captivity for at least 4 years and successfully bred with each other. It further reports that backcrossing one of the hybrids to a male gray wolf by AI also resulted in the birth of live pups that have survived for at least 10 months. All male hybrids (F1 and F2) produced sperm by about 10 months of age, and sperm quality of the F1 males fell within the fertile range for domestic dogs, but sperm motility and morphology, in particular, were low in F2 males at 10 months but improved in samples taken at 22 months of age.

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Contraception is an essential tool in reproductive management of captive species. The Association of Zoos and Aquariums (AZA) Reproductive Management Center (RMC) gathers data on contraception use and provides recommendations. Although apes have been given oral contraceptive pills (OCPs) for at least 30 years, there have been no published reports with basic information on why the pill is administered, formulations and brands used, and effects on physiology and behavior.

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The unsustainability of many animal programs managed by zoos and aquariums has brought renewed attention to unresolved questions about various management strategies. Solving the "sustainability crisis" for many species will require housing more adults and producing more offspring than there are existing spaces in accredited zoos and aquariums. Careful reproductive management is central to addressing this challenge, but opinions differ about which management strategies are best for an individual, for a species, for an institution, or for a country or region.

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Effective and humane management strategies for coyotes (Canis latrans) remain elusive. We hypothesised that exposure to a high dose of a gonadotrophin-releasing hormone (GnRH) agonist would cause prolonged suppression of the reproductive axis. Two groups of male coyotes were administered 47mg deslorelin in the form of either five 9.

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Fruit doves (Ptilinopus) constitute a genus of small to medium-sized, brightly colored arboreal birds, whose diets consist entirely of fruit. Little is known about the behavior of fruit doves because most species inhabit dense forests and are difficult to observe in the wild. This study describes the parental behavior of Jambu fruit dove pairs (Ptilinopus jambu) in a captive breeding program at the Saint Louis Zoo.

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Great hornbills (Buceros bicornis) are a long-lived, monogamous species that forms strong pair-bonds, and mate compatibility is thought to be important for successful reproduction. Within AZA, great hornbills are listed as a red SSP. The population consists of a limited number of individuals that do not breed reliably, and improving reproduction is a top priority for the Coraciiformes TAG.

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Using artificial insemination we attempted to produce hybrids between captive, male, western, gray wolves (Canis lupus) and female, western coyotes (Canis latrans) to determine whether their gametes would be compatible and the coyotes could produce and nurture offspring. The results contribute new information to an ongoing controversy over whether the eastern wolf (Canis lycaon) is a valid unique species that could be subject to the U. S.

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Coyotes (Canis latrans) are predators of livestock. Current management programs, primarily lethal control, are ineffective for long-term management of predation. Controlling reproduction of coyotes may reduce depredations if territory fidelity is maintained by breeding pairs.

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Zoos and other ex situ wildlife institutions can play an important role in species conservation by maintaining populations for education and research, as sources for potential re-introduction or reinforcement, and as ambassadors for financial support of in situ conservation. However, many regional zoo associations are realizing that current captive populations are unsustainable, with many programs failing to meet demographic and genetic goals to ensure long-term viability. Constraints on population size due to limited space often mandate delayed and/or less frequent breeding, but for females of many species this can have profound effects on fertility.

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The ability to safely and effectively manage reproduction is central to the success of AZA captive-breeding programs. Although the AZA Wildlife Contraception Center routinely monitors contraceptive safety, there have been no studies that compare the effects of contraceptive use to separation of males from females, the other option for preventing reproduction. We used retrospective medical records and pathology reports submitted by AZA and related facilities for the seven AZA-managed canid species to assess rates of uterine pathology relative to female reproductive life histories.

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We evaluated two approaches to improving in vitro wolf sperm survival. Both approaches aimed to reduce the exposure of sperm to prostatic fluid resulting from electroejaculation: (1) use of extender formulations recently developed for the domestic dog (the most closely related domestic species); and (2) dilution of ejaculate shortly after semen collection. Three commercial extenders were compared with the TRIS-based extender we had previously used.

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Genetic management of Mexican gray wolves includes semen banking, but due to the small number of animals in the population and handling restrictions, improvements in semen collection and cryopreservation rely on results from studies of domestic dogs. Semen collection from wolves requires anesthesia and electroejaculation, which introduce potentially important variables into species comparisons, as dog semen is typically collected manually from conscious animals. To investigate possible effects of collection method on semen quality, we compared semen collection by the traditional manual method and by electroejaculation (EE) in a group of dogs (n = 5) to collection by EE only in wolves (n = 7).

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We observed a group of three young female Somali wild asses to develop an ethogram of social behavior in the first phase of a longer term study of social, sexual, and maternal/infant behavior. The most unexpected finding was the frequency and extent of aggressive interactions, which included Charge, Drive, Neck Wrestle, Head Butt, and Body Slam, behaviors previously reported only for males of other equid species. The overall frequency of aggressive behavior was higher than that of affiliative behavior (84±16.

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