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United States Department of Agriculture

Agricultural Research Service

Title: Cinereous Vulture Semen Collection: Evaluation of Wild-Caught and Founder Males

Authors
item Long, Julie
item Willis, M - DENVER ZOOLOGICAL GARDENS

Submitted to: Journal of Zoo Biology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 25, 2005
Publication Date: N/A

Interpretive Summary: Wild-caught cinereous vultures were imported into North American zoos from 1958 to 1974; however, the actual age of these birds is unknown and it is not certain how long the founder population will continue to survive and reproduce in captivity. As a first step in developing assisted reproductive technology for the captive population, an effective semen collection method was devised for the cinereous vulture that permitted recovery of semen samples with minimal restraint.

Technical Abstract: Wild-caught cinereous vultures were imported into North American zoos from 1958 to 1974; however, the actual age of these birds is unknown and it is not certain how long the founder population will continue to survive and reproduce in captivity. As a first step in developing assisted reproductive technology for the captive population, an effective semen collection method was devised for the cinereous vulture that permitted recovery of semen samples with minimal restraint. During five consecutive breeding seasons, this method was used to collect semen from a total of 7 wild-caught and/or founder males and evaluate seminal traits. Semen volumes were variable, ranging from 5 to 60 µl; whereas the average pH (6.3 +/- 0.7) and osmolality (379.7 +/- 44.3 mosm/kg) of semen samples were consistent (p<0.05). Sperm concentrations of semen collected from female-paired males ranged from 2x105 to 17x106 sperm/ml, and 85.2% of samples collected prior to egg lay contained sperm. In contrast, only azoospermic samples were obtained from these males when semen collections were conducted after egg lay. Most of the semen samples (61.3%) contained non-motile sperm; the percentage of motile sperm in the remaining samples was highly variable and ranged from 10 to 85%. Several avian semen extenders were evaluated for the ability to maintain sperm motility in vitro; none of the extenders supported sperm motility beyond 90 min after collection. Interestingly, 2 males that had been previously paired with females continued to produce motile sperm for 1-2 breeding seasons after the death of the females, suggesting that older, solitary males could still contribute to the population through assisted reproduction.

Last Modified: 8/22/2014
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