Giant panda (Ailuropoda melanoleuca) sperm morphometry and function after repeated freezing and thawing

This work examines the effects of subsequent cycles of freezing-thawing on giant panda (Ailuropoda melanoleuca) sperm morphometry and function, and assesses whether density-gradient centrifugation (DGC) can increase the number of freezing-thawing cycles this sperm can withstand. A sperm sample was collected by electroejaculation from a mature giant panda and subjected to five freezing-thawing cycles. Although repeated freezing-thawing negatively affected (P < 0.05) sperm motility and membrane integrity, in both nonselected and DCG-selected sperm samples, >60% of the sperm cells in both treatments showed acrosome integrity even after the fifth freezing cycle. In fresh semen, the sperm head length was 4.7 μm, the head width 3.6 μm, area 14.3 μm(2) and perimeter length 14.1 μm. The present results suggest that giant panda sperm trends to be resistant to repeated freezing-thawing, even without DGC selection.

Morphological and molecular identification of Tetratrichomonas flagellates from the giant anteater (Myrmecophaga tridactyla)

A tetratrichomonad flagellate found in the diarrhoeic faeces of a 5 years-old male giant anteater (Myrmecophaga tridactyla) was characterised by morphological and genetic analysis. This protozoan presents four anterior flagella of unequal length and a recurrent flagellum attached to the undulating membrane without a free end portion, and a broad axostyle projection. Numerous vacuoles of different sizes containing bacteria and digestion products were found. The complete sequence of the DNA coding for the 16S rRNA-ITS1-5.8S rRNA-ITS2 region was also obtained in order to compare this isolate with other tetratrichomonad species. The sequence obtained was identical to others previously obtained by other researchers from bovines and turtles (Geochelone sp.). It is not easily explainable how the same organism could be found in such different hosts and locations; however these results indicate that some tetratrichomonad species could have a wide host range and could survive in a wide range of environmental conditions.

POST-THAW VIABILITY OF EUROPEAN BISON (BISON BONASUS) SEMEN FROZEN WITH EXTENDERS CONTAINING EGG YOLK OR LIPIDS OF PLANT ORIGIN AND EXAMINED WITH A HETEROLOGOUS IN VITRO FERTILIZATION ASSAY

Basic characteristics of European bison (Bison bonasus) semen were described and the efficacies of two extenders-Triladyl, containing egg yolk, and a synthetic extender, containing soybean lipids-were tested for semen cryopreservation. Seven ejaculates were collected by electroejaculation from a 10-yr-old, European bison bull. Each ejaculate was diluted at 37 degrees C to a final concentration of 200 x 10(6) sperm/ml with Triladyl or the synthetic extender. Extended semen samples were frozen according to a standard bull semen freezing protocol. After 2 wk of storage, one straw from each extender and ejaculate was thawed, and postthaw quality was evaluated by individual sperm motility and movement rate, numbers of sperm morphologic abnormalities and intact acrosomes, functional integrity of the sperm membranes determined by hypoosmotic swelling test (HOST), viability (live-dead, eosin-nigrosin stain), and a heterologous in vitro sperm penetration assay (SPA). A total of 600 in vitro-matured bovine oocytes were inseminated with 1 X 10(6) spermatozoa of Holstein semen frozen-thawed in Triladyl (control) or of European bison semen frozen in Triladyl or the synthetic extender. Nuclear status of the oocytes was determined after 18 h of sperm-oocyte coincubation. Extender had no effect on any evaluated parameters of semen after dilution and cooling (4 hr at 5 degrees C) or in postthaw individual motility, quality of movement, and sperm morphology. However, significantly (P < 0.05) higher numbers of spermatozoa with intact acrosomes, intact membranes (HOST), and viable sperm (P < 0.01) were in semen frozen in Triladyl than in the synthetic extender. Mean values for heterologous SPA for bull (control) and for bison semen frozen in the synthetic extender were very much alike-63.3+/-10.6% and 63.1 +/- 15.9%, respectively; bison semen frozen in Triladyl was lower, 43.0+/-24.2% but not significantly different. Cumulative results from a variety of viability assays of diluted/cooled and frozen-thawed semen, including the heterologous SPA, suggest that European bison semen can be successfully frozen in both extenders tested in this study.

226 BASIC CHARACTERISTICS OF CAPTIVE BROWN BEAR (URSUS ARCTOS) SPERMATOZOA COLLECTED BY ELECTROEJACULATION AND FROM THE POSTMORTEM EPIDIDYMIS

The objective of the present study was to describe the basic characteristics of brown bear spermatozoa collected by electroejaculation and from the cauda epididymis after necropsy. Semen was collected during the mating season of 2004 and 2005 from five mature males, aged from 3.5 to 22 years. Animals were anesthetized with 7 to 10 mg/kg body weight of Zoletil® (tiletamine + zolazepam; Virbac, Carros, France). Bears were placed on a special stretcher in ventral recumbency. A rectal probe with three longitudinal electrodes and a diameter of 2 cm (Electrojac IV; Minitübe, Tiefenbach, Germany) was placed into the rectum. Two series of stimuli were administered with a 2–3 min rest between series. Each stimulus lasted 2 s and was administered at 2 s intervals increasing intensity of stimulation from 0 to 15V. Of 23 electroejaculation attempts, 17 ejaculates were collected and two were eliminated because of poor semen quality. Epididymal spermatozoa were collected from three animals after euthanasia by flushing cauda epididymis with the freezing medium. Two animals showed unilateral testicular hypoplasia and only one testicle was processed from each of them. Volumes were recorded and concentration was evaluated in the laboratory. Semen quality of epididymal and ejaculated samples was assessed by: progressive sperm motility (%IM); quality of movement on a scale of 0 to 5 (Q); normal acrosome status (%NAS) and normal sperm morphology (%NOR), assessed by phase contrast microscopy of glutaraldehyde fixed samples; membrane response to hypo-osmotic test (%HOST); and sperm viability estimated using eosin-nigrosin vital staining (%V). Results were evaluated by Student t-test. Mean volume of ejaculates was 0.79 ± 0.73 mL. The average concentration of samples collected by electroejaculation was 519 ± 278 × 106 sperm/mL. The average number of spermatozoa collected per ejaculate was lower than the average number of spermatozoa collected from the epididymis, 476 ± 352 × 106 vs. 640 ± 164 × 106, respectively (P > 0.05). Sperm quality was not different between epididymal and electroejaculated samples (Table 1), except that the %NORwas higher in electroejaculated samples than in epididymal samples (62 ± 16 vs. 3 ± 15; P < 0.01). Ahigh percentage of spermatozoa with abaxial midpiece attachment (78.6 ± 10.4%) was observed in all samples. All electroejaculates contained leukocytes and 53% of the ejaculates had agglutinated spermatozoa. All 15 ejaculate and all epididymal samples were frozen in TES-Tris extender containing 4% glycerol using a standard protocol for bull semen. Our results indicate that electroejaculated and epididymal brown bear spermatozoa may be of sufficient quality for use in AI programs to increase gene flow between isolated captive populations. Whether cryopreserved samples can be used for artificial breeding remains to be determined. Table 1. Quality parameters of spermatozoa from ejaculated and epididymal samples (mean ± SD) This work was supported by Zoological Society of San Diego.

VALIDATING A COMMERCIALLY AVAILABLE ENZYME IMMUNOASSAY FOR THE DETERMINATION OF 17β-ESTRADIOL AND PROGESTOGENS IN THE FECES OF CHEETAHS (ACINONYX JUBATUS): A CASE REPORT

Fecal 17beta-estradiol and progestogens excretion was monitored in adult, female cheetahs (Acinonyx jubatus; n = 2), ZGG-12301 (born 3 April 1993), gonadotrophin treated and ZGT-3301, (born 19 August 1993), nontreated, for 120 days using commercially available plate enzyme immunoassay kits prepared for human serum or plasma. There were significant differences (P < 0.001) between baseline and peak concentrations of both hormone measures. Female ZGG-12301, which conceived, but this pregnancy resulted in an unobserved spontaneous abortion, showed no significant difference (P > 0.05) between baseline and gestation 17beta-estradiol values; fecal 17beta-estradiol excretion during pregnancy was statistically different (P < 0.001) from excretion during the nonpregnancy period. Baseline progestogen concentrations were different from pregnancy (P < 0.001) and postovulatory (P < 0.01) concentrations, and progestogen concentrations during pregnancy period were different (P < 0.001) from postovulatory concentrations. In the nontreated cheetah (ZGT-3301), basal and increased progestogen concentrations were statistically different (P < 0.01). On the basis of 17beta-estradiol excretory patterns, duration of the estrous cycle (x +/- SEM) was 13.2 +/- 2.2 days. These results suggest that the enzyme-linked immunosorbent methods reported in this study were capable of quantifying reproductive hormones in fecal extracts of cheetahs and could be a practical alternative to other enzyme-linked immunosorbent assays which require more complex procedures.

199 BASIC CHARACTERISTICS AND CRYOBANKING OF BARBARY SHEEP (AMMOTRAGUS LERVIA) SEMEN

Barbary sheep (Ammotragus lervia) are considered vulnerable species by the World Conservation Union (IUCN). The purpose of this study was to describe the basic characteristics of fresh semen, test the efficacy of commercial extender Triladyl, and collect necessary data that may help to create a frozen semen bank for the Barbary sheep in Spain. A total of 21 ejaculates were collected by rectal-probe electroejaculation from one dominant (D) and three minor (M) adult males housed in the Madrid Zoo. After ejaculation, semen volume, concentration, and mass motility were assessed. Remaining raw semen was diluted at 37°C with TRIS-based extender Triladyl (Minitüb, Tiefenbach, Germany) and 20% egg yolk to a final concentration of 200 × 106 sperm per mL. Diluted samples were kept at 5°C for 4 h and then loaded into 0.25-mL French straws, frozen at 5 cm above liquid nitrogen (LN2) for 10 min and then plunged into LN2. Samples were thawed in a water bath at 37°C for 30 s. Post-thaw semen survival was evaluated by sperm motility (%M), quality of movement (Q), normal acrosome status (%NAS), normal sperm morphology (%NOR), membrane integrity (hypo-osmotic test; %HOST), and sperm viability (eosin-nigrosin vital staining; %V), and were compared with the same parameters in the fresh semen. Data between D and M males were analyzed by one way ANOVA. Mean volume of ejaculates, total sperm concentration and mass motility of raw semen were respectively; 5.2 ± 1.56 mL, 2800.0 ± 1290.5 × 106 and 3.4 ± 0.4 for the D male, and 3.5 ± 3.2 mL, 251.2 ± 103.9 × 106, and 1.88 ± 1.4 for M males (P < 0.05). Remaining semen parameters evaluated in raw semen showed no differences between D and M males. However, post-thaw semen quality was significantly (P < 0.05) reduced in all analyzed parameters except %NAS and %NOR in M males groups as compared to the D male (Table 1). It can be concluded that Barbary sheep raw semen collected by electroejaculation is of sufficient quality to be used in an artificial insemination program and can be successfully frozen in commercially available Triladyl extender. However, the post-thaw viability of semen may considerably depend on the male reproductive status in the flock. Table 1. Characteristics of fresh and cryopreserved Barbary sheep semen This work was supported by CAM 07B/007/1999 (Analysis of ejaculate traits and development of methods of semen preservation in wild ungulates from the Madrid Zoo).

Evaluation of three strip tests for measuring electrolytes in mares' pre-partum mammary secretions and for predicting parturition

Three strip test kits which measure calcium and/or magnesium in mares' mammary secretions were compared and assessed for their accuracy in:- 1) measuring these electrolytes compared to standard laboratory measurements, and 2) predicting the time of parturition. Daily samples of mammary secretions were obtained pre-partum from 35 Thoroughbred mares and allocated a score. Measurement of mammary secretion calcium and/or magnesium by the strip tests and laboratory methods correlated significantly (P less than 0.001). The results obtained for prediction of parturition were analysed by two methods. Method i) indicated that the majority of mares had a maximum score on the day of birth. However, the second method of analysis included all prepartum scores and this demonstrated that maximum scores occurred on more occasions prior to the day of birth than on the day of birth itself. The number of nights spent attending mares, and the percentage of occasions when foaling was missed, were also calculated for given strip test scores. The results indicate that the test kits are not particularly accurate in predicting time of parturition although they are a reliable means of measuring mammary secretion calcium and/or magnesium. It is suggested that the test kits may be more helpful by indicating when it is not necessary to attend mares at night.