Reproduction in Domestic Animals - Facultad de Ciencias Veterinarias

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16 t h International Congress on Animal Reproduction 126 Poster Abstracts be due to intrauterine inseminations at two different points. In the future studies, it is suggested that, non-surgical intrauterine insemination techniques are needed to be tried in queens. P297 Assessment of reproductive histology and sex steroid receptor expression in the domestic cat (Felis catus) following chronic exposure to phytoestrogens Bell, K 1 *, Ugarte, CE 1 , Tucker, LA 2 , Roe, WD 3 , Thomas, DG 1 1Institute of Food Nutrition and Human Health, Massey University, New Zealand; 2 Waiti Hill, New Zealand; 3 Institute of Veterinary Animal Biomedical Sciences, Massey University, New Zealand Phytoestrogens are secondary plant compounds, incorporated into commercially prepared felid diets through the use of soy-derived ingredients. The phytoestrogens genistein and daidzein, have been shown to elicit changes in reproductive tract histology and sex steroid receptor expression in a variety of mammalian species. These phytoestrogens are considered to be potential aetiological agents in the infertility suffered by a large percentage of the captive cheetah (Acinonyx jubatus) population. To investigate this hypothetical role in felid reproduction, domestic cats (n = 6; 4 female, 2 male) were exposed to dietary genistein and daidzein (300µg/g DM total isoflavones) from weaning (8 weeks of age) until approximately 15 months of age. A control group of related cats (n = 10, 8 female, 2 male) were reared under identical conditions and fed the same diet without the addition of phytoestrogens. Reproductive tracts were collected from all animals during routine gonadectomy and processed for histological and immunohistochemical analysis (IHC). Tissues were collected from female animals (mean age 485 days) during interoestrous as assessed by vaginal cytology, and from male animals at 350 days of age. Reproductive tracts were assessed for histopathological changes, and other parameters including uterine luminal epithelial cell height and follicular development in females. The expression and distribution of Estrogen Receptor (ER)-α, ERβ and Progesterone Receptor (PR) was assessed in ovarian and uterine tissue using IHC techniques. Wet weight of the reproductive tracts did not differ between groups and all but one tract (treatment group) were within normal expected range of inflammatory cell infiltration. Luminal epithelial cell height was greater in treatment animals (5.39µm vs. 4.36µm; p < 0.05) but no differences were detectable in ovarian histology. Expression of ERα and ERβ was up-regulated in the tracts of treatment animals, whilst PR expression was generally down-regulated, compared to controls (p < 0.05). Tissue- and receptor-specific variation was apparent. Although isoflavones were not found to be uterotrophic, the observed histological changes were suggestive of oestrogenic activity. Furthermore, the ability of isoflavones to modulate the proportional expression of sex steroid receptors may have implications for fertility and fecundity in later life. Future investigations in domestic cats utilising larger sample sizes, regimes including in utero and/or lactational exposure and controlled fertility and fecundity testing are warranted. P298 The effect of GnRH on fertility of alpacas inseminated with frozen-thawed semen Bravo, W 1 *, Ramos, A 2 , Alarcon, V 3 , Ordoñez, C 2 1Camelid Veterinary Services, United States; 2 Centro Experimental La Raya, Universidad Nacional San Antonio Abad, Cusco, Peru; 3 Facultad de Agronomia y Zootecnia, Universidad Nacional San Antonio Abad, Cusco, Peru between the three groups, with 72.6% of females ovulating. There was no significant difference in pregnancy at 21 days between the two dosages of GnRH, with 75%, and 76.2% of females being pregnant for 0.1 μg and 1.0 μg GnRH, respectively; however, 65% of females of the control group were pronounced pregnant, which is significantly different than the females that received GnRH (P 0.05). Lower ERα and PR scores (P < 0.05) and higher numbers of leukocytes (P < 0.05) were observed in the pyometra groups than the normal bitches. Differences of the ERα and PR scores were not seen between the open- and closed-cervix pyometra (P > 0.05) whereas higher number of neutrophils was found in the open-cervix than closed-cervix pyometra (P < 0.05). Conclusions The ERα and PR expressions in the cervix of dogs are influenced by stages of the oestrus cycle. Neutrophils infiltration in the cervical tissue appears to involve in cervical dilatation in pyometra bitches. Gonadotropin releasing factor (GnRH) was used immediately after artificial insemination with frozen-thawed semen in alpacas. GnRH diluted in Tris buffer was deposited in the uterine horn ipsilateral to the ovary containing an ovulatory-sized follicle. Ovulation was induced with hCG (Chorulon, Intervet) 24 hours before artificial insemination in 157 adult female alpacas that were divided into three groups: 58 control, 43 with 0.1 μg GnRH, and 56 with 1 μg of GnRH (Fertagyl, Intervet). There was no difference in ovulation percentage
16 t h International Congress on Animal Reproduction Poster Abstracts 127 P300 Acrosin activity evaluation in chilled/rewarmed dog sperm during different capacitation times De Los Reyes, M*, Godoy, N; Palomino, J Animal Production, Animal Reproduction Unit, Faculty of Veterinary Sciences, University of Chile, Chile Introduction The acrosome reaction causes release of acrosin, a proteolytic enzyme that facilitates sperm penetration through the zona pellucida. The release of acrosin on in vitro capacitated chilled/rewarmed canine spermatozoa is a time depending process. Thus, the aim of the present work was to study the proteolytic acrosin activity in chilled/rewarmed canine spermatozoa during in vitro capacitation and acrosome reaction. Methods Six ejaculates were collected from four adult dogs. Each ejaculate was liquated into 2 fractions and centrifuged in tris buffer medium. The pellet of one fraction was diluted in fert-talp medium (fresh control sample), and the pellet of the other fraction was diluted in a tris-fructose-citric acid and egg-yolk extender and then cooled at 4º C for 24 h. Sperm samples (fresh and chilled/rewarmed) were centrifuged and the pellet rediluted in fert-talp medium and then aliquoted into four tubes which were incubated separately for 0, 1, 2 and 3 h at 20º. At each time of cultured, acrosin activity was measured by the gelatin-substrate film technique, where enzyme activity is detected by the presence of halos around single sperm resulting from a localized proteolytic digestion of gelatin. Gelatin suspension was placed on pre-cooled slides and fixed in 0.05% glutaraldeyde, washed and kept overnight. Sperm suspensions were placed on the slices and incubated at 38°C in CO2 for 24 h. Slices were stained with Comassie Blue and examined with light microscopy for evidence of digestion. Results Fresh and chilled dog spermatozoa incubated for up to 3 h in fert-talp medium, displayed digestion halos on gelatin films. Those digestion halos were of three different mean sizes: small, medium and large. Acrosin activity as measured by halo diameter on slides coated with gelatin, showed a significant difference between fresh and chilled sperm. A low proportion of large halos was observed in fresh samples at the beginning of culture (time 0 and 1), while chilled sperm showed a high rate of large halos at these times. During the following hours (2 and 3) of culture, fresh sperm showed higher rates of large halos than fresh sperm. Conclusion These results indicate that acrosomal proteolytic activity of chilled/ warmed dog sperm is different throughout the time from that of the control fresh sperm Supported by Grant FONDECYT 1060602. P301 Terminating pregnancy in bitches: compartive study of side effects between four treatments Fila Varela, D 1 *, Berglavaz, A 2 , de Leon, J 3 , Navarro, G 3 , Morgades, D 2 , Pereira, O 3 , Elhordoy, D 1 , Cavestany, D 1 1Animal Reproduction Department, Veterinary Faculty, Uruguay; 2 Private Practitioner, Don Quijote Veterinary, Uruguay; 3 Private Practitioner, Zoolymar Vet, Uruguay To compare incidence of side effects in four medical treatments to terminate unwanted pregnancies. 166 bitches were assigned to different treatments: Group A: (n=38) aglepristone (Alizine, Virbac, France) (10 mg/kg), two s.c. injections, 24 hours apart, around 25 to 30 days of gestation; Group D: (n=44) dexamethasone orally (0,2 mg/kg two times per day, by 5 days and then 0,1 mg/kg two times per day, during 5 more days) around 28 to 30 days of gestation; Group E: (n=45) estradiol (0,01mg/kg) intramuscularly within 48 hours of mated; and Group L: (n=39) lotrifen (Privaprol, FATRO, Italy) (2,5 mg/kg) intramuscularly within 15 days of mated. In group A, there were no side effects. In group D, the side effects were mild polydipsia and polyuria that disappeared when treatment was discontinued. Moreover, 7 of 44 bitches (15,91%) presented bloody vaginal discharge during 7 days after treatment ended, without general symptoms. In group E, 12 of 45 bitches (26,67%) developed cystic endometrial hyperplasia-pyometra that forced ovary-hysterectomy. In group L, 18 of 39 bitches (46,15%) developed cystic endometrial hyperplasia-pyometra that forced ovary-hysterectomy. Data were analyzed using X2 test and differences within treatments were considered significant when p 0.05). They occurred in 6/6, 3/3, 5/6 and 5/6, 2/3, 4/5 of the animals of the DA, DA&ACY and DA&ACY+2 groups, respectively. Estrous response appeared 5.0 ± 1.2, 10 ± 1.0 and 24.2 ± 11.7 days after treatment in the same groups (P = 0.1). Conclusions The GnRH antagonist, acyline, administered at two different time points after a GnRH agonist failed to prevent estrous response in most of these anestrous bitches. Although, in the antagonist treated groups, estrous response had a tendency to appear later. These findings suggest a postponement of the stimulation period during the peak antagonistic effect. Further studies with repeated or higher doses of antagonists are necessary. Acknowledgements This study was funded by the National Agency for Scientific and Technological Promotion, Argentina (Grant PICT 38376/05). The authors thank to NICHHD, NIH, USA and Peptech, Australia for drug provision. References Wright PJ, et al. 2001. The Suppression by Progestin of Oestrus Responses of the Bitch to the GnRH Analogue Deslorelin. J Reprod Fertil. 57: 283-8. P303 Distribution of active mitochondria in canine oocytes is related to reproductive cycle stage but can be damaged during IVM culture Iorga, AI*; Valentini, L; De Santis, T; Ambruosi, B; Guaricci, AC; Caira, M; Dell’Aquila, ME Department of Animal Production, University of Bari, Italy Introduction We investigated the effect of the reproductive cycle stage on the distribution of active mitochondria in canine oocytes examined 1) at collection and 2) after in vitro maturation (IVM). Methods Cumulus-oocyte complexes (ooplasmic size >120 µm in diameter) were recovered from 20 bitches divided into five groups
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Reproduction in Domestic Animals - Facultad de Ciencias Veterinarias

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