Reproduction in Domestic Animals - Facultad de Ciencias Veterinarias

More documents

Recommendations

Info

$(Microsoft PowerPoint - Lecci\363n 2_07.ppt)$

16 t h International Congress on Animal Reproduction 112 Poster Abstracts P254 Effect of impaired uterine drainage via cervix in normal mares after insemination Reine, E 1 *; Reilas, T 2 ; Rivera Del Alamo, M 3 ; Katila, T 4 1Faculty of Veterinary Medicine, Latvian University of Agriculture, Latvia; 2Equine Research, MTT Agrifood Research Finland, Finland; 3 Faculty of Veterinary Medicine, Autonomous University of Barcelona, Spain; 4 Faculty of Veterinary Medicine, University of Helsinki, Finland Introduction In normal mares, the acute endometrial inflammation caused by artificial insemination (AI) peaks around 8 h and subsides appreciably within 24 h after AI. In mares susceptible to endometritis, inflammation and infection may persist because of reduced myometrial contractions. The necessity of a patent cervix has been recognized, and manual dilatation of the cervix has been used to aid evacuation of fluid collections. The roles of lymhatic drainage and drainage through an open cervix warrant further investigations. Objective To examine the role of the cervix in uterine drainage, a balloon-tipped catheter was used to impaire uterine drainage via cervix. Numbers of polymorphonuclear neutrophils (PMNs) were evaluated after AI in 3 treatments: A) AI, catheter closed for 25 h, B) AI, catheter closed for 6 + 19 h, and C) AI, no intracervical catheter. Methods Twenty-nine clinically normal mares were assigned to 4 groups and followed through 5 oestrus cycles. During the first, third and fifth oestrus, the uterus was swabbed. In the second and fourth oestrus, the mares were treated in the following order: group1) CA, group 2) AC, group 3) CB, and group 4) BC. AI dose was 500 x 10 6 progressively motile sperm extended with skim milk (20 ml, pooled semen from 2 stallions). In treatments A and B, clamped catheters were inserted immediately after AI. Uterine fluids were collected either using a tampon 25 h after AI in C (tampon fluid TF) or by draining fluid from the catheter at 25 h in A, and at 6 and 25 h in B (catheter fluid CF). Oxytocin was injected i.v. to aid fluid drainage. At 25 h, the uterus was lavaged using 500 ml of Ringer’s solution (lavage fluid LF). PMNs were counted using a Bürker chamber. Results In the second oestrus, at 25 h after AI, PMN concentrations (10 6 /ml) were similar in treatments A and B (CF-A: 73.2 ± 8.4, CF-B: 66.3 ± 19.9, LF-A: 2.4 ± 0.4, LF-B: 2.4 ± 0.8), and lower in treatment C (TF-group 1: 3.8 ± 0.5, TF-group 3: 2.9 ± 0.4). In the fourth oestrus, PMN numbers in treatment C were 10 times higher than during the second oestrus (TF-group 2: 27.7 ± 4.2, TF-group 4: 31.1 ± 12.5). In treatments A and B, PMNs were only slightly elevated compared to values in the second oestrus (CF-A: 143.3 ± 17.3, CF-B: 97.9 ± 16.7). PMNs in LF between treatments did not differ. Draining the uterus at 6 h had no effect on PMN numbers in CF 19 h later. Swabs were negative for bacterial endometritis. Conclusion Impaired cervical drainage seemed to have a profound effect on uterine inflammation showing the important role of the cervix. P255 Serum aldosterone concentrations in Spanish Purebred mares during pregnancy Satué, K*; Domingo, R Faculty of Veterinary Medicine, Cardenal Herrera-CEU University, Valencia, Spain Introduction The need to supply oxygen and nutrients to the fetoplacental unit and to counterbalance the effects induced by the release of new gonadotropic hormones during pregnancy requires important adjustments of all hormones involved in the regulation of blood volume, hydration and electrolytic state, and therefore of blood pressure. Objectives The main purposes of this research were: 1) to establish reference ranges for serum aldosterone (ALD) concentrations in Spanish Purebred mares; 2) to analyze pregnancy-related changes related to pregnancy in serum ALD concentrations and 3) to assess the effect of the age of the mare in serum ALD. Material and Methods Thirty-three Spanish Purebred broodmares, aged between 4 and 17 years were selected for this study. Jugular venous blood samples were taken every month during pregnancy in the morning. After withdrawal, blood was centrifuged and serum was harvested. Serum ALD concentrations were measured by competitive immunoassay. Results Mean serum ALD concentrations were 562.21 pg/ml, with maximum and minimum values of 1936.77 and 101.50 pg/ml respectively. Mean values in the 1 st month of pregnancy were 628.79 pg/dl, they diminished in the 2 nd month, when the minimum mean values were achieved (346.09 pg/ml). In the 3 rd and 4 th months, serum ALD progressively increased to reach maximum mean values in the 5 th month (795.19 pg/ml). From this moment on, the mean values fluctuated without significant differences up to the partum, with means comprised between 458.59 and 658.17 pg/ml. No significant differences were detected in relation to the age of the mares. Discussion The Spanish Purebred broodmares showed serum ALD concentrations higher than those described for foals and adult horses of different breeds. Most of the studies have been carried out in sport horses and it is well known that the loss of Na in sweat leads to a compensatory release of ALD. Serum ALD concentrations increased two to three-fold in pregnant women, bitches and laboratory animals. The main mechanisms involved in the increased serum ALD concentrations during pregnancy could be: release of renin and angiotensin II, and changes in ACTH concentrations. Conclusions In conclusion, pregnancy in Spanish Purebred broodmares induces a progressive increase in serum ALD concentrations. This finding might imply a better conservation of Na and water in the kidneys in order to favor the expansion of the fetoplacental barrier. In this way, a suitable supply of nutrients and oxygen to the fetus as well as a correct blood pressure would be guaranteed, contributing to the internal homeostasis of the fetus and the mare. In addition, this result could be a consequence of the interaction of several neuroendocrine factors during pregnancy. P256 The duration of the effects of active immunization against GnRH to suppress ovarian activity in mares in South Africa Schulman, ML*; Botha, AE; Bertschinger, HJ; Guthrie, AJ Faculty of Veterinary Science, University of Pretoria, South Africa Introduction A GnRH-vaccine to suppress reproductive function was administered to a large group of horse mares. The effects of vaccination on ovarian activity were monitored over a period of one year using serum progesterone concentration (SPC). Methods Sixty five cyclic mares (age range: 3 to 24 years) were assigned randomly in the middle of the summer season to either a control (Group C, n = 10) or an experimental (Group E, n = 55) group, respectively. Both groups were subdivided into three age categories: Category 1 (3 to 5 years), Category 2 (6 to 14 years), and Category 3 (> 15 years). On Day 0, all mares were examined by transrectal palpation and ultrasound to establish their reproductive status. Group E mares were injected intramuscularly with 2 mL of GnRHvaccine (Improvac ® , Pfizer Laboratories, Sandton, SA). Group C mares similarly received an equal volume of sterile normal saline solution. The injections were repeated on Day 35, and the clinical examinations on Days 35, 70 and 260. The last examination corresponded approximately with the onset of the following summer season. Blood samples were collected at weekly intervals from Day 0 until Day 360 from all mares for SPC using a radioimmunoassay kit 125 (Progesterone Coat-a-Count, Diagnostic Products Corp, Los Angeles, CA, USA). As the SPC results correlated significantly with the clinical findings, SPC alone was used to monitor ovarian activity from Day 260 until 360. All data was analyzed using NCSS software (Number Cruncher Statistical Systems, Kaysville, UT, USA) and a multivariate analysis of variance (ANOVA) assessed the effects of treatment and age on clinical parameters and SPC. Values were considered to be statistically significant at P < 0.05. Results On Day 0, all Group C and E mares showed clinical evidence of ovarian activity. On Day 35, all Group C and 8 (14.5 %) Group E mares showed ovarian activity. The SPC results showed all Group E mares were non-cyclic by Day 56. On Day 70, examination and SPC indicated all Group C, and none of Group E mares showed ovarian
16 t h International Congress on Animal Reproduction Poster Abstracts 113 activity. All Group E mares remained in anoestrus until Day 175 with SPC < 1 nmol/L. No effect of age category on suppression of cyclicity within Group E was observed. On Day 260, only two (4 %) of the 48 Group E mares remaining in the trial were cyclic. On Days 280, 300, 320, 340 and 360, the number of cyclic mares was: 4 (8 %), 11 (23 %), 18 (38 %), 23 (48%) and 27 (56 %), respectively. A significant age effect on the resumption of cyclicity was observed between Category 3 and the other two age categories. Conclusions All mares responded rapidly after immunization against GnRH with complete suppression of cyclic activity for a minimum of 175 days, with 56 % resuming cyclic activity within one year of vaccination. P257 Effect of seminal plasma on the fertilizing capacity of stallion epididymal sperm Stout, TAE*, Sostaric, E; Kraan, H Department of Equine Sciences, Utrecht University, Netherlands The epididymis plays important roles in sperm maturation and storage and, in the event of death or castration, represents a potentially useful source of male germ plasm. However, while pregnancies have been obtained in mares inseminated with frozen-thawed epididymal sperm, success rates have been disappointing. This study aimed to determine: at what point during epididymal transit stallion sperm acquire the ability to acrosome react; whether cauda epididymal sperm are as capable of capacitating and acrosome reacting as ejaculated sperm and, if not, whether this can be rectified by exposure to seminal plasma. In Experiment 1, spermatozoa recovered from the caput, corpus and cauda epididymides were incubated under capacitating conditions; aliquots were then exposed to progesterone or calcium ionophore (A23187) to induce the acrosome reaction (AR). AR and viability were examined by staining with fluorescein-conjugated peanut agglutinin (PNA-FITC) and propidium iodode. Only cauda epididymal sperm were able to undergo the AR in appreciable quantities in response to progesterone (7 %) or calcium ionophore (17 %). In Experiment 2 an ejaculate was recovered from nine stallions at daily sperm output; the sperm and seminal plasma were separated by centrifugation. The stallions were then castrated and the sperm flushed from the cauda epididymides and divided into two portions, one of which was pre-incubated for 30 mins with homologous seminal plasma. Three experimental groups were thus created; i) ejaculated sperm (Ej); ii) epididymal sperm (E) and iii) epididymal sperm exposed to seminal plasma (Es). After washing, sperm from all 3 groups were incubated under capacitating conditions. At intervals during incubation, aliquots were examined for evidence of capacitation (tyrosine phosphorylation and progesterone receptor exposure) and the AR. After incubation for 2 or 4 hours, significantly higher percentages of ejaculated than epididymal sperm showed evidence of tyrosine phosphorylation, the AR (p
Page 1 and 2:
REPRODUCTION IN DOMESTIC ANIMALS 43
Page 3 and 4:
16th International Congress on Anim
Page 5 and 6:
16 t h International Congress on An
Page 7 and 8:
Page 9 and 10:
Page 11 and 12:
Page 13 and 14:
Page 15 and 16:
Page 17 and 18:
Page 19 and 20:
Page 21 and 22:
Page 23 and 24:
Page 25 and 26:
Page 27 and 28:
Page 29 and 30:
Page 31 and 32:
Page 33 and 34:
Page 35 and 36:
Page 37 and 38:
Page 39 and 40:
Page 41 and 42:
Page 43 and 44:
Page 45 and 46:
Page 47 and 48:
Page 49 and 50:
Page 51 and 52:
Page 53 and 54:
Page 55 and 56:
Page 57 and 58:
Page 59 and 60:
Page 61 and 62:
Page 63 and 64: 16 t h International Congress on An
Page 113: 16 t h International Congress on An
Page 165 and 166:
Page 167 and 168:
Page 169 and 170:
Page 171 and 172:
Page 173 and 174:
Page 175 and 176:
Page 177 and 178:
Page 179 and 180:
Page 181 and 182:
Page 183 and 184:
Page 185 and 186:
Page 187 and 188:
Page 189 and 190:
Page 191 and 192:
Page 193 and 194:
Page 195 and 196:
Page 197 and 198:
Page 199 and 200:
Page 201 and 202:
Page 203 and 204:
Page 205 and 206:
Page 207 and 208:
Page 209 and 210:
Page 211 and 212:
Page 213 and 214:
Page 215 and 216:
Page 217 and 218:
Page 219 and 220:
Page 221 and 222:
Page 223 and 224:
Page 225 and 226:
Page 227 and 228:
Page 229 and 230:
Page 231 and 232:
Page 233 and 234:
show all

Reproduction in Domestic Animals - Facultad de Ciencias Veterinarias

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?