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 208 Poster Abstracts |Both groups were kept together under the same management conditions. Fifty days after embryo transfer, the pregnancy diagnosis was performed. Results- The group of seropositive recipient heifers showed a pregnancy rate of 72.7% and the seronegative group a pregnancy rate of 81.8%. There was no significant difference between them. Conclusions- There was no interference of Neospora caninum infection on the pregnancy rates of embryo recipient heifers during the first third of the gestation period. P546 Alleviation of maternal hyperthermia-induced early embryonic death by administration of DL-α-tocopherol acetate accompanied by a reduction of physiological oxidative stress in mice Ozawa, M 1 *, Sakamoto, N 2 , Yokotani-Tomita, K 2 , Morimoto, A 2 , Ijiri, D 2 , Hirabayashi, M 2 , Ushitani, A 2 , Yukio, K 2 1Division of Animal Sciences, Reproductive Biology, National Institute of Agrobiological Sciences, Japan; 2 Graduate School of Life and Environmental Science, University of Tsukuba, Japan Maternal hyperthermia induces pre-implantation embryo death, which is accompanied by enhanced physiological oxidative stress. We evaluated whether the administration of DL-α-tocopherol acetate (TA) to hyperthermic mothers mitigated pre-implantation embryo death. Mice were exposed to heat stress (35°C, 60% relative humidity) for 12 h or not heated (25°C) on the day of mating. Twelve hours before beginning the temperature treatment, TA was injected intraperitoneally at a dose of 1 g/kg body weight. After the treatment, zygotes were recovered and the developmental abilities and intracellular glutathione (GSH) levels were evaluated. Another set of mice, with or without TA treatment, was exposed to heat stress for 12, 24, and 36 h and the urinary levels of the oxidative stress marker 8- hydroxy-2’-deoxyguanosine (8-OHdG) were measured. Heat stress significantly decreased the blastocyst development rate and the GSH content in zygotes, as compared to the non-heat-stressed embryos, while TA administration significantly mitigated the deleterious effects of heat stress with regard to both parameters. Moreover, although the urinary levels of 8-OHdG gradually increased according to the duration of heat exposure, with or without TA administration, the levels were lower in the TA-administered group than in the placeboinjected mice. These results suggest that heat stress enhances physiological oxidative stress, and that TA administration alleviates the hyperthermia-induced death of pre-implantation embryos by reducing physiological oxidative stress. P547 Heat shock-induced damage in bovine oocytes Paula-Lopes, FF 1 *, Milazzotto, MP 1 ; Assumpção, MEOA 1 ; Visintin, JA 1 1 Department of Animal Reproduction, School of Veterinary Medicine and Animal Sciences, University of São Paulo, Brazil The series of events associated with oocyte growth and maturation are susceptible to disruption by elevated temperature compromising the ability of the oocyte to undergo adequate fertilization and embryonic development. The objective of the current study was to examine whether exposure of bovine oocytes to a physiological heat shock (HS) during IVM induces cell death and compromises oocyte developmental competence. In the first study slaughterhouse crossbred Bos indicus cumulus-oocyte complexes (COCs) were exposed to control (39°C for 22 h) or HS (41°C for 12 h followed by 39°C for 10 h) during IVM. Approximately 22 h after IVM oocytes were denuded (1 mg/ml hyaluronidase) and subjected to a membrane permeability based triple staining using 5 µg/ml Hoechst 33342, 1 µg/ml propidium iodide (PI) and 2.5 µM YO-PRO1 as DNA staining markers for live, necrotic and apoptotic cells, respectively. Exposure of bovine oocytes to HS during IVM reduced the proportion of oocytes that reached the metaphase II stage (61.43 + 6.25 and 30.13 + 6.25% for control and HS, respectively; p< 0.05). This experiment was replicated 5 times using a total of 152-161 COCs/treatment. Even though HS compromised oocyte nuclear maturation there was no effect on the proportion of necrotic and apoptotic oocytes. In the second experiment COCs were exposed to control or HS temperatures as described in experiment 1. Oocytes were subjected to in vitro fertilization and culture at 39°C. Heat shock reduced the proportion of oocytes that cleaved (62.90 + 2.06 and 49.64 + 2.06% for control and HS, p< 0.0001) and reached the blastocyst stage (20.01 + 1.08 and 7.41 + 1.14 % for control and HS; p< 0.0001). This experiment was replicated 10 times using a total of 1309-1042 COCs/treatment. A blastocyst subset harvested from 4 random replicates (n=65 and 25 blastocyst/treatment for control and HS) was subjected to the membrane permeability based triple staining as described in experiment 1. Exposure of bovine oocytes to HS did not affect blastocyst cell number or the percentage of necrotic cells/blastocyst. However, HS increased the proportion of apoptotic cells/blastocyst (8.75 + 1.14 and 13.00 + 1.71% for control and HS, respectively; p< 0.05). Therefore, exposure of bovine oocytes to a physiological HS during IVM compromised oocyte maturation and developmental competence. However, such moderate HS did not induce oocyte apoptosis or necrosis. In conclusion, direct exposure of crossbred Bos indicus oocytes to a physiological HS compromised the oocyte machinery without inducing oocyte death. (Support: CNPq). P548 Efficacy of 18 and 36 mg subcutaneous melatonin implant to reversibly suppress estrus in queens Stornelli, MA 1 *, Giménez, F 1 , Stornelli, MC 1 , Savignone, CA 1 , Tittarelli, C 1 , Videla Dorna, I 2 , De La Sota, RL 1 1Servicio y Cátedra de Reproducción Animal, Facultad de Ciencias Veterinaria. Universidad Nacional de La Plata, Argentina; 2 Syntex SA, Argentina The aim of this study was to assess the efficacy of 18 and 36 mg subcutaneous melatonin implant (SMI) to reversibly suppress estrus in queens. Fourteen queens aged between 12 and 14 months and weighting between 2 and 4 kg were maintained under artificial illumination (14 h light: 10 h dark) and assigned to one of two treatments (TRT). At interestrus (IE), queens assigned to TRT18 received a SMI (18 mg; Syntex SA, Argentina; =7), and queens assigned to TRT36 received SMI (36 mg; Syntex SA, Argentina; n=7). Blood samples were taken when queens showed proestrus signs (PE) to measure E2 by RIA. Before implant administration and once a month during IE, blood samples were taken to measure P4 by RIA and melatonin (MEL) by ELISA. After the trial was concluded, ten queens were mated and pregnancy was diagnosed by ultrasonography 20 days after mating. No significant differences in IE length, serum MEL concentration, or the area under the curve were detected between TRT18 and TRT36 queens (65.0±14.9 vs. 65.6±13.4 d, P>0.97; 42.6 vs. 45.6 vs. 9.4, P>0.89; 2682±726 vs. 2732±593, P>0.95). A significant rice in serum MEL concentration was observed after implant insertion in both TRT (before vs. after insertion, 30.2 vs. 43.8±2.9 pg/ml, P0.27). E2 serum concentrations were similar between TRT18 and TRT36 implants (E2, 54.9±10.7 vs. 60.1±9.6 pg/ml, P>0.73). On the contrary, a significant difference in serum P4 concentrations was detected. On day of implant insertion, serum P4 concentrations were higher than 4 ng/ml in 6 of 14 queens studied and decreased below 1 ng/ml around 19.6±13.4 d of implant insertion in both groups (TRT18 [n=1] vs. TRT36 [n=5], P>0.39). During this period serum P4 concentrations were similar for both groups (P>0.11). In the other 8 queens no significant differences in serum P4 concentrations were detected between TRT (P>0.46) and concentrations were below 1 ng/ml during the study period. Although spontaneous ovulation and pseudopregnancy may explain high P4 concentrations (>4 ng/ml) and non return to estrus during the first 19 d of IE, after day 19MEL concentrations from the implant were responsible maintaining the non return to estrus from day 19 onwards in these 6 queen. The pregnancy rate to the first mating was 60% (6/10). Thus, both MEL implants were equally effective to temporarily and reversibly suppress estrus in queens for two months with no side effects. Key words: queen; reversible contraception; melatonin
16 t h International Congress on Animal Reproduction Poster Abstracts 209 P549 Effects of husbandry practices and animal welfare on reproductive indicators in sheep Veksler Hess, J.*; Schuh, A.; Coppola, M.; Decaminada, E.; Miralles, M.; Ghirardi, M. Department of Veterinary Sciences; University of Buenos Aires. Buenos Aires. Argentina With the purpose of evaluating the influence of husbandry practices and animal welfare on reproductive indicators in sheep we determined the impact of both factors on a Romney Marsh pure- breed flock in a farm in “General Lavalle”, Buenos Aires, in a region known as “Cuenca del Salado”. We evaluated the effects of two treatments (A and B) on a flock of 50 ewes (n=50) ranging from 19-30 months of age, with a Body Score of 3.5 (Scale 1-5). Both treatments received the same sanitary and reproductive management, with natural service using 2% rams. In treatment A, husbandry practices followed the Animal Welfare regulations (Thirsty-free; hunger-free; comfortability, free of fear and stress). The diet during the maximum requirement stages (mating, G2, milking) consisted of Lotus tenui, Trifolium repens and Lolium perenne. Treatment B differed from A in husbandry practices and nutritional management. This treatment not corresponded with the University\'s animal welfare rules. The basic regulations of animal welfare were not followed (change of personnel, aggressive treatment of animals, inadequate facilities and herding, etc.). In treatment B the diet consisted of a natural pasture composed primarily of Distichlis spicata, a graminea frequently found everywhere in Buenos Aires province, preferably in salty and humid soils, due to its salinity tolerance. Its nutritional value is acceptable but since it is a small plant, its forrage offer is scarce. In treatment B the requirements of the different productive stages were not taken into account and the ewes grazed always in the same paddocks. Method A resulted in 42 finished lambs (n=42) which represented 113% lambing rate. Method B resulted in 35 lambs (n=35); 70% lambing rate. Significant differences were observed (p0.05) of the initially normal follicles remained intact after cryopreservation. But the proportions of the degenerated follicles were significantly increased after freezing. Conclusion Our results suggest that cryoprotective solution is toxic for the preantral follicles. Moreover, freezing solution composed of PROH seems to be more adapted to the cryopreservation of bovine ovarian tissue. Nevertheless, evaluation of such freezing solution needs to be performed in a larger population. (Grant from Region Rhône-Alpes)
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:
Page 65 and 66:
Page 67 and 68:
Page 69 and 70:
Page 71 and 72:
Page 73 and 74:
Page 75 and 76:
Page 77 and 78:
Page 79 and 80:
Page 81 and 82:
Page 83 and 84:
Page 85 and 86:
Page 87 and 88:
Page 89 and 90:
Page 91 and 92:
Page 93 and 94:
Page 95 and 96:
Page 97 and 98:
Page 99 and 100:
Page 101 and 102:
Page 103 and 104:
Page 105 and 106:
Page 107 and 108:
Page 109 and 110:
Page 111 and 112:
Page 113 and 114:
Page 115 and 116:
Page 117 and 118:
Page 119 and 120:
Page 121 and 122:
Page 123 and 124:
Page 125 and 126:
Page 127 and 128:
Page 129 and 130:
Page 131 and 132:
Page 133 and 134:
Page 135 and 136:
Page 137 and 138:
Page 139 and 140:
Page 141 and 142:
Page 143 and 144:
Page 145 and 146:
Page 147 and 148:
Page 149 and 150:
Page 151 and 152:
Page 153 and 154:
Page 155 and 156:
Page 157 and 158:
Page 159 and 160: 16 t h International Congress on An
Page 209: 16 t h International Congress on An
show all

Reproduction in Domestic Animals - Facultad de Ciencias Veterinarias

Create successful ePaper yourself

Delete template?

Save as template?