Reproductive efficiency of adult and prepubertal goats subjected to repeated follicular aspiration

The objective of this study was to assess the reproductive response of adult and prepubertal goats subjected to repeated laparoscopic ovum pick-up (LOPU). The study animals were divided into two groups, specifically, adult nanny goats (GA, n=10) and prepubertal nanny goats (GP, n=10), which were subjected to estrous synchronization and ovarian stimulation for LOPU. Both groups underwent six LOPU procedures at seven-day intervals and were subsequently subjected to controlled mating and pregnancy diagnosis to evaluate their future fertility. The study showed a reduction in the number of follicles visualized and in the amount and quality of the oocytes that were recovered and exposed to in vitro maturation. As indicated by the fertility test, however, no complications were found during the laparoscopic procedures that would impair the reproductive future of the animals. Therefore, a viable number of oocytes were obtained even with the decreased reproductive efficiency, proving that repeated LOPUs do not interfere with the reproductive of adult and prepubertal nanny goats. These results indicate a positive aspect of this procedure, allowing for increasing reproductive performance of this kind, when used for the production in vitro.

Biologia reprodutiva de fêmeas de laetacara araguaiae (labriformes: cichlidae)

Pós-graduação em Ciência e Tecnologia Animal - FEIS

Sincronização de receptoras no diestro para utilização em programa se transferência de embriões em equinos

Pós-graduação em Medicina Veterinária - FMVZ

Glucose, Cholesterol, Total Protein and Growth Factor Insulin-like Type I in Follicular Fluid of River Buffaloes (Bubalus bubalis)

In order to establish the concentrations of glucose, cholesterol, total protein and growth factor insulin-like type I (IGF-I) in the follicular fluid, 26 Murrah breed river buffaloes, between 45 and 70 days postpartum, empty, multiparous, with average live weight of 675 +/- 56 kg and average body condition of 3.5 points on a scale of 1-5, were used in this study. The fluid was collected from dominant follicles with diameters between 8 and 12 mm by OPU, and was not taken into account the stage of the estrous cycle. Using this technique, the wave of follicular development was synchronized six days prior to collection. Biochemical analysis was performed to glucose and cholesterol through the enzymatic colorimetric method using commercial kit glicose CHOLESTEROL GOD-PAP and CHOD-PAP (Kovalent), respectively. Determination of total protein was carried out by using total protein commercial kit (Kovalent) Biuret method, and the readings were performed using absorption spectrophotometry with visible light. Concentration of IGF-I was measured by Radioimmunoassay (RIA) technique using commercial IRMA Kit IGF-I (INMUNOTECH). Descriptive statistics were developed using the PROC MEANS procedure of SAS (2009). Concentration of glucose (4.0 +/- 0.75 mmol / L-1) and IGF-I (340 +/- 129.83 ng / mL (-1)) were higher than those reported by other authors in river buffaloes and cows, respectively. However, cholesterol levels (0.51 +/- 0.12 mmol / L (-1)) and total protein (58.4 +/- 4.43 g / L (-1)) behaved inferior to other studies in same species. The results indicated that there is relationship among the nutritional aspects, diameter of follicles aspirated and productive period in the concentration of biochemical indicators.

In vivo embryo production in cows superovulated 1 or 2 days after ovum pick-up

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The Occurrence of Autophagic Cell Death in the Tegument of Rabbits Pre-Infested with Rhipicephalus sanguineus and Exposed to Selamectin (Active Principle of Acaricide Pfizer Revolution (R))

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Relationships between growth of the preovulatory follicle and gestation success in lactating dairy cows

This report summarizes three studies conducted with lactating dairy cows aiming to increase pregnancy rates to fixed time artificial insemination (TAI) protocols. Experiment 1 was designed to determine if changing the timing of PGF2 alpha treatment during an E2/P4-based program would affect fertility to TAI or fixed-time embryo transfer (TET). In experiment 2, pregnancy rates to AI were compared following synchronized ovulation using two protocols that have been developed to reduce the period between follicular wave emergence and TAI. The Ovsynch-type protocol utilizes GnRH to synchronize the follicular wave by inducing ovulation of a dominant follicle at the beginning of the protocol, and to synchronize ovulation at the end of the protocol allowing TAI. In contrast, E2/P4-based protocols utilize E2 products in the presence of P4 to induce atresia of antral follicles and synchronize emergence of a new follicular wave. At the end of E2/P4-based protocol another E2 treatment in the absence of P4 is used to induce LH release and synchronize ovulation and allow TAI. Experiment 3 was designed to determine whether increasing the length time interval with reduced circulating P4 (proestrus) would increase fertility in a TAI program that utilized E2 and P4 to synchronize ovulation of cycling, lactating dairy cows. The overall conclusions are that circulating concentrations of progesterone and estradiol prior to and circulating concentrations of progesterone following ovulation can affect fertility in cattle. In addition, small increases in P4 concentrations near the time of AI, due to lack of complete CL regression, result in reductions in fertility. Earlier treatment with PGF2 alpha should allow greater time for CL regression, an increase in estradiol and subsequent reductions in circulating P4 that could be critical for fertility. Optimization of follicle size in TAI programs is clearly an intricate balance between oocyte quality, adequate circulating E2 near AI, and adequate circulating P4 after AI.

Effect of follicle age on conception rate in beef heifers

The objective of this study was to determine the effect of age of the ovulatory follicle on fertility in beef heifers. Ovulation was synchronized with the 5 d CO-Synch + controlled intravaginal drug release (CIDR) program in heifers in Montana (MT; n = 162, Hereford and Angus Crossbred) and Ohio (OH; n = 170, Angus Crossbred). All heifers received estradiol benzoate (EB; 1 mg/500 kg BW, [i.m.]) 6 d after the final GnRH of the synchronization program to induce follicular atresia and emergence of a new follicular wave (NFW) followed by prostaglandin F2 alpha (PGF(2 alpha); 25 mg, i.m.) administration either 5 d (young follicle [YF]; n = 158) or 9 d (mature follicle [MF]; n = 174) after EB. Estrous detection was performed for 5 d after PGF(2 alpha) with AI approximately 12 h after onset of estrus. Ovarian ultrasonography (MT location only) was performed in YF and MF at EB, 5 d after EB, PGF(2 alpha), and AI. Heifers in MT (n = 20) and OH (n = 18) that were not presynchronized or did not initiate a NFW were excluded from further analyses, resulting in 142 and 152 heifers in MT and OH, respectively. Heifers from the MF treatment in MT that initiated a second NFW after EB but before PGF(2 alpha) (MF2; n = 14) were excluded from the primary analysis. In the secondary analysis, the MF2 group was compared to MF and YF treatments in MT. Estrous response was similar (90%; 252/280) between treatments and locations. Proestrus interval (from PGF(2 alpha) to estrus) and age of the ovulatory follicle at AI were similar for MF heifers between locations (54.6 +/- 1.7 h and 8.3 +/- 0.07 h) but were greater (P < 0.01) for YF heifers in OH (78.5 +/- 1.4 h and 5.3 +/- 0.06 h) than MT (67.4 +/- 1.6 h and 4.8 +/- 0.06 h; treatment x location, P < 0.01). However, conception rate did not differ for MF (63.8%; 74/116) and YF (67.0%; 91/136) treatments. In the MT heifers, follicle size and follicle age atAI in the YF treatment (10.4 +/- 0.15 mm and 4.8 +/- 0.06 d, respectively) was less (P < 0.01) than in the MF treatment (11.0 +/- 0.18 mm and 8.3 +/- 0.11 d, respectively), but conception rate to AI did not differ between treatments in MT. In the MF2 group proestrus interval was greater (P < 0.01); hence, diameter of the ovulatory follicle and age were similar to that for the YF treatment. Conception rate to AI did not differ between MF2, MF, and YF (61.5, 63.3, and 64.7%, respectively) in MT. In conclusion, manipulation of age of the nonpersistent ovulatory follicle at spontaneous ovulation did not influence conception rate.

Characterisation of the methylation pattern in the intragenic CpG island of the IGF2 gene in Bos taurus indicus cumulus cells during in vitro maturation

The aim of this study was to characterise the methylation pattern in a CpG island of the IGF2 gene in cumulus cells from 1-3 mm and a parts per thousand yenaEuro parts per thousand 8.0 mm follicles and to evaluate the effects of in vitro maturation on this pattern.Genomic DNA was treatment with sodium bisulphite. Nested PCR using bisulphite-treated DNA was performed, and DNA methylation patterns have been characterised.There were no differences in the methylation pattern among groups (P > 0.05). Cells of pre-IVM and post-IVM from small follicles showed methylation levels of 78.17 +/- 14.11 % and 82.93 +/- 5.86 %, respectively, and those from large follicles showed methylation levels of 81.81 +/- 10.40 % and 79.64 +/- 13.04 %, respectively. Evaluating only the effect of in vitro maturation, cells of pre-IVM and post-IVM COCs showed methylation levels of 80.17 +/- 12.01 % and 81.19 +/- 10.15 %.In conclusion, the methylation levels of the cumulus cells of all groups were higher than that expected from the imprinted pattern of somatic cells. As the cumulus cells from the pre-IVM follicles were not subjected to any in vitro manipulation, the hypermethylated pattern that was observed may be the actual physiological methylation pattern for this particular locus in these cells. Due the importance of DNA methylation in oogenesis, and to be a non-invasive method for determining oocyte quality, the identification of new epigenetic markers in cumulus cells has great potential to be used to support reproductive biotechniques in humans and other mammals.

Supplementary corpora lutea monitoring allows progestin treatment interruption on day 70 of pregnancy in non-cyclic recipient mares

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Expression of fibroblast growth factor 10 and cognate receptors in the developing bovine ovary

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Prostaglandin treatment at the onset of norgestomet and estradiol-based synchronization protocols did not alter the ovarian follicular dynamics or pregnancy per timed artificial insemination in cyclic Bos indicus heifers

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Progestin-Based Protocol for Synchronization of Follicular Wave Emergence in Buffaloes During Summer and Winter

The aim of the present study was to evaluate the effects of type of norgestomet auricular implant (new - N or previously used during 5 days - U), season of the year (summer - S and winter - W), and parity (12 heifers - H and 23 cows - C) on synchronization of follicular wave emergence in buffaloes. For this purpose, 35 buffaloes were examined daily by ultrasonography until follicular wave emergence was detected. Data were analysed by ANOVA, using PROC GLIMMIX. No interactions were observed in none variables. Time of follicular wave emergence and number of follicles at emergence were not affected by type of implant or season of the year. Parity also did not influence the number of follicles at emergence. However, follicular wave emergence occurred later in heifers than in cows. In conclusion, the previous use of a norgestomet auricular implant independent of the season of the year does not affect the time or the number of follicles at follicular wave emergence in buffaloes. Nevertheless, although heifers and cows had a similar number of follicles at emergence, the time of follicular wave emergence occurs earlier in cows than in heifers.

Influence of Parity and Season of the Year on Oocyte Quality and Number in Buffaloes

The aim of the present study was to evaluate the effects of season of the year (summer and winter) and parity (heifers and cows) on oocyte quality and number in buffaloes. For this purpose, 71 buffaloes had follicular wave emergence synchronized before OPU. OPU of all follicles >= 2mm was done 5 days after the beginning of the hormonal protocol, in 4 replicates (two for each season). Data were analyzed by ANOVA using PROC GLIMMIX, in a 2 x 2 factorial arrangement of treatments. No interactions were observed in following variables: number of follicles, number of total and viable oocytes, recovery rate, percentage of viable oocytes, grade I oocytes, grade II oocytes, grade III oocytes, denuded oocytes, expanded cumulus oocytes, and atretic/degenerated oocytes. Number of follicles visualized at OPU and recovery rate were not affected by parity or season. Relative to parity, number of total and viable oocytes were greater in heifers than in cows, respectively. Concerning season of the year, number of viable oocytes and viable oocyte rate were increased in winter. In conclusion, better oocyte quality can be obtained from heifers and during winter in buffaloes. However, the number of total oocytes seems to be more influenced by parity than by season of the year in this species.

Correlations between ovarian follicular blood flow and superovulatory responses in ewes

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)