Dárcio Ítalo Alves Teixeira

Embryo recovery rate in Santa Inês ewes subjected to successive superovulatory treatments with pFSH

The effect of two successive superovulatory treatments was assessed in 15 Santa Inewes synchronized with 60 mg medroxyprogesterone acetate sponges for 14 days and superovulated with 200 IU of porcine FSH (pFSH) in decreasing doses at 12 h intervals during days 12-14 of progestagen treatment. Estrus was observed from 12 h after sponge removal and the ewes in estrus were hand mated with Santa Inrams of proven fertility. All embryos were recovered by laparotomy 6-7 days after estrus. Treated ewes showed estrus from 24 to 72 h after sponge removal. The time of onset of estrus after sponge removal and the length of estrus were not affected ( P> 0.05) by the repetition of treatment. Ewes that failed to superovulate in the first and the second treatment ( P> 0.05) were 27 and 40%, respectively. The mean ovulation rate for those ewes responding to treatment was similar ( P> 0.05) between the first (9 .9 ± 1.1) and the second (11.3 ± 1.9) treatment. There was no significant difference in fertility between the first (53%) and second (40%) treatment. Among those fertilized, viable embryos were detected for 78% in the first treatment and 64% in the second treatment ( P> 0.05). It was concluded that Santa Inewes respond to superovulatory regimes with pFSH and the treatment may be repeated for at least two times.

Assessment of the reproductive parameters, laparoscopic oocyte recovery and the first embryos produced in vitro from endangered Canindé goats (Capra hircus)

The Canindé breed of goats (Capra hircus) is currently endangered. The aims of this study were to characterize the estrus behavior, ovulatory responses and progesterone profiles, and to evaluate the in vitro embryo production (IVP) in this breed. In Experiment 1, ten nulliparous and seven pluriparous females received medroxyprogesterone acetate (MAP)-containing sponges (60mg) plus 75μg d-cloprostenol for estrus synchronization and their reproductive parameters were evaluated. In Experiment 2, oocytes obtained by laparascopy from hormonally stimulated females (n=15) were used for IVP. There was no difference (p>0.05) between nulliparous and pluriparous goats in terms of estrus response (40.0% vs. 85.7%), time from progestagen sponge removal to the onset of estrus (62.0±15.5 vs. 50.7±19.2h; mean±SEM), duration of estrus (25.0±16.1 vs. 30.0±15.1h), percentage of ovulating animals (60.0% vs. 85.7%), number of ovulations (1.2±0.4 vs. 1.3±0.8), and diameter of the preovulatory follicle (5.8±0.5 vs. 6.1±0.3mm). Progesterone concentrations were also similar (p>0.05) in both groups. During laparoscopic recovery, there were average 12.2 aspirated follicles and 9.1 oocytes per goat, resulting in a high recovery rate (74.3%, 182/245). A total of 78 embryos were produced (51.0%). The mean number of cells in the blastocysts at day 7 of in vitro culture was 170.3±12.5. In conclusion, nulliparous and pluriparous Canindé goats exhibited similar reproductive profiles. It was possible to produce embryos in vitro, allowing the instigation of an embryo bank for preservation of this breed.

Ovarian follicular response to different hormonal stimulation treatments in Canindé goats

The objective of the present study was to evaluate the effect of different hormonal stimulation treatments on the antral follicular population of naturalized Canindé goats. Adult goats (n=17) having estrous cycles at regular intervals were treated with intra-vaginal sponges containing 60 mg medroxyprogesterone acetate for 11 days, combined with an application of 50 μg d-cloprostenol on the Day 8 of treatment. For ovarian stimulation, goats were distributed into the following experimental groups: (a) multiple doses (MD), with a total of 120 mg NIH-FSH P1 in five intramuscular injections (30/30; 20/20 and 20 mg) at 12-h intervals; (b) three doses (TD), with a total of 120 mg NIH-FSH P1 in three intramuscular injections (60; 40 and 20 mg) at 24 h intervals; (c) one dose (OD), which consisted of the use of 70 mg NIH-FSH P1 combined with 200 IU eCG administered intramuscularly 36 h before sponge removal. In the MD and TD groups, FSH injections were begun on the Day 8 of progestagen treatment. The ovaries of all animals were observed by transrectal real time ultrasonography (TRU) during the follicular stimulation protocols. All follicles ≥2 mm were counted, measured and classified according to greatest diameter. The ultrasonographic assessment of the ovaries provided for well-defined ovarian structures. At the time of insertion of the sponges (Day 0), significant differences were observed (P<0.05) for the mean number of large follicles between the treated groups. Meanwhile, on Day 11, the three treatments did not differ (P<0.05), regardless of the follicular category. The diameter of small follicles was similar in MD, TD and OD during the whole period of the study. In the TD group, diameter of the large follicles was less (P<0.05) on Day 10 when compared to MD and OD. However, these differences were not observed on Day 11. In conclusion, the three treatments produced comparable distribution of the follicular populations. However, the single dose treatment can be preferred because of its simplicity and efficacious follicular response.

Quantitative expression analysis of Bodhesin genes in the buck (Capra hircus) reproductive tract by real-time polymerase chain reaction (qRT-PCR)

Knowledge of the different patterns of gene expression along the male reproductive tract can assist in understanding the physiological processes of species-specific reproduction in mammals. In the present work, expression profiles of buck spermadhesin (bodhesin) genes along the reproductive tract by qRT-PCR were investigated. Total RNA from the seminal vesicle, testis, epididymis, bulbourethral gland and ductus deferens were reverse transcribed and the cDNA produced was submitted to qRT-PCR. For each homologous bodhesin gene, namely Bdh-1, Bdh-2 and Bdh-3, sets of specific primers and recombinant plasmids were prepared for gene quantification. In buck seminal vesicles, Bdh-2 is the homologue predominantly expressed, with a copy number on the order of millions of times more than Bdh-1 and thousand times more than Bdh-3. The copy number of Bdh-3 mRNA is only 10-fold greater than that of Bdh-1. Bodhesin transcripts were detected in all tissues examined, except in ductus deferens. The quantitative analysis also demonstrated clearly the differential gene expression of spermadhesin in bulbourethral gland. The striking differences in bodhesin gene expression indicate that each isoform could have a specific biological function in the buck genital tract, which deserves further detailed studies.

Pseudopregnancy in Saanen goats (Capra hircus) raised in Northeast Brazil.

The prevalence of pseudopregnancy over 44 months was investigated in 23 Saanen goats raised in Northeast Brazil during continuous oestrous cycling (cyclic group) or after synchronization of oestrus (synchronized group). The goats were monitored by ultrasonography and their plasma progesterone profile. The overall prevalence of pseudopregnancy was 30.4% (7/23). In the cyclic group, 28.6% (4/14) of goats showed pseudopregnancy, while in the synchronized group the prevalence was 33.3% (3/9). There was no significant difference between the groups (p>0.05). The mean (±SD) length of pseudopregnancy, as shown by the progesterone profile, was 121.6±33.5 days, ranging from 70 to 155 days. The study defined the prevalence of pseudopregnancy in Saanen goats raised in Northeast Brazil for the first time. This finding identified a major problem for this breed, as without treatment such animals remain unproductive until the spontaneous resolution of the condition. More research seems desirable to ascertain the prevalence of this condition in other breeds in this region of Brazil.

Mensurações ultrassonográficas da cisterna da glândula mamária de caprino transgênico

Milk production of transgenic does was evaluated by ultrasound measurements of the mammary gland. Two Caninde goats, which were nine months of age were used in the trial, one non-transgenic or other transgenic for hG-CSF. For hormone-induced lactation, animals were given estradiol (0.25mg/kg, IM), progesterone (0.75mg/kg, IM), and prednisolone (0.4mg/kg, IM). Ultrasonographic exams were carried out during milking, using a Falcon 100 ultrasound equipment with a 5MHz convex probe and were performed by the same operator. The results were expressed as mean±standard error. The maximum greater length and shorter length of the cistern were respectively 5.14cm and 1.36cm for the transgenic animal and 7.28cm and 2.25cm for non-transgenic, which is consistent with the maximum milk volume produced. The relationship between the average area of cisterns and milk yield was expressed as a linear correlation curve, with a correlation coefficient significantly positive for both transgenic (Y=-1.1314+10.8538*x; r=0.97) and non-transgenic (Y=-21.7551+18.3634*x; r=0.97) animals. In conclusion, the ultrasound is a practice and appropriate technique to evaluate the cisterns in ruminant udders in transgenic animal.

Effect of crotamine, a cell-penetrating peptide, on blastocyst production and gene expression of in vitro fertilized bovine embryos.

The present study investigated the effects of crotamine, a cell-penetrating peptide from rattlesnake venom, at different exposure times and concentrations, on both developmental competence and gene expression (ATP1A1, AQP3, GLUT1 and GLUT3) of in vitro fertilized (IVF) bovine embryos. In Experiment 1, presumptive zygotes were exposed to 0.1 μM crotamine for 6, 12 or 24 h and control groups (vehicle and IVF) were included. In Experiment 2, presumptive zygotes were exposed to 0 (vehicle), 0.1, 1 and 10 μM crotamine for 24 h. Additionally, to visualize crotamine uptake, embryos were exposed to rhodamine B-labelled crotamine and subjected to confocal microscopy. In Experiment 1, no difference (P > 0.05) was observed among different exposure times and control groups for cleavage and blastocyst rates and total cells number per blastocyst. Within each exposure time, mRNA levels were similar (P > 0.05) in embryos cultured with or without crotamine. In Experiment 2, concentrations as high as 10 μM crotamine did not affect (P > 0.05) the blastocyst rate. Crotamine at 0.1 and 10 μM did not alter mRNA levels when compared with the control (P > 0.05). Remarkably, only 1 μM crotamine decreased both ATP1A1 and AQP3 expression levels relative to the control group (P < 0.05). Also, it was possible to visualize the intracellular localization of crotamine. These results indicate that crotamine can translocate intact IVF bovine embryos and its application in the culture medium is possible at concentrations from 0.1-10 μM for 6-24 h.

Methodological strategies for transgene copy number quantification in goats (Capra hircus) using real‐time PCR

Taking into account the importance of goats as transgenic models, as well as the rarity of copy number (CN) studies in farm animals, the present work aimed to evaluate methodological strategies for accurate and precise transgene CN quantification in goats using quantitative polymerase chain reaction (qPCR). Mouse and goat lines transgenic for human granulocyte‐colony stimulating factor were used. After selecting the best genomic DNA extraction method to be applied in mouse and goat samples, intra‐assay variations, accuracy and precision of CN quantifications were assessed. The optimized conditions were submitted to mathematical strategies and used to quantify CN in goat lines. The findings were as follows: validation of qPCR conditions is required, and amplification efficiency is the most important. Absolute and relative quantifications are able to produce similar results. For normalized absolute quantification, the same plasmid fragment used to generate goat lines must be mixed with wild‐type goat genomic DNA, allowing the choice of an endogenous reference gene for data normalization. For relative quantifications, a resin‐based genomic DNA extraction method is strongly recommended when using mouse tail tips as calibrators to avoid tissue‐specific inhibitors. Efficient qPCR amplifications (≥95%) allow reliable CN measurements with SYBR technology. TaqMan must be used with caution in goats if the nucleotide sequence of the endogenous reference gene is not yet well understood. Adhering to these general guidelines can result in more exact CN determination in goats. Even when working under nonoptimal circumstances, if assays are performed that respect the minimum qPCR requirements, good estimations of transgene CN can be achieved.

Hormonal treatments for the synchronisation of oestrus in dairy goats raised in the tropics

In tropical areas, local goats are often reported as being able to reproduce throughout the year, whereas an influence of season is found to be a factor when importing different dairy breeds. In these areas, oestrus synchronisation in goats is of interest for both technical (synchronisation of kidding, adjustment to forage availability or to continuous milk supply) and genetic reasons (dissemination of improved genotypes by AI). The use of a progestagen vaginal sponge combined with equine chorionic gonadotrophin (eCG)-cloprostenol injections remains an efficient tool to achieve synchronisation in temperate and tropical zones. However, the oestrus synchronisation treatments currently used for goats in tropical regions were originally developed for goats bred in temperate regions. For this reason, several alternative possibilities for improving the efficiency of the hormonal treatment are evaluated. Oestrus synchronisation with luteolytic agents is efficient (resulting in more than 70% of goats in oestrus) and it takes into account female cyclicity. In developing regions of the tropics, the use of buck teasing appears to be a promising approach to control oestrus and ovulation. The use of this technique provides 60% of females in oestrus within 5 days of introducing the bucks. Considering the availability of nutrients as the ultimate regulator of reproduction in the tropics, the control of nutritional condition is essential before the use of hormonal treatments for oestrus synchronisation in goats bred in these regions takes place.

Effect of age of donor on embryo production in Morada Nova (white variety) ewes participating in a conservation programme in Brazil

In order to evaluate embryo production in Morada Nova (white variety) ewes superovulated with porcine follicle-stimulating hormone, 20 cycling ewes were used as embryo donors and allocated into two groups according to age: group 1 (ewes aged 1–2 years; n = 9) or group 2 (ewes aged 3–4 years; n = 11). Embryo recovery was performed by laparotomy 5–6 days after oestrus. The evaluation of embryos was made under stereomicroscope according to International Embryo Transfer Society rules. The overall recovery rate was 64.6% (5.0 ±  0.7 structures per ewe) and 86.3% of the recovered structures were fertilized. Group 1 was superior (p < 0.05) to group 2 according to recovered (6.6 ±  0.9 vs 3.6 ±  0.8) and fertilized structures (5.6 ±  1.1 vs. 3.5 ±  0.7) per ewe. In conclusion, the ovarian response and the embryo production in Morada Nova (white variety) sheep subjected to a standard superovulation treatment were considered satisfactory. In addition, the use of multiple ovulation and embryo transfer in younger ewes (≤ 2 years old) of this sheep breed appears to be an efficient tool to accelerate the preservation of the Morada Nova (white variety) breed, since younger ewes are as responsive as older ones.