Impact of a progesterone-releasing intravaginal device and inflammatory reaction on ovarian activity in embryo-recipient anestrus mares.

This study aimed to correlate the inflammatory reaction (IR) caused by a progesterone-releasing intravaginal device (P4) with ovarian activity and pregnancy rate (PR) in embryo-recipient anestrus mares (to decrease the spring transitional period). 50 animals were assigned to three groups: GP4 (P4 group; n = 16), GP4OH (P4 + oxytetracycline hydrochloride and hydrocortisone sprayed onto the device; n = 14), and GNP4 (no intravaginal P4; n = 20). The administration protocol for GP4 was: Day 0, 750 mg P4 + ovarian examination by ultrasonography (US) + vaginal sample collection; Day 8, US; Day 11, P4 removal + 7.5 mg PGF2α + US + second vaginal sample collection; Days 13 to 16, US; Days 17 to 21, US + 750 IU hCG to mares with follicles 35 mm or more in diameter; Days 19 to 23 US (ovulation check); Days 24 to 28, embryo transfer + intravenous flunixin meglumine; and Days 30, US pregnancy diagnosis. The GP4OH and GNP4 mares received the same administration protocol as GP4, except that no P4 device was administered to the GNP4 group on Day 0. Although neutrophil-mediated IR occurred in the GP4 and GP4OH groups, the IR was significantly reduced in GP4OH as compared with that in GP4 (P < 0.0001). From Day 0 to Day 17, the GP4 and GP4OH mares developed a greater number of follicles per animal than did the GNP4 mares (P < 0.05), and the average diameter of the follicles was larger in the GP4 and GP4OH mares. The ovulation rates in GP4, GP4OH, and GNP4 mares were, respectively, 43.7%, 64.3%, and 30.0%, and ovulation occurred at 6.8, 6.5, and 23 days after P4 removal (P < 0.05). On Day 17, endometrial edema was verified in 50%, 64.2%, and 35.0% of the GP4, GP4OH, and GNP4 mares, and the PRs after embryo transfer were 80%, 100%, and 66.6%, respectively. Although intravaginal devices caused IR in both the device-recipient groups (P = 0.0001), IR and vaginitis had no negative impact on follicle diameter, ovulation rate, period to ovulation after the removal of P4, endometrial edema, or PR. In addition, P4 reactivated the ovarian function and the IR eliminated a large percentage of bacteria (Bacillus spp., Enterobacter spp., Proteus spp., Pseudomonas spp., and Staphylococcus spp.), especially in GP4; the application of oxytetracycline hydrochloride and hydrocortisone on the devices reduced the severity of vaginitis.

In vitro and in vivo fertilization potential of cryopreserved spermatozoa from bull epididymides stored for up to 30 hours at ambient temperature (18 °C-20 °C).

The aims of this study were to compare the viability and in vivo and in vitro fertilization potential post-thaw sperm collected at different times postorchiectomy from bull epididymides (EP) at 18 °C to 20 °C, with those of semen collected by electroejaculation (EJ) from the same bulls. Semen samples were collected by EJ from 10 Zebu bulls and cryopreserved. A week later 20 epididymides from these bulls were obtained by orchiectomy and randomly divided into five groups (G) to be maintained at ambient temperature for 6, 12, 18, 24, and 30 hours before sperm recovery by retrograde flow. The sperm were cryopreserved, and post-thaw parameters were determined by both computer-assisted sperm analysis and morphologic analysis. In vitro fertilization of oocytes was performed to assess the cleavage rate, blastocyst rate, total number of cells, and hatching rate of embryos. The G30 sperm samples were also used for fixed time artificial insemination (FTAI) of Zebu heifers (n = 10). The results of post-thaw sperm viability showed that total and progressive motility and plasma membrane integrity were lower in sperm in which cryopreservation was delayed for 30 hours, showing a negative correlation of these parameters with delay before cryopreservation. In all groups, it was possible to obtain viable embryos, and embryos from G6 samples had more cells than the other groups. The greatest embryo production rates were observed in G6, G12 and G18 (27.2 to 32.2%) and it was significantly lower in G24 and G30 samples. For EJ, many individual variations were observed in embryo production potential between bulls. G30 samples, with only 5.2% of post-thaw progressive motility, were able to fertilize and produced a pregnancy. To the authors' knowledge, this is the first time in vitro embryos up to 8 days of development and a pregnancy after FTAI have been produced with sperm from bull epididymides that had been stored at 18 °C to 20 °C for up to 30 hours.

Dois diluentes comerciais na criopreservação de espermatozoides do epidídimo de touros / Two commercial extenders for cryopreservation of epididymal bull sperm

A recuperação e a criopreservação de espermatozoides do epidídimo constituem alternativas viáveis para a preservação de material genético de animais valiosos. O objetivo deste estudo foi comparar o desempenho de dois diluentes comerciais Botu-Bov(r) (BB) e Bovimix(r) (BV), sobre a viabilidade pós-descongelação de espermatozoides do epidídimo de touros Tabapuã (Bos taurus indicus) pós-castração. Os espermatozoides foram colhidos da cauda de 20 epidídimos utilizando a técnica de fluxo retrógrado, centrifugados e diluídos com BB ou BV para posterior criopreservação a -196°C. Após a descongelação, as amostras foram avaliadas utilizando a análise computadorizada (CASA) e por análises microscópicas para a determinação da integridade de membranas plasmáticas, acrossomal e morfologia espermática. A avaliação estatística dos dados foi realizada pela análise de variância (ANOVA) com o pós-teste de comparações múltiplas de Tukey-Kramer, com nível de significância (P<0,05). Os resultados do movimento espermático avaliado pelo CASA, não diferiram para o diluente BB e BV. Também não foi observada diferença significativa entre os grupos no percentual de espermatozoides morfologicamente deformados, defeitos de acrossoma e espermatozoides com membrana plasmática íntegra após o descongelamento. Conclui-se que ambos os diluentes (BB e BV) são eficientes e podem ser utilizados na tecnologia do congelamento de espermatozoides colhidos da cauda do epidídimo de touros, não apresentando diferença na viabilidade espermática para os parâmetros estudados.

Recovery and cryopreservation of epididymal sperm is a viable alternative for preservation of genetically valuable animals. The aim of this study was to verify and to compare the effect of two commercial extenders for conventional semen on post-thawing viability of bovine epididymal sperm. For this purpose, the spermatozoa was recovered from the tail of 20 epididymis of Tabapuã bulls (Bos Taurus indicus) using retrograde flow method. After sperm recovery, the cells were centrifuged and divided for dilution with the diluents Botu-Bov(r) (BB) or Bovimix(r) (BV) for cryopreservation at -196°C. After thawing, all samples were evaluated using computer assisted sperm analysis (CASA), and by microscopic analysis for determination of integrity of plasma and acrossomal membrane and morphology. Statistical evaluation was performed by analysis of variance (ANOVA) with post-test for multiple comparisons, the Tukey-Kramer test, with significance level (P<0.05). The results of the sperm movement for diluent BB and BV evaluated with CASA, showed no difference for both (P>0.05). There was also no difference between the percentage of deformed sperm, acrosome defects and the sperm with intact plasma membrane after thawing with BB or BV. We conclude that both extenders (BB and BV) are efficient and can be used for freezing sperm collected from the epididymis of bulls, showing no difference for all the parameters studied.

Viability of bull spermatozoa collected from the epididymis stored at 18-20°C

The aim of this study was to evaluate the viability of bull spermatozoa collected from the cauda epididymis stored at 18-20°C, which were compared with semen collected by electro-ejaculation method and preserved at 5°C. Ten pairs of testes from Tabapuã bulls were removed by orchiectomy and stored for 6 (G6), 12 (G12), 18 (G18), 24 (G24) and 30 (G30) h at room temperature (18-20°C). Seven days before orchiectomy, semen was collected by electro-ejaculation method. The sperm parameters evaluated were: sperm motility, vigor, concentration, morphology and acrosome defects. Sperm motility declined (p<0.05) when spermatozoa were stored for 30 h in the epididymis. The spermatozoa from the epididymis showed lower sperm motility than that of spermatozoa collected via electro-ejaculation. There was a little expressive decrease in sperm vigor and increased in morphological defects with storage time, but the acrosome integrity was not affected. Cold storage (5°C) maintained sperm viable for 15 to 40.8 h. Thus, it was possible to recover viable sperm with 41.25% of motility from the cauda epididymis stored at room temperature of 18-20°C for 30 h. There were differences between the ejaculated and epididymal sperm for the bulls and the conservation at 5°C allowed short-term preservation of the gametes.

Parâmetros utilizados na avaliação do metabolismo do ferro em cães / Iron metabolism parameters in dogs

A avaliação do metabolismo de ferro associado aos resultados hematológicos constitui uma ferramenta importante para o diagnóstico, controle e diferenciação de estados anêmicos. O presente trabalho objetivou determinar os parâmetros utilizados na avaliação do metabolismo do ferro (ferro sérico, capacidade latente de ligação do ferro, capacidade total de ligação do ferro, índice de saturação do ferro, transferrina e ferritina) em cães sadios. Foram selecionados 120 cães, divididos em quatro grupos de sexo e faixa etária distintos (30 machos jovens e 30 adultos, 30 fêmeas jovens e 30 adultas). As amostras de sangue foram coletadas das 8h às 11h, com os cães em jejum. Os valores médios para as concentrações de ferro sérico, capacidade latente de ligação do ferro, capacidade total de ligação do ferro, índice de saturação do ferro e transferrina foram 138,2µl dl-1; 371µl dl-1; 232,6µl dl-1; 37,7 por cento e 259,6mg dl-1, respectivamente. Esses índices foram avaliados quanto às variações entre sexo e idade. Os valores médios foram submetidos ao teste de Tukey e não apresentaram variação significativa (P<0,01). A concentração de ferro sérico apresentou-se mais elevada em cães machos adultos, comparados aos machos jovens (P<0,05). O valor de ferritina obtido foi inferior a 1ng mL-1 com reagente comercial de imunoensaio quimioluminescente para humanos.

The determination of iron metabolism rates associated with hematological findings is an important tool to diagnosis, control and differentiation of anemic states. This study has as objective to determine the iron parameters (serum iron, unsaturated iron binding-capacity, total iron binding-capacity, transferrin saturation rate (IST), transferrin and ferritin) in healthy dogs. It was selected 120 dogs, shared in four different groups of sex and age (30 young males and 30 adult males, 30 young females and 30 adult females). The blood samples were collected between 8 and 11h AM, with fasted dogs. The average values to serum iron, unsaturated iron binding-capacity, total iron-binding-capacity, transferring percent saturation and transferrin are 138.2µl dl-1; 371µl dl-1; 232.6µl dl-1; 37.7 percent e 259.6mg dl-1 respectively. These rates were evaluated according to sex and age variation. The average values submitted to Tukey test it were not significant (P<0,01). Considering a 5 percent level variation of error probability, the serum iron was higher in adult male dogs, comparing with young male ones (P<0,05). The ferritin values were 0ng mL-1 in human chemiluminescent immunoassay kit.