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.

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® (BB)

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RESUMO:O objetivo do estudo foi checar a eficiência reprodutiva da eCG e do desmame temporário em protocolos para IATF em vacas Nelore pluríparas, previamente tratadas com progesterona intravaginal e benzoato de estradiol (BE). Foram utilizadas 343 animais, com ECC médio de 2,65 (1=magra; 5= gorda), no período pós parto (media 51,9 dias), e divididas em dois grupos(G): GeCG (grupo gonadotrofina coriônica equina; n=144) recebeu no dia 0 (d0) 0,558 g de P4 + 1,0 mg de BE; em d8 (remoção da P4 + 0,075 mg de PGF2 alfa+1,5 mg de cipionato de estradiol-ECP + 400UI de eCG); em d10 execução da IATF; o GDT (grupo desmame temporário; n=199) o mesmo que GeCG sem eCG no d8, e com desmame temporário por 48 horas e retorno dos bezerros às mães no dia da IATF(d10). A taxa de prenhes (TP) à IATF, após 35 dias resultou em 59,0 e 63,3 % respectivamente para os GeCG e GDT (P>0,05) e a TP à IATF + o repasse com touros, em 90,9 e 95,9 % (P=0,056), após 90 dias de estação de monta. Concluiuse que ambos os protocolos mostraram-se eficientes em fazendas comerciais de bovinos de corte, enfatizando-se a utilização do DT onde haja facilidade de manejo.

The widespread occurrence of anthelmintic-resistant gastrointestinal nematodes (GINs), particularly Haemonchus contortus, in sheep production systems has magnified the need to identify and develop alternative control strategies. Strategies include the selection of genetically GIN-resistant sheep and the implementation of biological parasite control to reduce dependence on anthelmintic drugs. In this study, we aimed to establish the molecular identity of bacterial communities present in the abomasum of sheep classified as resistant or susceptible to H. contortus. Thirty-eight sheep were experimentally infected with L3 Haemonchus contortus and analyzed for fecal egg count (FEC), and hematocrit (Ht) to establish haemonchosis resistance or susceptibility. Four resistant sheep (RS) and four susceptible sheep (SS) were selected for microbial sampling and subsequent phylogenetic analysis. Molecular identification of the bacteria was based on amplification of the bacterial 16S rRNA gene, construction of a 16S rDNA clone library, and subsequent gene sequencing. Significant differences (p = 0.05) were observed in the occurrence of different phyla identified in RS and SS libraries: Firmicutes (61.4% and 37.2%, respectively), Proteobacteria (10.2% and 37.2%, respectively), Bacteroidetes (12.8% and 5.8%, respectively), and unclassified bacteria (12.8% and 17%, respectively). Differences between the proportions of bacterial communities present in the RS and SS pool samples were observed, contributing as a first step toward the assessment of the association between the gastrointestinal tract microbiota and nematode resistance in sheep. ResumoNa produção de ovinos, a disseminação de nematódeos gastrintestinais (NGI) resistentes aos antihelmínticos, em especial Haemonchus contortus, tem levado à busca de estratégias de controle alternativo, como a seleção de animais geneticamente resistentes aos NGI e o controle biológico. Neste trabalho, buscou-se identificar molecularmente as comunidades bacterianas presentes no abomaso de animais classificados como resistentes ou susceptíveis ao H. contortus. Foram utilizados 38 ovinos para classificação em resistentes ou susceptíveis à hemoncose, por meio de infecções experimentais com L3 de H. contortus e posterior análise de variações na contagem de ovos por grama de fezes (∆OPG) e hematócrito (∆Ht). Destes, foram selecionados para colheita de material e posterior análise filogenética, quatro ovinos resistentes (OR) e quatro susceptíveis (OS). A identificação molecular de bactérias foi realizada por técnicas moleculares a partir da amplificação do gene RNAr 16S bacteriano, construção de bibliotecas de clones de RNAr 16S e posterior sequenciamento gênico. O trabalho mostrou diferença significativa (p=0,05) na porcentagem dos filos predominantes para as bibliotecas OR e OS, respectivamente: Firmicutes (61,4% e 37,2%), Proteobacterias (10,2% e 37,2%), Bacteroidetes (12,8% e 5,8%) e Bactérias não classificadas (12,8% e 17%). Diferenças entre os pools OR e OS com relação à proporção de...