Treatment with eCG and hCG to induce onset of estrous cycles in ewes during the non-breeding season: Effects on follicular development and fertility.

Although combining of eCG and hCG administrations is known to enhance LH-like actions, there have been few studies where there was comparison of the effects of treatment of anestrous ewes with eCG and hCG and eCG alone. In Experiment 1, 18 ewes in seasonal anestrus were administered an intravaginal device (IVD) containing medroxyprogesterone acetate for 12 days, and at the time of IVD removal (D0), were allocated into the following groups (n = 6/group): no further treatment (control); 400 IU eCG (eCG); or 400 IU eCG and 200 IU hCG (eCG + hCG). There was greater ovarian follicular growth in the groups treated with gonadotropins, compared to the control, and there were greater progesterone concentrations in the eCG + hCG group on D9 (P < 0.05). In Experiment 2, 66 ewe lambs were assigned to the same treatment groups described for Experiment 1, and subsequently there was natural mating with rams. There was a greater rate of behavioral estrous manifestation in the eCG (88.5 %; 23/26) and eCG+hCG (85.2 %; 23/27), than control (30.8 %; 4/13; P < 0.05) group. Pregnancy rate was also greater in the eCG (34.6 %; 9/26) and eCG+hCG (18.6 %; 5/27) than control (0 %; 0/13; P < 0.05) group, whereas conception rate, considering only ewe lambs that were mated, was only greater in the eCG group. Although there were greater progesterone concentrations 9 days after treatment in the eCG+hCG group, there was no difference in follicular growth in anestrous ewes, nor was there an effect on estrous behavior manifestation and pregnancy rates in ewe lambs, compared to treatment with only eCG.

The effects of xanthan gum on equine sperm quality during cooling storage / Efeitos de xantam gum em qualidade de esperma equino durante armazenamento resfriado

This study was designed to evaluate the possible benefits of adding xanthan gum to a standard extender for equine through in vitro analyzes of sperm quality. Semen was collected four times from five different stallions (n= 20 samples) and subjected to cooled storage under different conditions: control (only standard extender) and three different concentrations of xanthan gum (0.01%, 0.12%, and 0.25%) supplemented to the extenders. Sperm parameters, such as motility, mitochondrial functionality, and membrane, acrosome, and DNA integrity were measured after 0h, 24h, 48h, and 72h of sperm storage at 5ºC. Our observations indicated that sperm motility declined with longer cooling period with the 0.25% xanthan gum supplementation group compared with the control group. Other parameters, such as mitochondrial functionality and membrane and acrosome integrity also declined for all treatments during storage; however, no differences were observed between xanthan gum and control groups. DNA integrity did not significantly change during the storage. In conclusion, the addition of xanthan gum to equine semen extender is not harmful to the sperm structure, despite reducing the sperm motility.(AU)

Esse estudo foi desenvolvido para avaliar os possíveis benefícios de acrescentar xanthan gum a um extensor padrão através de analises in vitro de qualidade de esperma. Semen foi coletado quatro vezes de cinco garanhões diferentes (n = 20 amostras) e submetido a armazenamen to resfriado em diferentes condições: controle (apenas extensor padrão) e três diferentes concentrações de xanthan gum (0,01%, 0,12% e 0,25%) suplementado aos extensores. Parâmetros dos espermatozoides, como mobilidade, funcionamento mitocondrial e integridade de membranas, acrossomos e DNA forma medidos após 0h, 24h, 48h e 72h de armazenamento a 5oC. Nossas observações indicaram que motilidade reduziu com armazenamento resfriado prolongado no grupo de 0,25% de suplementação de xanthan gum comparado ao grupo controle. Outros parâmetros, como funcionalidade mitocondrial e integridade de membrana e acrossomos também reduziu em todos os tratamentos durante o armazenamento, no entanto não foram detectadas diferenças significativas entre grupos tratados e grupo controle. Integridade de DNA não mudou significativamente durante armazenamento. Em conclusão, a adição de xanthan gum a extensor de sêmen equino não é danosa à estrutura do espermatozoide apesar de reduzir motilidade.(AU)