a b s t r a c tOne of the main factors known to influence quality and fertility of bovine cryopreserved semen is the extender used. In this matter, a great worldwide interest has been directed to the development of chemically defined media, free of animal origin products. The objective of the present study was to compare the efficacy of three bovine semen extenders: Tris-fructose (TRIS, control with 20% egg yolk), Botu-Bov s (BB; 20% egg yolk), and Botu-Bov s -soy lecithin (BB-L; 1% soy lecithin). Towards this aim, post-thaw computer assisted sperm analysis (CASA), sperm membrane and acrosome integrity were evaluated (Experiment 1). Additionally, cryopreserved samples were used in a fixed time artificial insemination program aiming to evaluate in vivo fertility (pregnancy per insemination-P/AI; Experiment 2). Despite the higher straightness and linearity found for samples cryopreserved in BB and BB-L when compared to those cryopreserved in TRIS, egg yolk based extenders provided higher total and progressive motilities, percentage of rapid sperms and intact membrane cells (P o 0.05). Furthermore, P/IA was higher in samples cryopreserved in egg yolk based extenders when compared to soy lecithin [TRIS ¼ 59.26 a (64/108), BB ¼ 62.37 a (58/93), and BB-L ¼36.45 b (35/96)]. Although soy lecithin represents an alternative for the development of chemically defined extenders with decreased risk of biological contamination, egg yolk based extenders are more efficient on the preservation of bovine post-thaw sperm viability and fertility.

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RESUMOA expressão de receptores de estrógeno (ER) e progesterona (PR) por meio da técnica de q-PCR foi avaliada em 26 cadelas portadoras de neoplasias mamárias e cinco cadelas sem afecções mamárias (grupo controle). Os resultados mostraram que os três grupos de animais estudados -com tumor maligno ou benigno e controle  expressaram receptores de estrógeno alfa, beta e progesterona. A quantificação relativa mostrou tendência para uma expressão maior de receptores no grupo controle e menor no grupo de animais com neoplasias malignas. Além disso, observou-se expressão maior de ERα em relação ao ERβ, e as neoplasias malignas de origem mista apresentaram maiores concentrações dos receptores PR, ERα e ERβ que as neoplasias de origem epitelial.Palavras-chave: cadela, neoplasia mamária, estrógeno, progesterona, receptores Os tumores da glândula mamária de cães têm interesse especial para os pesquisadores que trabalham com neoplasias em razão de algumas similaridades com o câncer de mama humano. Inclusive tem sido proposto, em muitos trabalhos, o estudo dessas lesões na espécie canina como modelo comparativo para a espécie humana (Schneider, 1970;Peleteiro, 1994). As hipóteses etiológicas da neoplasia mamária envolvem a origem viral, influência da dieta e obesidade, componentes genéticos, estresse Recebido em 8 de maio de 2011 Aceito em 20 de julho de 2012 E-mail: renataramos_vet@yahoo.com.br oxidativo e, principalmente, influência hormonal (Peleteiro, 1994; Fonseca e Daleck, 2000;Zuccari et al., 2001;Silva et al., 2004). Nas cadelas, a ovariossalpingohisterectomia realizada antes do primeiro estro reduz o risco de desenvolvimento da neoplasia mamária para 0,5%; esse risco aumenta significativamente nas fêmeas esterilizadas após o primeiro ciclo estral (8,0%) e o segundo (26%). A proteção conferida pela castração desaparece após os dois anos e meio de idade, quando nenhum efeito é obtido (Schneider et al ABSTRACT The estrogen and progesterone receptor (ER and PR) expression with the q-PCR technique was evaluated in 26 female dog carrying of mammary tumors and five female dogs without mammary disease (control group

In the present study, different freezing systems (Styrofoam box and Mini Digitcool ZH 400) and storage volumes (0.5-and 0.25-mL straws) were compared with regard to sperm kinetics and plasma membrane integrity of frozen and thawed semen. For that, three ejaculates from four animals were frozen in Styrofoam box and Mini Digitcool ZH 400 machine. The 0.5-mL straws were thawed at 46 C for 20 seconds, and the 0.25-mL straws were thawed at 46 C for 12 seconds. Statistical analysis was performed using program R of descriptive analysis box plot, followed by analysis of variance using PROC MIXED of SAS 9.1 package. Variances of 5% were considered as different. There was no interaction between the straw sizes and volumes; however, statistical differences were observed between the semen storage volumes. The 0.5-mL straws had higher total motility (%), progressive motility (%), average path velocity (mm/s), straight-line velocity (mm/s), curvilinear velocity (mm/s), and rapid sperm percentage (%) than the 0.25-mL straws. However, plasma membrane integrity analysis did not differ between the two straws. Thus, it is possible to conclude that equine sperm cryopreserved in 0.5-mL straws has better sperm kinetics than when stored in 0.25-mL straws. Additionally, it is possible to conclude that automated systems that enable faster freezing rates result in a seminal quality that is similar to the one obtained by the conventional system using Styrofoam boxes.

SummaryFreezing epididymal sperm is a method to preserve germplasm from animals with not only high genetic potential but also endangered species. In the equine some owners have chosen this possibility in cases of either severe illness or death of stallions. However, the lack of knowledge and poor published results of such technique hampers its propagation. New procedures have allowed some improvement on fertility rates of frozen sperm from the epididymis of stallions. The aim of this study is to report the advances on processing and cryopreservation of samples from the stallion's epididymal semen.