Influência de diferentes sistemas e curvas de congelamento na congelabilidade e fertilidade do sêmen equino / Influence of systems and freezing curve in equine semen freezability and fertility

Avaliou-se o efeito de curvas de congelação nos parâmetros espermáticos e na fertilidade, usando sêmen de alta e baixa congelabilidade. Experimento 1 - utilizou-se sêmen de quatro garanhões resistentes à congelação: grupo 1, palhetas refrigeradas até 5°C e congeladas com curva de -8°C/min; grupos 2 e 3, palhetas refrigeradas até 5°C (0,5°C/min.) e congeladas com curvas de -20°C/min e -10°C/min, respectivamente. Experimentos 2 e 3 - utilizaram-se cinco garanhões (Mangalarga Marchador), respectivamente, de alta e baixa congelabilidade: grupo 4, a mesma metodologia descrita no grupo 1; grupos 5 e 6, palhetas refrigeradas até 5°C (0,5°C/min) e congeladas com curva de -20°C/min, entre 5°C e -60°C, e -10°C/min, entre -60°C e -100ºC (grupo 5), e -25°C/min, de 5°C até -100°C (grupo 6). O sêmen foi avaliado após descongelamento pelo método computadorizado. No experimento 1, não houve diferença nos parâmetros avaliados. No experimento 2, os parâmetros motilidade total (MT) e motilidade progressiva foram superiores aos do grupo 6 em relação ao grupo 4. No experimento 3, a MT foi superior no grupo 6 em relação ao grupo 4. As curvas de congelação mais rápidas apresentaram melhores parâmetros de cinética espermática, após a descongelação, para o sêmen de garanhões da raça Mangalarga Marchador.(AU)

The effect of freezing curves on sperm parameters and fertility, using resistant and sensitive semen to cryopreservation, was evaluated. In experiment 1, Semen from 4 stallions resistant to freezing was used: Group 1, straws were cooled to 5°C and frozen with a curve of - 8°C/min; Groups 2 and 3, straws were cooled to 5°C (0.5°C/min) and frozen with curves of - 20°C / min and - 10°C/min, respectively. In experiments 2 and 3, 5 stallions (Mangalarga Marchador) presenting respectively resistant and sensitive sperm to cryopreservation were used: Group 4, same methodology described for Group 1 was performed; Groups 5 and 6, straws were cooled to 5°C (0.5°C/min) and frozen with a curve of - 20°C/min. between 5°C and - 60°C and -10°C/min. between - 60°C and - 100°C (Group 5) and - 25°C/min. 5°C to - 100°C (Group 6). Thawed-semen was evaluated by the computerized method CASA. In Experiment 1, there was no difference in the evaluated parameters. In Experiment 2, total motility (MT) and progressive motility (PM) were higher in Group 6 compared to Group 4. In Experiment 3, TM was higher in Group 6 than Group 4. The faster freezing curves showed better parameters of sperm kinetics after thawing, for the Mangalarga Marchador stallion semen.(AU)

Pentoxifylline effects on capacitation and fertility of stallion epididymal sperm.

The aims of this study were to determinate whether pentoxifylline (PTX) increases the motion parameters of fresh and frozen-thawed equine epididymal spermatozoa, to evaluate the tyrosine phosphorylation of frozen-thawed epididymal sperm in the presence of PTX and to determine whether the PTX-treatment of stallion epididymal sperm prior to freezing improves the fertility response of mares to a reduced number of spermatozoa per insemination dose. Fifty epididymis were flushed with a skim milk based extender with or without PTX. The pre-treatment with PTX enhanced the sperm motility after being harvested (P<0.05); however the freeze-thaw process did not alter the sperm kinematics between control and treated samples (P>0.05). Plasma membrane integrity did not differ between control and PTX group after recovery and after thawing (P>0.05), as observed in tyrosine phosphorylation, which the PTX treatment did not alter the percentage of tail-associated immunofluorescence of cryopreserved epididymal sperm (P>0.05). For the fertility trial, different insemination groups were tested: 800×106 epididymal sperm (C800); 100×106 epididymal sperm (C100); 100×106 epididymal sperm recovered in an extender containing PTX (PTX100). The conception rates for C800; C100 and PTX100 were 68.7% (11/16); 31.5% (5/16) and 50% (8/16), respectively. The conception rate did not differ among groups (P>0.05), however, a low number of animals was used in this study. A trend toward significance (P=0.07) was observed between C800 and C100 groups. In conclusion, PTX has no deleterious effect on sperm motility, viability and capacitation of cryopreserved stallion epididymal sperm. The conventional artificial insemination with 100×106 sperm recovered with PTX ensures acceptable conception rates and maximize the limited number of doses of cryopreserved stallion epididymal sperm.

Determination of equine fetal sex by Doppler ultrasonography of the gonads.

REASONS FOR PERFORMING THE STUDY: The identification of fetal sex in horses by location of the genital tubercle between 55 and 70 days of pregnancy is hampered by the large amount of allantoic fluid, extensive fetal movements and the extremely long umbilical cord; however, reliable results have been achieved by ultrasonographic evaluation of the fetal gonads at 110-150 days of pregnancy. OBJECTIVES: The aim of this study was to diagnose the sex of equine fetuses using B-mode and/or colour Doppler transrectal ultrasonography in fetuses of different ages. STUDY DESIGN: Cross-sectional study comparing 2 methods of determining fetal sex. METHODS: The evaluations were performed in 86 mares at 90-180 days of pregnancy using transrectal B-mode and colour Doppler mode ultrasonography. Fetuses that had gonads with a homogeneous texture and a thin central longitudinal echogenic line were considered to be male. Females were identified by the presence of gonads with a central circular echogenic structure surrounded by a hypoechogenic external halo. RESULTS: Using B-mode ultrasonography, it was possible to determine the sex of 75% of the males, while determination of sex based on differences between the medullary and cortical layers of the ovary allowed 91.1% of females to be correctly identified. Using Doppler ultrasonography, 100% of males were successfully identified, while characteristic vascularisation of the female gonad could be detected in 98% of the evaluated female fetuses. CONCLUSIONS: Colour Doppler ultrasonography combined with B-mode ultrasonography allows the determination of fetal sex with greater accuracy than B-mode ultrasonography alone, particularly for the identification of the male gonad. The use of Doppler ultrasonography enables the identification of sex in older fetuses.

Novos contornos da gestão local: conceitos em construção / New profile of local management: concepts in construction

Busca apoiar o processo de reflexão a partir da busca de conceitos provisórios. Cada capítulo é resultado de uma questão que se identifica estar no presente no atual debate sobre o espaço de inovação local, incluindo a própria possibilidade de desenvolvimento local. Lança o desafio da construção de um marco conceitual inicial, a partir da reflexão sobre as lições da prática. Entende que a construção de idéias requer a diversidade e a divergência, especialmente quando estas têm impacto na prática democrática. (AU)

Consórcios intermunicipais: uma alternativa de integração regional ascendente / Inter-municipal consortia: a alternative of regional integration

Trata basicamente dos consórcios intermunicipais, vistos como instrumentos de cooperação entre governos municipais localizados em uma determinada microrregião ou região. Conceitua os consórcios. apresenta a base constitucional e legal existente nas áreas de saúde, assistência social e recursos hídricos. Identifica os pressupostos e etapas para constituição dos consórcios. apresenta como é normalmente a sua estruturação hierárquica e gerencial, seu financiamento e seus recursos humanos. Delineia diferenças entre os consórcios e outras formas de cooperação intermunicipal que têm aparecido desde a década de 1990. Apresenta uma análise sintética das experiências de cooperação entre municípios brasileiros, existentes nas bases de dados consultadas. Apresenta considerações para o debate. (AU)