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Feeding restriction is a strategy in shrimp farming management that may promote compensatory growth after feeding is re‐established. This study aims to evaluate the effects of two feeding restriction regimens on the compensatory growth and digestive enzymes activity of Litopenaeus vannamei reared in biofloc system. Juvenile shrimp (0.46 ± 0.18 g) were stocked (320 individuals/m3) in 310 L tanks. The experiment comprised two phases: (a) Feeding Restriction (30 days) when shrimp were submitted to three feeding regimes, Control (fed daily), R1F1 (repetitively fasted one day and fed one day) and R2F1 (repetitively fasted 2 days and fed 1 day); and (b) Refeeding (28 days) when shrimp were fed daily. In the restriction phase, shrimp growth and digestive enzyme activities were reduced in R2F1 and R1F1. However, during the refeeding phase, enzyme activities and feed conversion improve significantly in R2F1 and R1F1. Control group attained higher final weight, but its final biomass was similar to R1F1. Litopenaeus vannamei exhibited partial compensatory growth, probably due to improved feed conversion efficiency driven by increased enzyme activity. It is possible to reduce feeding by 50% (R1F1) in biofloc systems for 28 days, without compromising the biomass produced at the end of a 30‐day refeeding period.

RESUMOTestaram-se variantes metodológicas utilizando azul de toluidina (AT), até se estabelecer um protocolo confiável para a avaliação computacional da compactação da cromatina em espermatozoides de galo. Para tal, foram utilizados sêmen de 10 galos com 35 semanas de idade e sêmen de 10 galos com 60 semanas de idade. O melhor método foi o de hidrólise com ácido clorídrico 1N por 10 minutos, coloração em cubeta com AT 0,025%, pH 4,0, por 20 minutos, desidratação em álcool, diafanização em xilol e montagem com bálsamo do Canadá. Todas as amostras de sêmen foram submetidas a este protocolo e posteriormente avaliadas por análise de imagem computacional, em que foram feitas mensurações da área, comprimento, largura, perímetro, homogeneidade da compactação da cromatina dentro de cada cabeça e intensidade de compactação da cromatina. Os espermatozoides de galos velhos apresentaram mais alterações na cromatina que os de galos jovens. Os galos jovens apresentaram cabeça dos espermatozoides maior que os galos mais velhos. A análise computacional da compactação da cromatina mostrou-se um método menos subjetivo e mais preciso que a avaliação visual das cabeças dos espermatozoides.Palavras-chave: galo, azul de toluidina, condensação de DNA, fertilidade, análise de imagem, morfometria ABSTRACT The methodological variants using toluidina blue (AT) to establish a trustworthy protocol for the

The work described here aimed to verify the efficiency of different extenders for cryopreservation of equine semen using sperm motility and acrosin activity as spermatic parameters. The semen was fractioned into two equal parts and resuspended in an 11% lactose solution in a 1:1 proportion, where it remained for 20 minutes at room temperature. The semen was centrifuged at 600 g for 10 minutes, and after the second centrifugation, each pellet received the freezing extender (Merck or Zorlesco) and was loaded into 4 mL straws. Each straw was placed in liquid nitrogen vapor steam for 15 minutes and further immersion in liquid nitrogen at -196°C for long-term storage. After thawing, semen samples were initially evaluated for sperm motility, both total and progressive, and acrosin activity. Moreover, semen was incubated at 37°C and further assessed at 60 and 120 minutes in a thermoresistance test (TRT) for sperm motility and acrosin activity. Immediately after thawing, both progressive and total motility, and acrosin activity were lower (p < 0.05) in thawed semen than in fresh semen. During the TRT, total sperm motility and acrosin activity after 60 minutes were lower (p < 0.05) than those obtained after thawing. Similarly, total sperm motility and acrosin activity were lower (p < 0.05) after 120 minutes than at 60 minutes of the TRT. The analysis of motility and acrosin activity allowed the conclusion that both extenders have a similar capacity to preserve the integrity of sperm cells subject to freezing and thawing.

A extensão universitária frente ao isolamento social imposto pela COVID-19 University extension front of the social isolation imposed by COVID-19

Evaluación de los días de recolección y transferencia de embriones sobre las tasas de preñez en yeguas Mangalarga Marchador durante la estación de monta Avaliação do dia da colheita e da transferência de embriões equino da raça Mangalarga Marchador durante a estação de monta

Background: Induction of ovulation is a key procedure for horse assisted reproduction technologies, such as for artificial insemination (AI) and embryo transfer. The application of hCG remains as the primary ovulation-inducing agent for horse assisted reproduction, but alternatives are in demand to avoid its adverse effects, such as loss of ovulation-inducing ef­ficiency over multiple applications by hCC-antibody production. Despite reports on alternative ovulation-inducing agents, pair-wise comparisons of such agents under similar conditions have been limited. Under such scenario, the work was aimed to determine the efficiency of both hCG and Buserelin at inducing ovulation in Mangalarga Marchador mares raised in the Northeast of Brazil under an AI program.Materials, Methods & Results: Mares were initially selected based on their reproductive performance, the absence of clinical-reproductive alterations and adequate body condition score. Mares in diestrus were randomly distributed in three experimental conditions, received 5 mg of Dinoprost and were monitored daily for estrus detection. After estrus detection, ovaries were monitored by ultrasonography, in 12-h intervals, until the follicle reached 35 mm. At this time-point, ovula­tion was induced with 0.042 mg of Buserelin endovenously, with 3,000 IU hCG by an intramuscular shot, and control mares received 2 mL of saline solution, also by an intramuscular shot. Both hCG and Buserelin displayed similar efficien­cies (P > 0.05) for induction of ovulation and that both agents were effective (P < 0.05) for such purpose, since greater percentages (P < 0.05) of induction on mares treated from those of the control. Moreover, the total number of ovulations in mares treated at the end of the experiment was not different (P > 0.05) from those found in the Control. All ovulations occurred within a 72-h period after treatment. It can be observed that in mares treated with hCG or Buserelin, ovulations occurred both in more mares (P < 0.05) and at earlier time-points than mares from the control. It is also possible to note that pregnancy was not different (P > 0.05) between hCG and Buserelin groups, and that pregnancy of mares treated with ovulation-inducing factors was similar to the control.Discussion: The majority of ovulations in mares occurred within initial 48-h after treatment for both hCG and GnRH, suggesting a similar potential for horse assisted reproduction. Both hCG and Buserelin are two commonly used agents for induction of ovulation in mares. As described here, the majority of ovulations occurred within initial 48-h after treatment, a fact which can be attributed to hCG and GnRH activity, since it can happen in intervals from 36 to 48-h after treatment. Pregnancy rates did not differ among groups. These results are under the working hypothesis that hCG and Buserelin would display similar efficiencies on pregnancy rates. Despite the understanding of hCG activity on induction of ovulation due to its high specificity toward LH receptors and results from a direct effect on diminishing estradiol concentration, increasing LH, and further inducing ovulation within 48-h after treatment. In contrast, Buserelin has a similar functional property but acts upon LH synthesis and its release. In conclusion, ovulation in mares can be induced with both hCG and Buserelin, and both ovulation-inducing agents do not affect pregnancy rates.Keywords: gonadotropin, releasing factor, ovary, follicle, corpus luteum.

Objetivo: Construir conhecimento sobre Trichomonas vaginalis/tricomoníase junto à universitários do sexo masculino das áreas de Ciências Exatas e da Natureza, Tecnologia e Geociências e Informática da Universidade Federal de Pernambuco. Metodologia: Extensão universitária realizada através da Educação em Saúde nos semestres 2017-2019. Foi montado stand com painéis sobre T. vaginalis/tricomoníase e com auxílio de bancadas expostos folders, cartilhas, preservativos, lubrificantes íntimo e material de laboratório para diagnóstico da tricomoníase. Sessenta extensionistas, estudantes de graduação das Ciências Biológicas, Saúde e Médica, atuaram na transmissão e construção do conhecimento. Resultado: As ações educativas alcançaram 3.162 estudantes com idade média entre 19,65-23,05 anos de idade. O diálogo foi consolidado, mas no início alguns demonstraram timidez e no geral, declararam não conhecer às formas de transmissão e tratamento, importância epidemiológica do sexo masculino na manutenção da tricomoníase, além dos agravos à saúde masculina. Nas ações cerca de 3.500 folders sobre T. vaginalis/tricomoníase e 15.000 folhetos/cartilhas sobre HIV/AIDS, sífilis e hepatites virais, além de 25.000 preservativos peniano, 2.000 preservativos vaginal e 40.000 sachês de lubrificante íntimo, foram distribuídos. Conclusão: As ações contribuíram no processo educativo participativo, onde os universitários do sexo masculino atuaram como sujeitos reflexivos e ativos na construção do conhecimento sobre o T. vaginalis/tricomoníase e na conquista da autonomia na adoção de prevenção, levando à sustentabilidade da vida sexual saudável e segura. A Universidade é locu estratégico para promover ações inovadoras e transformadoras em Educação em Saúde que favoreçam a formação dos seus estudantes, bem como seu vínculo com a sociedade.