Effect of ageing and MAP on quality of striploin from cattle of Holstein-Friesian breed

There have been determined the features of m. longissimus lumborum steaks from young cattle-for-fattening of Holstein-Friesian breed, Polish black-and-white variety. There were measured pH values, basic chemical composition and colour parameters. The meat was subjected to moist-ageing for 12 days and, next, stored in modified atmosphere for the following 10 days. The amount of heat loss in relation to the temperature of thermal processing was determined. Texture parameters were studied instrumentally and organoleptically. The studied muscles from young cattle-for-fattening characterised with proper and similar pH values. The average fat content was 4.37%. The surface colour of the studied dorsal muscle was relatively bright, the average value L*=37.97, and on the cross-section L*=32.97. The average value of the muscle surface's 'redness' was a*=18.98, whereas cross-section's a*=20.27. The amounts of heat leakages were rising along with the increase of temperature from 11.24 to 37.14%. Ageing and storing in MAP led to a significant decrease in the amounts of heat leakages. Ageing and storing in MAP had a significant influence on decreasing shear force and on increasing the organoleptic evaluation marks of the m. longissimus lumborum after thermal processing, which shows that the muscle may become culinary meat with features accepted by consumers.(AU)

Maturation period of bovine meat subjected to vacuum modifies physical-chemical and microbiological parameters / Período de maturação promove alterações dos parâmetros físico-químicos e microbiológicos da carne bovina submetida a vácuo

The objective of this research was to evaluate the effects of vacuum maturation on the changes of beef quality up to 9 days of refrigeration. The Longissimus dorsi muscle from 20 crossbred (Charolais x Angus) cattle was used in the research. The samples were distributed in three vacuum-ageing periods: T0 = zero (no vacuum), T3 = 3, T7 = 7 and T9 = 9 days, with five replicates for each period evaluated. During the ageing period, pH, color (L*, a*, b*), hue, chroma, water retention capacity, cooking loss and shear force were determined. The progress of vacuum-ageing changed (p 0.05) chroma, hue and shear force. The remaining parameters did not change significantly during evaluations. According to the results, an ageing period up to 9 days influences instrumental beef quality, i.e. it is lower than the recommended by the industry for ageing meat, which influences the consumers" purchase decision.

A pesquisa teve como objetivo avaliar os efeitos da maturação a vácuo sobre as mudanças de qualidade dos bifes de bovinos até 9 dias de refrigeração. O músculo Longissimus dorsi de 20 bovinos cruzados (Charolês x Angus) foram utilizados na pesquisa. As amostras foram distribuídas em três períodos de maturação a vácuo: T0 = zero (sem vácuo), T3 = 3, T7 = 7 e T9 = 9 dias, com cinco repetições, em cada período avaliado. Durante o período de maturação foi determinado o pH, a coloração (L*, a*, b*), tonalidade, croma, capacidade de retenção de água, perda por cocção e força de cisalhamento das amostras. Verificou-se que o progresso da maturação da carne a vácuo altera (p 0,05) o croma, a tonalidade, e a força de cisalhamento. Os demais parâmetros avaliados não apresentaram modificações significativas durante as avaliações. De acordo com os resultados, pode-se afirmar que o período de maturação até 9 dias influencia na qualidade instrumental da carne bovina, ou seja, um período inferior ao recomendado pela indústria para maturação da carne, que por sua vez, influencia na decisão de compra dos consumidores.

Maturation period of bovine meat subjected to vacuum modifies physical-chemical and microbiological parameters / Período de maturação promove alterações dos parâmetros físico-químicos e microbiológicos da carne bovina submetida a vácuo

The objective of this research was to evaluate the effects of vacuum maturation on the changes of beef quality up to 9 days of refrigeration. The Longissimus dorsi muscle from 20 crossbred (Charolais x Angus) cattle was used in the research. The samples were distributed in three vacuum-ageing periods: T0 = zero (no vacuum), T3 = 3, T7 = 7 and T9 = 9 days, with five replicates for each period evaluated. During the ageing period, pH, color (L*, a*, b*), hue, chroma, water retention capacity, cooking loss and shear force were determined. The progress of vacuum-ageing changed (p 0.05) chroma, hue and shear force. The remaining parameters did not change significantly during evaluations. According to the results, an ageing period up to 9 days influences instrumental beef quality, i.e. it is lower than the recommended by the industry for ageing meat, which influences the consumers" purchase decision.(AU)

A pesquisa teve como objetivo avaliar os efeitos da maturação a vácuo sobre as mudanças de qualidade dos bifes de bovinos até 9 dias de refrigeração. O músculo Longissimus dorsi de 20 bovinos cruzados (Charolês x Angus) foram utilizados na pesquisa. As amostras foram distribuídas em três períodos de maturação a vácuo: T0 = zero (sem vácuo), T3 = 3, T7 = 7 e T9 = 9 dias, com cinco repetições, em cada período avaliado. Durante o período de maturação foi determinado o pH, a coloração (L*, a*, b*), tonalidade, croma, capacidade de retenção de água, perda por cocção e força de cisalhamento das amostras. Verificou-se que o progresso da maturação da carne a vácuo altera (p 0,05) o croma, a tonalidade, e a força de cisalhamento. Os demais parâmetros avaliados não apresentaram modificações significativas durante as avaliações. De acordo com os resultados, pode-se afirmar que o período de maturação até 9 dias influencia na qualidade instrumental da carne bovina, ou seja, um período inferior ao recomendado pela indústria para maturação da carne, que por sua vez, influencia na decisão de compra dos consumidores.(AU)

a) O estresse térmico afeta a viabilidade dos espermatozoides do coral Mussismilia harttii: relação entre morfologia, motilidade, envelhecimento celular e estresse oxidativo

Os recifes de coral encontram-se cada vez mais ameaçados em virtude do aquecimento gobal, colocando em risco toda a biodiverdidade marinha, bem como todos os serviços ecossistemicos provenientes desses ambientes. Dentre os muitos prejuízos causados pelas mudanças climáticas, os impactos na reprodução sexuada dos corais construtores de recifes são bastante preocupantes, devido a grande sensibilidade dos gametas a essas alterações ambientais, podendo comprometer a fertilização e formação de novos indivíduos. Dessa forma, o objetivo desse estudo foi avaliar o efeito do estresse térmico na qualidade espemática do coral construtor Mussismilia harttii. Para isso, inicialmente, em duas noites consecutivas de desova, foi realizada uma caracterização espermática ao longo do envelhecimento celular (tempo de vida após a desova) dos espermatozoides da M. harttii mantidos na mesma temperatura do mar do Recife de Fora (26 ± 0,50 °C). Em cada tempo de análise (0, 5 e 10h após a desova) foram mensurados o pH, a motilidade, a morfologia, a concentração de glutationa (GSH) e de peroxidação lipídica (LPO). Também propomos uma classificação detalhada dos tipos de anormalidades encontradas na cabeça e no flagelo dos espermatozoides, uma vez que essa descrição nunca foi antes abordada na literatura para os corais. Além disso, os espermatozoides foram expostos, ao longo das 10 horas de avaliação, à duas projeções de aumento da temperatura previsto para 2100, segundo o Painel Intergovenamental sobre Mudanças Climáticas (IPCC). A primeira projeção estima um aumento da temperatura em até 1,7 °C (27,7 ± 0,37 ºC), enquanto a segunda projeta uma elevação térmica de até 4,8 °C (30,8 ± 0,46 ºC). Em cada tempo de avaliação também foram mensurados o pH, motilidade, morfologia, GSH e LPO dos espermatozoides. Em suma, observamos durante a caracterização espermática (26°C) que as principais anormalidades encontradas são no flagelo. Além disso, vimos que a primeira noite de desova possui, de um modo geral, melhores características do que os da segunda noite. No entanto, independentemente disso, foi evidente o efeito do envelhecimento celular na redução da qualidade espermática. Observamos que à medida que os espermatozoides envelheciam, aumentava o estresse oxidativo, caracterizado pela redução na concentração de GSH e aumento de LPO. Além disso, vimos que o estresse oxidativo está intimamente relacionado com o aumento do percentual de anormalidades nos espermatozoides e que o aumento de células com danos tem impacto negativo na motilidade espermática. Também descobrimos que o aumento da temperatura da água, seja na maior ou menor intensidade das projeções testadas, potencializou os efeitos negativos encontrados em 26°C. Nossos achados reforçam o alerta da gravidade que o aquecimento do oceano pode causar aos recifes de coral e em todo o ambiente marinho.

Coral reefs are increasingly threatened by global warming, putting at risk all marine biodiversity, as well as all ecosystem services from these environments. Among the many damages caused by climate change, the impacts on the sexual reproduction of reef-building corals are quite worrying, due to the great sensitivity of gametes to these environmental changes, which can compromise fertilization and the formation of new individuals. Thus, the aim of this study was to evaluate the effect of thermal stress on the sperm quality of the reef-building coral Mussismilia harttii. For this purpose, initially, on two consecutive spawning nights, a sperm characterization was carried out during cell aging (lifespan after spawning) of M. harttii spermatozoa kept at the same sea temperature as Recife de Fora (26 ± 0.50 ° C). At each analysis time (0, 5 and 10h after spawning), pH, motility, morphology, glutathione (GSH) and lipid peroxidation (LPO) concentration were measured. Also we propose a detailed classification of the types of abnormalities found in the head and flagellum of sperm, since this description has never been addressed in the literature for the corals. In addition, the spermatozoa were exposed, during the 10 hours of evaluation, to two projections of increased temperature predicted for 2100, according to the Intergovernmental Panel on Climate Change (IPCC). The first projection estimates an increase in temperature of up to 1.7 °C (27.7 ± 0.37 °C), while the second projects a thermal rise of up to 4.8 °C (30.8 ± 0.46 °C). At each time of evaluation, pH, motility, morphology, GSH and LPO of sperm were also measured. Water temperature of the aquariums was controlled by an automatic system (Reef Angel Controller) using 15,000 W heaters and temperature recorders (HOBO U22-001 Data Logger-). In short, we observed during sperm characterization (26 ° C) that the main abnormalities found are in the flagellum. Furthermore, we saw that the first night of spawning has, in general, better characteristics than those of the second night. However, regardless of that, the effect of cell aging on reducing sperm quality was evident. We observed that as the sperm aged, oxidative stress increased, characterized by reduced concentration and GSH and increased LPO. In addition, we have seen that oxidative stress is closely related to the increase in the percentage of sperm abnormalities and that the increase in damaged cells has a negative impact on sperm motility. We also found that the increase in water temperature, whether at the higher or lower intensity tested projection, potentiated the negative effects found at 26 °C. Our findings reinforce of the gravity that warming the ocean can cause to coral reefs and throughout the marine environment.

Age-related changes in activity of catalase in selected bovine muscles

Background: The unavoidable consequence of ageing process is oxidative stress which is harmful to cells. Muscles asa post-mitotic cells are especially susceptible for it. They are protected by antioxidants. One of the main antioxidantenzymes is catalase (CAT). Although muscles were extensively examined for antioxidant defense, there is a lack of comparative study regarding CAT activity in skeletal muscles, heart muscle and diaphragm in cows. The aim of present studywas investigate the link between age related alterations and antioxidant defense system and confirmation that CAT activitydepends on age and type of muscle tissue dependent on metabolic rate.Materials, Methods & Results: Samples of skeletal muscles, heart and diaphragm were collected from healthy HolsteinFriesian cows aged between 14 and 27 months (n = 12; sexually mature) and female calves aged between 2 weeks and 2months (n = 9; sexually immature) in slaughterhouse. The enzyme activity was measured by spectrophotometric method.Additionally the presence of CAT was confirmed by SDS-PAGE separation and detected by zymography. In current investigation CAT activity in heart and diaphragm showed significantly higher (P < 0.05) values than in skeletal muscles.Moreover, CAT activity was higher in cows than in calves in heart (0.28 ± 0.044 U /mg protein vs. 0.4 ± 0.035) as well asin diaphragm (0.27 ± 0.047 vs 0.37 ± 0.077), however in skeleton muscles there were no significant differences betweenexamined animals (0.076 ± 0.016 vs 0.084 ± 0.0197). According to received results CAT activity increased during agingin heart and diaphragm while in skeleton muscles age-related changes were not observed.Discussion: Skeletal muscles are particularly vulnerable to oxidative stress because...(AU)

Age-related changes in activity of catalase in selected bovine muscles

Background: The unavoidable consequence of ageing process is oxidative stress which is harmful to cells. Muscles asa post-mitotic cells are especially susceptible for it. They are protected by antioxidants. One of the main antioxidantenzymes is catalase (CAT). Although muscles were extensively examined for antioxidant defense, there is a lack of comparative study regarding CAT activity in skeletal muscles, heart muscle and diaphragm in cows. The aim of present studywas investigate the link between age related alterations and antioxidant defense system and confirmation that CAT activitydepends on age and type of muscle tissue dependent on metabolic rate.Materials, Methods & Results: Samples of skeletal muscles, heart and diaphragm were collected from healthy HolsteinFriesian cows aged between 14 and 27 months (n = 12; sexually mature) and female calves aged between 2 weeks and 2months (n = 9; sexually immature) in slaughterhouse. The enzyme activity was measured by spectrophotometric method.Additionally the presence of CAT was confirmed by SDS-PAGE separation and detected by zymography. In current investigation CAT activity in heart and diaphragm showed significantly higher (P < 0.05) values than in skeletal muscles.Moreover, CAT activity was higher in cows than in calves in heart (0.28 ± 0.044 U /mg protein vs. 0.4 ± 0.035) as well asin diaphragm (0.27 ± 0.047 vs 0.37 ± 0.077), however in skeleton muscles there were no significant differences betweenexamined animals (0.076 ± 0.016 vs 0.084 ± 0.0197). According to received results CAT activity increased during agingin heart and diaphragm while in skeleton muscles age-related changes were not observed.Discussion: Skeletal muscles are particularly vulnerable to oxidative stress because...

Teste de deterioração controlada em sementes de quatro espécies de orquídeas para avaliação do comportamento fisiológico / Controlled deterioration test in seeds of four orchids’ species to evaluate the physiological behavior

Uma alternativa para conservação de espécies é um banco de sementes, onde é possível conservar e propagar estas plantas, porém para isto é necessário se ter uma noção da qualidade das sementes estocadas. Uma alternativa é utilizar testes de vigor, entre eles a deterioração controlada. O objetivo deste trabalho foi avaliar o efeito da deterioração controlada sobre sementes de orquídeas e determinar qual o tempo de exposição destas a este tipo de tratamento. Sementes de Cattleya schilleriana, C. tigrina, C. crispata e C. labiata foram submetidas à deterioração de zero a 48h a 43°C. Para sementes de C. crispata não foi encontrado um período adequado para o teste de deterioração controlada. Recomenda-se para as sementes de C. tigrina, C. labiata e C. schilleriana a utilização de 27 h a 43°C, todavia variáveis como o tempo e a temperatura ainda precisam ser melhores estabelecidos para este grupo de plantas. O teste de tetrazólio não foi eficiente para avaliar a qualidade das sementes após a deterioração controlada.

An alternative for conservation of this species is seed banking, based in that is possible to make conservation and propagations of the endangered species. But for this the seed quality must be monitored. Vigour tests can offer an option, and one of this is the controlled deterioration, which expose the seeds with high moisture to high temperatures during a determined period of time. The present work aimed to evaluate the controlled deterioration test over four orchid species in different times. Seeds of C. schilleriana, C. tigrina, C. crispata and C. labiata was submitted to deterioration from times ranging from zero to 48h at 43°C. For Cattleya crispata it was not found a effective time for the test. did not suffer any deterioration at any time. It is recommended for C. tigrina, C. labiata and C. schilleriana the use of 27 h at 43°C. However, time and temperature should be better studied for this group of plants. Tetrazolium test was not efficient to evaluate the seed quality after controlled deterioration.

Teste de deterioração controlada em sementes de quatro espécies de orquídeas para avaliação do comportamento fisiológico / Controlled deterioration test in seeds of four orchids species to evaluate the physiological behavior

Uma alternativa para conservação de espécies é um banco de sementes, onde é possível conservar e propagar estas plantas, porém para isto é necessário se ter uma noção da qualidade das sementes estocadas. Uma alternativa é utilizar testes de vigor, entre eles a deterioração controlada. O objetivo deste trabalho foi avaliar o efeito da deterioração controlada sobre sementes de orquídeas e determinar qual o tempo de exposição destas a este tipo de tratamento. Sementes de Cattleya schilleriana, C. tigrina, C. crispata e C. labiata foram submetidas à deterioração de zero a 48h a 43°C. Para sementes de C. crispata não foi encontrado um período adequado para o teste de deterioração controlada. Recomenda-se para as sementes de C. tigrina, C. labiata e C. schilleriana a utilização de 27 h a 43°C, todavia variáveis como o tempo e a temperatura ainda precisam ser melhores estabelecidos para este grupo de plantas. O teste de tetrazólio não foi eficiente para avaliar a qualidade das sementes após a deterioração controlada.(AU)

An alternative for conservation of this species is seed banking, based in that is possible to make conservation and propagations of the endangered species. But for this the seed quality must be monitored. Vigour tests can offer an option, and one of this is the controlled deterioration, which expose the seeds with high moisture to high temperatures during a determined period of time. The present work aimed to evaluate the controlled deterioration test over four orchid species in different times. Seeds of C. schilleriana, C. tigrina, C. crispata and C. labiata was submitted to deterioration from times ranging from zero to 48h at 43°C. For Cattleya crispata it was not found a effective time for the test. did not suffer any deterioration at any time. It is recommended for C. tigrina, C. labiata and C. schilleriana the use of 27 h at 43°C. However, time and temperature should be better studied for this group of plants. Tetrazolium test was not efficient to evaluate the seed quality after controlled deterioration.(AU)

Protein and lipid peroxidation intensity in cows and female calves

Background: Reactive oxygen species alter cell membrane permeability and cause the damage to macromolecules due to peroxidative processes. The question was stated whether peroxidative processes are influenced by age and metabolic rate of particular tissue in cattle. The aim of current study was the investigation of age-related changes in lipid and protein peroxidation in chosen bovine tissues. The samples of liver, kidneys, heart and muscles were chosen, based on specifi c metabolic rate, to compare the differences between different types of tissues.Materials, Methods & Results: The samples of tissues were taken from healthy cows aged between 14 and 27 months (n = 13) and female calves aged between 2 weeks and 2 months (n = 12) immediately after slaughter. Tissues were homogenized, centrifuged and the supernatant was used for further determinations. The lipid peroxidation intensity was examined by the estimation of the content of intermediates (RC-DEPPD) and end products (TBARS) of this process. The protein peroxidative processes were measured by spectrophotometric (SH groups content) and spectrofluorimetric (Formylokinurenine and Bityrosine concentration) methods. Obtained results provided with the information that the intensity of peroxidative processes measured in present study differed significantly between cows and calves. Differences were related to metabolic...(AU)

The age-related changes in SOD activity in bovine (Bos taurus) reproductive organs

Background: The appearance of reactive oxygen species (ROS) is connect with oxidative energy production particularlyin reproductive organs. They characterize by increased metabolism, which may change during ageing. Their increasecould be dangerous for germ cells. That is why the antioxidant protection is need. One of the main antioxidative enzymeis superoxide dismutase (SOD) which could be regulated by steroid hormones through genomic mechanism of action. Buttheir level changed during ageing and maturation. However, there is still lack information about ageing alteration of SODactivity in bovine especially in reproductive organs.Materials, Methods & Results: The material for experiment consisted of reproductive organs: uterus (which was separatedinto endometrium and myometrium), both ovaries and corpus luteum collected immediately after slaughter at the slaughterhouse. Samples were taken from healthy cows aged between 16-24 months (n = 15) during luteal phase of cycle and femalecalves aged between 2 weeks and 2 months (n = 12) Total SOD activity was measured in homogenates of reproductiveorgans by use of the spectrophotometric method. PAGE electrophoresis was performed and Western blotting techniquewith specific anti-SOD antibodies as well as zymography confirmed the presence of enzymatic protein and the activity ofSOD isoenzymes. The results of spectrophotometric determinations showed significant influence of age on SOD activityin examined tissues. The SOD activity not indicate significant differences between examined reproductive organs in thegroup of cows but higher level was noticed in myometrium while the lowest in corpus luteum but the differences betweenovaries in cows were not observed. In the group of female calves as well as in the group of cows the differences betweenSOD activity in reproductive organs were not observed. The higher level was noticed in ovaries but the lower level wasobserved in myometrium...

The age-related changes in SOD activity in bovine (Bos taurus) reproductive organs

Background: The appearance of reactive oxygen species (ROS) is connect with oxidative energy production particularlyin reproductive organs. They characterize by increased metabolism, which may change during ageing. Their increasecould be dangerous for germ cells. That is why the antioxidant protection is need. One of the main antioxidative enzymeis superoxide dismutase (SOD) which could be regulated by steroid hormones through genomic mechanism of action. Buttheir level changed during ageing and maturation. However, there is still lack information about ageing alteration of SODactivity in bovine especially in reproductive organs.Materials, Methods & Results: The material for experiment consisted of reproductive organs: uterus (which was separatedinto endometrium and myometrium), both ovaries and corpus luteum collected immediately after slaughter at the slaughterhouse. Samples were taken from healthy cows aged between 16-24 months (n = 15) during luteal phase of cycle and femalecalves aged between 2 weeks and 2 months (n = 12) Total SOD activity was measured in homogenates of reproductiveorgans by use of the spectrophotometric method. PAGE electrophoresis was performed and Western blotting techniquewith specific anti-SOD antibodies as well as zymography confirmed the presence of enzymatic protein and the activity ofSOD isoenzymes. The results of spectrophotometric determinations showed significant influence of age on SOD activityin examined tissues. The SOD activity not indicate significant differences between examined reproductive organs in thegroup of cows but higher level was noticed in myometrium while the lowest in corpus luteum but the differences betweenovaries in cows were not observed. In the group of female calves as well as in the group of cows the differences betweenSOD activity in reproductive organs were not observed. The higher level was noticed in ovaries but the lower level wasobserved in myometrium...(AU)

Protein and lipid peroxidation intensity in cows and female calves

Background: Reactive oxygen species alter cell membrane permeability and cause the damage to macromolecules due to peroxidative processes. The question was stated whether peroxidative processes are influenced by age and metabolic rate of particular tissue in cattle. The aim of current study was the investigation of age-related changes in lipid and protein peroxidation in chosen bovine tissues. The samples of liver, kidneys, heart and muscles were chosen, based on specifi c metabolic rate, to compare the differences between different types of tissues.Materials, Methods & Results: The samples of tissues were taken from healthy cows aged between 14 and 27 months (n = 13) and female calves aged between 2 weeks and 2 months (n = 12) immediately after slaughter. Tissues were homogenized, centrifuged and the supernatant was used for further determinations. The lipid peroxidation intensity was examined by the estimation of the content of intermediates (RC-DEPPD) and end products (TBARS) of this process. The protein peroxidative processes were measured by spectrophotometric (SH groups content) and spectrofluorimetric (Formylokinurenine and Bityrosine concentration) methods. Obtained results provided with the information that the intensity of peroxidative processes measured in present study differed significantly between cows and calves. Differences were related to metabolic...

Quality of aged shoulder from lambs fed with different oldman saltbush hay levels (Atriplex nummularia) / Qualidade da paleta maturada de cordeiros alimentados com diferentes níveis de feno de erva-sal (Atriplex nummularia)

This study assessed the effects of different levels of oldman saltbush hay and ageing time on the physical characteristics of Santa Inês lamb meat. Sixty shoulders from 32 male lambs fed with 30, 40, 50 or 60% oldman saltbush hay for 60 days were vacuum-packaged and stored in a refrigerator at 0 ± 1°C for 0, 7 or 14 days of ageing. The shear force, cooking loss and water holding capacity were 3.06kgf cm-2, 37.28% and 76.71%, respectively, and there were no significant changed by studied factors (P>0.05).(AU)

Objetivou-se com este trabalho avaliar o efeito da inclusão de diferentes níveis de feno de erva-sal e tempo de maturação sobre as características físicas da carne de cordeiros Santa Inês. Sessenta paletas apartir de 32 cordeiros machos, alimentados com 30, 40, 50 e 60% de feno de erva-sal por 60 dias foram embaladas a vácuo e mantidas sob refrigeração a 0±1oC por 0, 7 e 14 dias de maturação. A força de cisalhamento, perda por cocção e capacidade de retenção de água não foram influenciados (P>0,05) pelos fatores estudados, apresentando valores médios de 3,06kgf cm-2, 37,28% e 76,71%, respectivamente.(AU)

Relação da idade na presença de bactérias resistentes a antimicrobianos em rebanhos leiteiros no Rio Grande do Sul / Age related to the presence of antimicrobial resistant bacteria in twenty one dairy herds in Rio Grande do Sul, Brazil

[...] As bactérias foram isoladas de amostras de leite compostas de todos os quartos mamários de cada vaca após descartar os primeiros três ou quatro jatos de leite. Para acessar os potenciais fatores de risco, características dos animais foram obtidas através de uma entrevista com os produtores. Os exames laboratoriais foram realizados de acordo com as recomendações do National Mastitis Council. Um total de 242 isolados foi obtido de 195 vacas a partir da amostra do rebanho total (251 vacas). A prevalência de infecções foi descrita em grupos de acordo com o perfil epidemiológico: bactérias ambientais, contagiosas e outras. Estas perfizeram 57,3 por cento, 26,3 por cento e 11,2 por cento, respectivamente, dos animais amostrados. Testes de suscetibilidade antimicrobiana contra 12 diferentes antimicrobianos foram realizados em 159 isolados. No total, 30 por cento dos isolados testados mostraram resistência a pelo menos três grupos diferentes de antimicrobianos e foram classificados como multirresistentes. Foram observadas as freqüências mais elevadas de resistência contra a ampicilina para os estafilococos coagulase-negativo, seguida de eritromicina para estafilococos coagulase-positivo e tetraciclina para estreptococos. A análise de regressão logística mostrou uma relação significativa entre a idade das vacas e a presença de estafilococos coagulase-positivo multirresistentes e distribuição de classes diferentes de bactérias nos diferentes estratos etários, o que sugere uma concorrência dinâmica ao longo do tempo (p < 0,05). Animais com três a quatro anos tiveram 13,7 vezes mais chances (IC95 por cento 1,4 - 130,2, p = 0,02) de ter estafilococos coagulase-positivo multirresistentes em comparação com aqueles com dois ou três anos. O tempo de exposição a agentes infecciosos e consequentes terapias sugere uma maior chance de colonização do úbere por patógenos resistentes devido à pressão de seleção repetida durante a vida.(AU)

[...] Bacteria were isolated from composite milk samples obtained from all quarters of each cow after discarding the initial three or four streams of milk. To access potential risk factors, animal characteristics were obtained through an interview with the producers. Laboratory tests were done according to National Mastitis Council recommendations. A total of 242 isolates was obtained from 195 cows out of 251 cows sampled. The prevalence of animal infections was described in groups according to the epidemiological profile: environmental, contagious and other bacteria. These were 57.3 percent, 26.3 percent and 11.2 percent, respectively of the sampled animals. Antimicrobial susceptibility tests against 12 different antimicrobials were performed in 159 isolates. Altogether, 30 percent of the isolates tested showed resistance to at least three different antimicrobial groups and were classified as multidrug-resistant. Higher frequencies of resistance were observed against ampicillin to coagulase-negative staphylococci, followed by erythromycin to coagulase-positive staphylococci and tetracycline to streptococci. The logistic regression analysis showed a significant relationship between age of the cows and presence of multidrug-resistant coagulase-positive staphylococci and distribution of different class of bacteria, suggesting a competition dynamic throughout the ages (p < 0.05). Animals with three to four years old had 13.7 times more chances (IC95 percent 1.4 - 130.2; p = 0,02) to have multidrug-resistant coagulase-positive staphylococci compared to those with two to three years. Time of exposure to infectious agents and consequent therapies suggests a greater chance of udder's colonization by resistant pathogens due to repeatedly selection pressure during lifetime.(AU)

The relevance of age and nutritional status on the mating competitiveness of medfly males (Diptera: Teprhitidae)

Results of previous investigations trying to ascertain which physiological factors are more important to the mating success of medfly males are controversial. In part, this controversy owes to the fact that each factor was evaluated by an independent study using different experimental designs and populations. In the present study we compare the roles of age and nutritional status (immature and adult phases) on the mating competitiveness of Ceratitis capitata (Wiedemann, 1824) males. Three parameters were used to evaluate the male mating success: calling behavior (pheromone emission), lek participation and copulation (ability to be chosen by a female). Females gave preference to the males that were given a high protein diet in the larval phase. By contrast, females did not give preference to males that had been well-nourished in the adult phase only. The other parameters evaluated followed the same pattern: young males and males that had been fed a high protein diet during their immature phase had a greater participation in leks and called more often than older males and males that had been fed a diet poor in protein during their larval phase. Therefore, we conclude that the mating success of C. capitata males is determined both by age and nourishment during the immature stage.

The relevance of age and nutritional status on the mating competitiveness of medfly males (Diptera: Teprhitidae)

Results of previous investigations trying to ascertain which physiological factors are more important to the mating success of medfly males are controversial. In part, this controversy owes to the fact that each factor was evaluated by an independent study using different experimental designs and populations. In the present study we compare the roles of age and nutritional status (immature and adult phases) on the mating competitiveness of Ceratitis capitata (Wiedemann, 1824) males. Three parameters were used to evaluate the male mating success: calling behavior (pheromone emission), lek participation and copulation (ability to be chosen by a female). Females gave preference to the males that were given a high protein diet in the larval phase. By contrast, females did not give preference to males that had been well-nourished in the adult phase only. The other parameters evaluated followed the same pattern: young males and males that had been fed a high protein diet during their immature phase had a greater participation in leks and called more often than older males and males that had been fed a diet poor in protein during their larval phase. Therefore, we conclude that the mating success of C. capitata males is determined both by age and nourishment during the immature stage.

The relevance of age and nutritional status on the mating competitiveness of medfly males (Diptera: Teprhitidae)

Results of previous investigations trying to ascertain which physiological factors are more important to the mating success of medfly males are controversial. In part, this controversy owes to the fact that each factor was evaluated by an independent study using different experimental designs and populations. In the present study we compare the roles of age and nutritional status (immature and adult phases) on the mating competitiveness of Ceratitis capitata (Wiedemann, 1824) males. Three parameters were used to evaluate the male mating success: calling behavior (pheromone emission), lek participation and copulation (ability to be chosen by a female). Females gave preference to the males that were given a high protein diet in the larval phase. By contrast, females did not give preference to males that had been well-nourished in the adult phase only. The other parameters evaluated followed the same pattern: young males and males that had been fed a high protein diet during their immature phase had a greater participation in leks and called more often than older males and males that had been fed a diet poor in protein during their larval phase. Therefore, we conclude that the mating success of C. capitata males is determined both by age and nourishment during the immature stage.

Testes de vigor em sementes de Crambe abyssinica

The objective was to verify vigor tests efficiency in the evaluation the crambe seeds physiological quality. Four lots of crambe seeds of cultivar 'FMS Brilhante' were submitted to the following standard germination and vigour test (first germination count, length and dry mass of seedling, seedling emergence in sand and field, electrical conductivity, accelerated ageing and controlled deterioration). The experiment was conducted in a randomized complete block design for test, evaluating the lots effect. The seedling emergence in field test and the controlled deterioration test at pre-moistened seeds at 15% and maintained under 42°C/48h and at 25% under 45°C/36h are efficients classifying the crambe seeds lots in different vigour levels.

O objetivo deste trabalho foi verificar a eficiência de testes de vigor na avaliação da qualidade fisiológica de sementes de crambe. Para isso, quatro lotes de sementes de crambe da cultivar 'FMS Brilhante' foram submetidos aos testes de germinação e vigor (primeira contagem de germinação, comprimento e massa seca de plântula, emergência de plântulas em areia e campo, condutividade elétrica, envelhecimento acelerado e deterioração controlada), em delineamento inteiramente casualizado com quatro repetições. Os testes de emergência de plântulas em campo e de deterioração controlada com sementes pré umedecidas a 15% e mantidas a 42°C/48 horas e a 25% a 45°C/36 horas são eficientes na classificação dos lotes de sementes de crambe em distintos níveis de vigor.

Testes de vigor em sementes de Crambe abyssinica

The objective was to verify vigor tests efficiency in the evaluation the crambe seeds physiological quality. Four lots of crambe seeds of cultivar 'FMS Brilhante' were submitted to the following standard germination and vigour test (first germination count, length and dry mass of seedling, seedling emergence in sand and field, electrical conductivity, accelerated ageing and controlled deterioration). The experiment was conducted in a randomized complete block design for test, evaluating the lots effect. The seedling emergence in field test and the controlled deterioration test at pre-moistened seeds at 15% and maintained under 42°C/48h and at 25% under 45°C/36h are efficients classifying the crambe seeds lots in different vigour levels.

O objetivo deste trabalho foi verificar a eficiência de testes de vigor na avaliação da qualidade fisiológica de sementes de crambe. Para isso, quatro lotes de sementes de crambe da cultivar 'FMS Brilhante' foram submetidos aos testes de germinação e vigor (primeira contagem de germinação, comprimento e massa seca de plântula, emergência de plântulas em areia e campo, condutividade elétrica, envelhecimento acelerado e deterioração controlada), em delineamento inteiramente casualizado com quatro repetições. Os testes de emergência de plântulas em campo e de deterioração controlada com sementes pré umedecidas a 15% e mantidas a 42°C/48 horas e a 25% a 45°C/36 horas são eficientes na classificação dos lotes de sementes de crambe em distintos níveis de vigor.

Age and growth estimation of bigeye tuna, Thunnus obesus (Teleostei: Scombridae) in the southwestern Atlantic

The purpose of the current study was to supply the first information on age and growth for Thunnus obesus caught in the equatorial south-western Atlantic using dorsal spines, an approach that has been successfully employed for ageing tuna species. The study was conducted using a multi-model inference based on information theory for back-calculated and observed length-at-age data. Uncertainty associated with the parameter estimation was verified and results were compared to other accounts on the species, considering both the statistical and methodological contexts. Samples were collected in Natal city (Rio Grande do Norte State, Brazil) from February 1999 to January 2000, of tuna vessels and from surveys, aimed at providing information on the Brazilian Exclusive Economic Zone (EEZ) in the area around São Pedro and São Paulo Archipelago. Validation using marginal increment indicated that one ring is deposited per year. Mean length-at-age ranged of 54.3 to 177.5 cm (fork length) for ages 1 to 9 years. Von Bertalanffy, Richards, and Gompertz models were considered suitable for the bigeye tuna. Hence, the model-averaged asymptotic length ¯L∞ was estimated. The averaged model generated in the present study by back-calculation was considered appropriate for describing the growth of T. obesus.(AU)

A proposta do presente estudo foi fornecer a primeira informação sobre idade e crescimento de Thunnus obesus, capturado no Atlântico sudoeste equatorial usando espinhos dorsais, uma abordagem que tem sido utilizada com sucesso na determinação de idade de espécies de atuns. O estudo foi conduzido usando uma inferência de multi-modelos baseada na teoria de informação avaliada para dados de comprimento por idade retrocalculados e observados. Incertezas associadas aos parâmetros foram verificadas e os resultados foram comparados aos de outros estudos realizados para esta espécie, considerando os contextos estatísticos e metodológicos. As amostras foram coletadas na cidade de Natal (estado do Rio Grande do Norte, Brasil) de fevereiro de 1999 a janeiro de 2000, provenientes de embarcações comerciais e também prospecções, cujo objetivo foi prover informações sobre a Zona Econômica Exclusiva (ZEE) na área do entorno do Arquipélago de São Pedro e São Paulo. A validação usando incremento marginal indicou a deposição de um anel anual. Os comprimentos médios por idade variaram entre 54.3 a 175.7 cm (comprimento furcal) para idades de 1 a 9 anos. Os modelos Von Bertalanffy, Richards e Gompertz foram considerados adequados para a albacora bandolim e, desta forma, o comprimento assintótico para um modelo médio (¯L∞) foi estimado. O modelo médio gerado no presente estudo a partir dos comprimentos retrocalculados foi considerado apropriado para descrever o crescimento de T. obesus capturada no Atlântico.(AU)