Phenotypic variation of Fucus ceranoides, F. spiralis and F. vesiculosus in a temperate coast (NW Portugal)

Brown algae includes several species of Fucus, reported both in the tidal and intertidal zones of cold and temperate regions. Environmental parameters induce wide biological variability in intertidal algae, manifested by alterations at several levels, and this has lead to the failure of some reports to discriminate between closely related taxa, particularly Fucus species. As the genus Fucus is widely represented on the Portuguese coast, the biometric parameters of three species (F spiralis, F. vesiculosus and F. ceranoides) collected from several sampling sites in Portugal, were studied over twelve months. Environmental parameters (water temperature, pH, dissolved oxygen, salinity, phosphorous - orthophosphate and total phosphate, nitrate, nitrite and ammonia) were analysed. The objective of this study was to understand how environmental parameters influence and establish morphological variation in the Fucus species. Canonical Correspondence Analysis (CCA), which helps define the relationships between morphological and physicochemical variables, was carried out for each species in order to determine which physicochemical parameter most affects the morphology of Fucus. The variable biometric that strongly separates the three Fucus species is the number of receptacles per thalli, and this parameter was highly correlated with F ceranoides. The two others species were distinguished principally by the height of the bigger receptacle, the midrib height of the holdfast, the height of the smaller receptacle, and the midrib width of the holdfast. The CCA analysis also showed that the dominant factor influencing morphometric parameters was salinity, being always in strict correlation with water temperatures and orthophosphate. For F ceranoides, physicochemical parameters (especially a higher concentration of orthophosphate and lower salinity) seem to influence morphological parameters, mainly in the raised number of receptacles per thalli. Salinity was the most important environmental parameter to distinguishing F spiralis and F vesiculosus in northern Portugal.FCT/CONTROL project - PDCTM/C/MAR/15266/199

Information systems for dairy herds: who are the users?

In Brazil, the use of information systems (IS) for record-keeping in dairy herds has been limited. However, in a project of the “Instituto de Zootecnia - Núcleo de Pesquisas Zootécnicas Nordeste”, Ribeirão Preto, São Paulo, a group of 46 milk producers made use of IS for as long as they participated over the life of the project from 1989 to 1999. The herds adopted the records system known as DAISY (Dairy Information System) developed at the University of Reading, England, for monitoring purposes. The present study had the objectives of characterizing these users with regard to certain socio-cultural aspects and physical characteristics of the farms. The variables studied were analyzed by means of descriptive statistics and cross tables to determine levels of association between them, which were tested by Chi-Square. For the majority of the farms monitored, milk production is the principal activity, and in spite of using modern technology, many of these producers are still selling grade C milk. The smaller herds are tending to abandon dairying, and as to the larger herds, managers of most of them became aware of the need to utilize IS during their participation in the project and subsequently opted to use IS on their own

Características termorreguladoras e desempenho de cabras leiteiras no terço inicial da lactação em clima tropical.

Resumo: Teve-se como objectivo avaliar o comportamento de características termorreguladoras, a condição corporal e a produção de leite no início da lactação de 45 cabras de diferentes tipos raciais (15 da raça Saanen, 15 cruzadas Sem Padrão Racial Definido (SPRD) x Murciana e 15 Alpinas Americanas). Foram tomadas a temperatura retal, a freqüência respiratória, o escore da condição corporal a produção diária de leite e as concentrações plasmáticas de triiodotironina (T3) e tiroxina (T4) avaliados até os 36 dias da lactação. As concentrações de T3 e T4 foram obtidas pelo método de radioimunoensaio. As variáveis meteorológicas foram registradas às 15 h, no mesmo horário da coleta dos dados fisiológicos. Os resultados obtidos indicaram que as cabras da raça Alpina Americana tiveram as maiores temperaturas retais e frequencias respiratórias, além de menores concentrações de triiodotironina e tiroxina, associados a menor produção de leite e condição corporal possivelmente como reflexo de menor adaptação ao clima. As cabras Saanen e _ Murciana SPRD apresentaram menores temperaturas retais e frequencias respiratórias, maior escore da condição corporal e concentrações séricas de triiodotironina e tiroxina. As temperaturas retais foram iguais entre os grupos genéticos _ SPRD x _ Murciana e diferente para as cabras saanen. No terço inicial de lactação animais mestiços leiteiros juntamente com as cabras Saanen, demonstraram maior adaptabilidade, bom desenvolvimento corporal e melhor desempenho lactacional. As cabras Alpinas Americanas mostraram menores respostas adaptativas e produtivas o que evidencia a importância do ambiente térmico na criação desses animais. [Thermoregulatory traits and performance of dairy goats in early lactation in tropical weather]. Abstract: The objective of this study was to evaluate physiological and performance characteristics in early lactation of dairy goats of several breeds, namely thermoregulation, body condition and milk production. Forty five females were used (15 Saanen, 15 of crosses between undefined breed and _ Murciana and 15 American Alpine). Records were made of rectal temperature, respiratory rate, body condition score and daily milk production in the 36 first days of lactation. Plasma concentrations of triiodothyronine and thyroxine were obtained by radioimmunoassay method. The meteorological variables were registered at 15 pm, at the same time as the collection of physiological indicators. Results indicate that American Alpine goats had higher rectal temperatures and respiratory frequency, lower concentration of triiodothyronine and thyroxine, associated to a smaller milk production and body condition, possibly due to the worse climate adaptation. Saanen and _ Murciana crosses presented lower rectal temperatures and respiratory frequency, higher body score and triiodothyronine and thyroxine concentrations. Rectal temperatures were similar between the genetic groups undefined breed x _ Murciana and different for Saanen goats. In the initial third of lactation crossbred goats along with Saanen goats showed greater adaptability, good physical development and better milk production. The American Alpine goats showed less productive and adaptive responses which highlights the importance of the thermal environment in the management of these animals

Evaluation of the performance of a commercial dairy herd using a computerized system of records

The aim of this study was to assess performance indexes relative to fertility and milk production in a herd of 750 cows of the Girolando breed enrolled in a dairy herd monitoring program (PMRL) developed by the Estação Experimental de Zootecnia de Ribeirão Preto, SP, Brazil from 1990 to 1999. Results showed that the indexes studied improved over the years. In the regression model some variables, such as total number of cows in the herd, interval from calving to first service, pregnancy rate at first service and pregnancy rate at all services, showed high coefficient of determination (R2 >51%), indicating that these traits responded strongly to the action recommended by the PMRL. Other traits, such as age at first calving, interval from calving to conception, number of services per conception, total milk yield per lactation and at 305 days of lactation, depend more on other factors inherent to the animal itself than on the PMRL. For this group of traits, other sources of variation were included in the analysis model, namely age of cow or number of calving, sex of the calf, genetic group, and month/season and year of calving, in an attempt to improve the R2. In both cases, the variable year of calving indirectly measured the efficiency of the system. The period studied (10 years) was not long enough to perceive the effects of certain other sources of variation such as genetic progress, which could also be involved

Thermal Transport and Rheological Properties of Hybrid Nanofluids Based on Vegetable Lubricants

Nanofluids based on vegetal oil with different wt.% of carbon nanotubes (CNT), hexagonal boron nitride (h-BN), and its hybrid (h-BN@CNT) were produced to investigate the effects of these nano-additives on the thermal conductivity and rheological properties of nanofluids. Stable suspensions of these oil/nanostructures were produced without the use of stabilizing agents. The dispersed nanostructures were investigated by SEM, EDS, XRD, and XPS, while the thermal conductivity and rheological characteristics were studied by a transient hot-wire method and steady-state flow tests, respectively. Increases in thermal conductivity of up to 39% were observed for fluids produced with 0.5 wt.% of the hybrid nanomaterials. As for the rheological properties, it was verified that both the base fluid and the h-BN suspensions exhibited Newtonian behavior, while the presence of CNT modified this tendency. This change in behavior is attributed to the hydrophobic character of both CNT and the base oil, while h-BN nanostructures have lip-lip “bonds”, giving it a partial ionic character. However, the combination of these nanostructures was fundamental for the synergistic effect on the increase of thermal conductivity with respect to their counterparts

GM 01. Study of some fertility indices of dairy herds monitored by computerized information systems

The objective of this work is to verify the tendency of some fertility indices of monitored dairy herds from 1992 to 1995. In developed countries the use of computerized information systems has contributed significantly to the increase milk production. Data from a program of monitoring dairy farms developed by the “Estação Experimental de Zootecnia de Ribeirão Preto, IZ/SAA, SP, Brasil” were studied from 1992 to 1995. The fertility indices used to assess the performance are described: a) calving interval to conception (days); b) days open; c) percentage of cows that re-calved; d) number of services per conception. There was a tendency for the calving interval to conception to decrease over the years. This indice is a good parameter to assess herd efficiency. It reflects improvements of the herds in cow fertility, heat detection efficiency and artificial insemination. The days open take into account all cows that did not yet conceive within 12 month period, hence it shows the poorest cows in the herd. Surprisely, the percentage of cows that re-calved tended to decrease over the years. This work showed that it is difficult to state if the herd performance has improved or not based only in the studied indices. The results suggested that many factors are involved when assessing dairy herd fertility indices, specially in developing countries where milk policy does not always motivate the dairy farmer to have a tight policy with his cows. It is also important to understand that over the years farmers have learnt ‘what’ and ‘how’ to record, as a consequence, some fertility indices seemed to be worse but they were more realistic than previous figures. Educational programmes for dairy farmers on the information needs and use for farm management should be supported and implemented

Parâmetros hematológicos e escore corporal de ovelhas da raça Morada Nova em ambiente quente.

Objetivou-se com este estudo analisar correlações existentes entre escore corporal e parâmetros sanguíneos de ovelhas Morada Nova, verificando-se também as possíveis influências das variáveis ambientais, como temperatura e umidade relativa do ar, além da temperatura retal, mensuradas durante o período de coleta. Utilizaram-se 227 animais de oito propriedades. Foram estimados os escores corporais e realizada colheita de uma amostra sanguínea de cada ovelha, nas quais se determinaram o hematócrito, a contagem de eritrócitos e o volume globular médio. Os parâmetros hematológicos de ovelhas Morada Nova mostraram-se diferentes das médias dos valores de referência, sendo bastante influenciados pelo escore corporal. Assim, a adoção de estratégias de manejo que permitam a manter o escore equilibrado, ao longo do ano, pode favorecer a homeostase e, consequentemente a otimização das funções orgânicas

Characterization of Cholinesterases in Plasma of Three Portuguese Native Bird Species: Application to Biomonitoring

Over the last decades the inhibition of plasma cholinesterase (ChE) activity has been widely used as a biomarker to diagnose organophosphate and carbamate exposure. Plasma ChE activity is a useful and non-invasive method to monitor bird exposure to anticholinesterase compounds; nonetheless several studies had shown that the ChE form(s) present in avian plasma may vary greatly among species. In order to support further biomonitoring studies and provide reference data for wildlife risk-assessment, plasma cholinesterase of the northern gannet (Morus bassanus), the white stork (Ciconia ciconia) and the grey heron (Ardea cinerea) were characterized using three substrates (acetylthiocholine iodide, propionylthiocholine iodide, and S-butyrylthiocholine iodide) and three ChE inhibitors (eserine sulphate, BW284C51, and iso-OMPA). Additionally, the range of ChE activity that may be considered as basal levels for non-exposed individuals was determined. The results suggest that in the plasma of the three species studied the main cholinesterase form present is butyrylcholinesterase (BChE). Plasma BChE activity in non-exposed individuals was 0.48±0.11 SD U/ml, 0.39±0.12 SD U/ml, 0.15±0.04 SD U/ml in the northern gannet, white stork and grey heron, respectively. These results are crucial for the further use of plasma BChE activity in these bird species as a contamination bioindicator of anti-cholinesterase agents in both wetland and marine environments. Our findings also underscore the importance of plasma ChE characterization before its use as a biomarker in biomonitoring studies with birds