Distinct patterns of nitrate reductase activity in brown algae: Light and ammonium sensitivity in Laminaria digitata is absent in Fucus species

Fucus and Laminaria species, dominant seaweeds in the intertidal and subtidal zones of the temperate North Atlantic, experience tidal cycles that are not synchronized with light:dark (L:D) cycles. To investigate how nutrient assimilation is affected by light cycles, the activity of nitrate reductase (NR) was examined in thalli incubated in outdoor tanks with flowing seawater and natural L:D cycles. NR activity in Laminaria digitata (Huds.) Lamour. showed strong diel patterns with low activities in darkness and peak activities near midday. This diel pattern was controlled by light but not by a circadian rhythm. In contrast, there was no diel variation in NR activity in Fucus serratus L., F. vesiculosus (L.) Lamour., and F. spiralis L. either collected directly from the shore or maintained in the outdoor tanks. In laboratory cultures, transfer to continuous darkness suppressed NR activity in L. digitata, but not in F. vesiculosus; continuous light increased NR activity in L. digitata but decreased activity in F. vesiculosus. Furthermore, 4 d enrichment with ammonium (50 mu mol . L-1 pulses), resulted in NR activity declining by > 80% in L. digitata, but no significant changes in F. serratus. Seasonal differences in maximum NR activity were present in both genera with activities highest in late winter and lowest in summer. This is the first report of NR activity in any alga that is not strongly regulated by light and ammonium. Because light and tidal emersion do not always coincide, Fucus species may have lost the regulation of NR by light that has been observed in other algae and higher plants.

Seasonal differences in the effects of oscillatory and uni-directional flow on the growth and nitrate-uptake rates of juvenile Laminaria digitata (Phaeophyceae)

The influence of oscillatory versus unidirectional flow on the growth and nitrate-uptake rates of juvenile kelp, Laminaria digitata, was determined seasonally in experimental treatments that simulated as closely as possible natural environmental conditions. In winter, regardless of flow condition (oscillatory and unidirectional) or water velocity, no influence of water motion was observed on the growth rate of L. digitata. In summer, when ambient nitrate concentrations were low, increased water motion enhanced macroalgal growth, which is assumed to be related to an increase in the rate of supply of nutrients to the blade surface. Nitrate-uptake rates were significantly influenced by water motion and season. Lowest nitrate-uptake rates were observed for velocities <5 cm · s−1 and nitrate-uptake rates increased by 20%–50% under oscillatory motion compared to unidirectional flow at the same average speed. These data further suggested that the diffusion boundary layer played a significant role in influencing nitrate-uptake rates. However, while increased nitrate-uptake in oscillatory flow was clear, this was not reflected in growth rates and further work is required to understand the disconnection of nitrate-uptake and growth by L. digitata in oscillatory flow. The data obtained support those from related field-based studies, which suggest that in summer, when insufficient nitrogen is available in the water to saturate metabolic demand, the growth rate of kelps will be influenced by water motion restricting mass transfer of nitrogen.

The influence of water motion on the growth rate of the kelp Laminaria hyperborea

The kelp Laminaria hyperborea is a dominant component of the subtidal nearshore ecosystem and is subjected to a heterogeneous wave and current climate. Water motion is known to influence physiological processes in macroalgae such as photosynthesis and nutrient uptake attributed to mass-transfer limitation. The study attempts to establish the effect of water motion on the growth rates of blades and elongation rates of the stipes of L. hyperborea at adjacent wave-exposed and wave-sheltered locations over a 12month period from field observations. The observations were supported by detailed physical and chemical measurements (light, temperature, seawater nutrient concentrations and hydrodynamics) and of tissue carbon and nitrogen concentrations together with δ¹³carbon. Despite a 30% difference in the root mean square of the velocity (Vel_rms) between the two survey locations, there was no evidence to suggest that water motion had any direct influence on the growth rates of either the blades or elongation of stipes of L. hyperborea. No significant differences were observed between either environmental or plant physiological variables between the sheltered and exposed locations. Using an integral velocity parameter (Vel_rms) the present study also highlighted the importance of the tidally induced current component of water flow in the subtidal zone. 

The influence of water motion on the growth rate of the kelp Laminaria digitata

The shallow water kelp Laminaria digitata, abundant in coastal zones of the North Atlantic, is exposed to a range of hydrodynamic environments that makes it ideal for assessing the role of water motion on their growth rate. Here we quantify the growth of L. digitata, as a factor of blade and stipe elongation, at sites adjacent to Strangford Lough, Northern Ireland under different hydrodynamic conditions over a one year period. A modelling approach was used to numerically determine both the temporal and spatial variability of the hydrodynamic environment. Ambient seawater nutrient concentrations, temperature and irradiance were measured as well as the internal nutrient status of the L. digitata populations. Kelp populations growing in the greatest and lowest water motion showed the lowest growth rates. Differences observed in growth rate could not be attributed to seawater nutrient availability, temperature or light. The internal nutrient status also suggested no influence on the observed differences in growth rate. Therefore if there are minimal differences in light, temperature and nutrients between sites, then populations of L. digitata exposed to different water motions are likely to exhibit different growth rates. It is suggested that the growth rate differences observed were a function of water motion with the possibility that, in response to the hydrodynamic forces experienced by the algal cells, L. digitata kelps in the high energy environments were putting more energy into strengthening cell walls rather than blade elongation

Laminaria ochroleuca Bachelot de la Pylaie canopy effect on intertidal understorey benthic assemblages in northern Portugal

Dissertação de mest., Biologia Marinha, Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2010

Aislamiento y caracterización de metabolitos secundarios de Bougainvillea glabra, Choisy, (Nyctaginaceae); Leucophyllum frutescens, (Berl) I. M. Johnst, (Scrophulariaceae) y Eriobotrya japonica, Linsl (Rosaceae) [por] Eduardo Alberto Martínez Vega.

Tesis (Maestría en Ciencias con Especialidad en Química de Productos Naturales) U.A.N.L.

Efeito da suplementação com retinol palmitato em codornas (Coturnix coturnx japonica) nos níveis de retinol na gema dos ovos

Vitamin A deficiency is a serious public health problem in developing countries, and it causes death and blindness among children in the developing countries. The fortification of food could be an important source of vitamins to control deficiency. 60 Coturnix coturnix japonica quails were used in a randomized design with duration of seven weeks. The birds were assigned into five treatments with four repetitions. The objective was to evaluate the influence of the supplementation with different levels of retinyl palmitate (2,000 IU, 4,000 IU, 8,000IU and 16,000 IU) in quails under the levels of retinyl in egg yolks. The method used to dose retinyl in yolks of quail eggs was High Performance Liquid Chromatography and the enzymatic method to quantify the cholesterol concentration. The weight and production of eggs was significantly modified by the supplementation with retinyl in the birds. The results showed a gradual increase in the incorporation of retinyl in the egg yolk as a response to the supplementation, reaching values 384% higher than the control values. By the end of the supplementations a significant reduction in the concentrations of retinyl in the eggs yolk was observed. The most lasting supplementations were with 8,000 IU and 16,000 IU which lasted for three weeks. The cholesterol content in eggs was not significantly modified. The consumption of one egg enriched with 16000UI of retinol palmitate in the present study, by day, would probably reach 10 and 7,3% of the daily recommendations of this micronutrient for children of 1 to 3 years of age, and for 4 to 8 years, respectively. The nutritional value of eggs, related to the vitamin A, can be improved by supplementation of quails

Avaliação Macroscópica e Morfométrica do Oviduto de Codornas (Coturnix coturnix japonica) Quando Alimentadas com Diferentes Níveis de Proteína

Foram utilizadas doze codornas domésticas, divididas em três grupos de quatro aves cada. As aves receberam rações padronizadas contendo 16%, 20% e 24% de proteína, sendo alimentadas por um período de quinze semanas, quando foram pesadas e sacrificadas imediatamente. Após a abertura da cavidade abdominal e evisceração do trato gastrointestinal, os ovários e ovidutos foram dissecados e pesados. Com o auxílio de um paquímetro mediu-se o comprimento das partes do oviduto: infundíbulo, magno, istmo, útero e vagina e avaliou-se o número de pregas do magno e do istmo. Foram realizados cortes histológicos do magno, istmo e útero onde se obteve medidas das espessuras das camadas epitelial e glandular. Os dados foram submetidos a análise de variância (ANOVA) e observou-se que não houve diferenças significativas no peso corporal, peso do ovário, do oviduto e nos comprimentos das partes do oviduto bem como no número de pregas do magno e ístmo. Verificou-se diferenças significavas na espessura da camada epitelial do istmo de aves alimentadas com 20% de proteína na ração. Além disso, houve diferenças significativas na espessura da camada glandular do magno, istmo e útero das aves alimentadas com 24% de proteína na ração em relação às aves que receberam 16% e 20% de proteína. O nível de 24% de proteína aumentou a espessura da camada glandular do magno, ístmo e útero o que poderia resultar em melhoria no peso dos ovos e na espessura da casca.

Beak trimming methods and their effect on the performance and egg quality of Japanese quails (Coturnix japonica) during lay

A total number of 720 Japanese quail females, reared under identical management conditions, and receiving feed and water ad libitum, was used. Quails were housed and reared from 1-35 days of age in litter pens in a rearing house, and then were transferred to a quail layer house. This study aimed at verifying if different beak trimming method could optimize egg production and quality by reducing stress and cannibalism among birds. A completely randomized experimental design was used, with six treatments in a 2x3 factorial arrangement, with two beak trimming ages (14 and 21 days) and three beak trimming variants (non-trimmed, 1/3 of the beak trimmed, or 1/2 of the beak trimmed), 6 replicates of 20 birds each. Performance was evaluated by feed intake, percentage of lay, egg mass, feed conversion ratio per dozen and per kg eggs, and mortality. Performance was influenced by trimming variant, with the best results obtained by birds with intact and those with 1/3 of the beak trimmed. Better specific gravity was in quails submitted to beak trimming at 21 days of age, whereas other egg quality parameters did not present significant results. Based the results obtained in the present study, it is recommended to submit to beak trimming either at 14 or 21 days of age.

Traceability of animal byproducts in quail (Coturnix coturnix japonica) tissues using carbon (13C/12C) and nitrogen (15N/14N) stable isotopes

Consistent information on meat products consumed by the public is essential. The technique of stable isotopes is a powerful tool to recover consumers' confidence, as it allows the detection of animal byproduct residues in poultry meat, particularly in quail meat. This study aimed at checking the presence of poultry byproduct mixtures in quail diets by applying the technique of carbon (13C/12C) and nitrogen (15N/14N) stable isotopes in quail breast muscle, keel, and tibia. Sixty four one-day-old male quails were obtained from a commercial farm. Birds were housed in an experimental house from one to 42 days of age, and were randomly distributed into 8 experimental treatments, and fed diets containing poultry offal meal (POM), bovine meat and bone meal (MBM) or poultry feather meal (PFM), or their mixtures. Four birds per treatment were slaughtered at 42 days of age, and breast (Pectoralis major), keel, and tibia were collected for analyses. The inclusion of animal byproducts in quail diets was detected by 13C e 15N analyses in the tissues of the birds; however, it was not possible to specify which byproducts were used. It was concluded that quail meat can be certified by the technique of stable isotopes.

Beak-trimming methods and their effect on the performance of japanese quail pullets (Coturnix japonica)

This study aimed at verifying if beak-trimming methods in Japanese quail pullets could optimize production by decreasing stress caused by cannibalism. A total number of 816 day-old Japanese quails was distributed in a completely randomized experimental design in a 2 x 3 factorial arrangement, with two beak-trimming ages (14 and 21 days of age) and three beak-trimming sizes (not trimmed, 1/3 trimmed, or 1/2 trimmed), and 4 replicates of 34 birds per replicate. Birds were submitted to the same management and feeding conditions. Weight gain, feed intake, feed conversion ratio, and mortality were evaluated. There was no significant effect of age at beak trimming on the evaluated parameters (P>0.05), as well as no significant interaction between age at beak trimming, and beak-trimming method. There was a significant effect (P<0.01) of trimming size on performance, with the best performance observed in birds not submitted to beak trimming or had 1/2 of the beak trimmed. When the beak was more aggressively trimmed (1/2), parameters were worse. According to the obtained results, it is recommended to trim 1/3 of the beaks, which can be performed either at 14 or 21 days of age.

Production performance and egg quality of quails (Coturnix japonica) during several periods of the day

Three experiments were carried out to analyze the performance and egg quality of Japanese quails throughout the day when submitted to different lighting programs. In each experiment, birds were submitted to a period of 28 days for adaptation to the lighting program. During the following three days, each day - from 7 am to 7 pm or 9 pm - was divided into six or seven periods of two hours each, and the remaining hours corresponded to another single period. All birds were submitted to the same management practices, and received water and feed ad libitum. The experimental diet was formulated according to NRC (1994) standards. It was observed lower feed intake in the period of 9 pm to 7 am, and a higher incidence of lay from 3 pm to 7 pm, as opposite to hens, which peak of egg laying occurs during the morning. Some controversial results were found among experiments as to eggshell quality during the different periods of the day. Variation on the lighting program had little influence on the other performance and egg quality parameters.