Studies on preweaning piglet diarrhoea

SUMMARY The aim of this study was to determine the cause and risk factors Involved in preweaning piglet diarrhoea. Faecal samples from 2380 diarrhoeic piglets, 5 to 30 days of age, were examined for enteropathogens. Isospora suls oocysts were detected in 53.8% of samples, Escherichia coll in 18.2% and rotavirus in 16.9%. I suis had the widest distribution, being present on 70.9% of 151 piggeries. The onset of diarrhoea occurred mainly between 7 and 14 days (77.5%), peaking at 10 days. Records of 4086 litters from two intensive piggeries were analysed and showed no seasonal variation or effect of sow parity on the incidence of piglet diarrhoea. I suis was the most common enteropathogen associated with diarrhoea in piglets from 5 days of age until weaning.     

Effects of dietary soybean oil concentration on growth, nutrient utilization and muscle fatty acid composition of gilthead sea bream (Sparus aurata L.)

A 309 days feeding experiment was carried out on gilthead sea bream fingerlings (initial weight 14.7±4.4 g) to evaluate effects of substitution of fish oil with soybean oil in diets on growth and sensory characteristics and muscle fatty acid composition. Duplicate groups of fish were hand fed with four isoenergetic and isonitrogenous diets (46% protein, 14% lipid and 22 MJ kg⁻¹) in which 0%, 24%, 48% or 72% of the fish oil was replaced by soybean oil. Fish fed diet 72% reached a lower final weight (324 g) than fish fed diets 0%, 24% and 48% (349, 343 and 338 g respectively). Feed intake, protein efficiency ratio, body composition and economic profitability were not influenced by the amount of soybean oil in the diets, but muscle fatty acid composition differed with diets. Panellists observed significant sensory differences between fish fed diet 0% and diet 72%. These results verified the possibility of feeding sea bream until they reached commercial weight with a 48% dietary substitution of fish oil for soybean oil.     

Post‐Warming Competence of In Vivo Matured Rabbit Oocytes Treated with Cytoskeletal Stabilization (Taxol) and Cytoskeletal Relaxant (Cytochalasin B) Before Vitrification

The aim of this study was to investigate the effect of Taxol and Cytochalasin B on the spindle, chromosome configuration and development to blastocyst stage after parthenogenesis activation of in vivo matured rabbit oocytes after vitrification. Oocytes were randomized into four groups: oocytes treated with Cytochalasin B or Taxol before vitrification, oocytes without treatment before vitrification and fresh oocytes. Oocytes were vitrified using Cryotop method, and meiotic spindle and chromosomal distribution were assessed with a confocal laser scanning microscopy. To determine oocyte competence, in vitro development of oocytes was assessed with parthenogenesis activation. There were no significant differences in the frequencies of normal spindle (33.0%, 31.0% and 32.6%, for non‐treated, Taxol‐treated and Cytochalasin B‐treated oocytes, respectively) and chromosome (48.3%, 46.6% and 34.8%, for non‐treated, Taxol‐treated oocytes and Cytochalasin B‐treated oocytes respectively) in vitrified groups, but significantly lower than those of fresh group (89.7% and 90.2%, for normal spindle and chromosome organization, respectively). No statistical differences were found in the cleavage and blastocyst development rates between non‐treated and Taxol‐treated oocytes (7.7% and 1.5% and 13.7% and 4.6%, for non‐treated and Taxol‐treated oocytes, respectively), although they were significantly lower than in the fresh group (42.3% and 32.1%, for cleavage and blastocyst development, respectively). Oocytes treated with Cytochalasin B failed to reach blastocyst stage. Normal spindle, chromosome configuration and blastocyst development of in vivo matured rabbit oocytes were damaged in vitrification, which was not improved by Taxol and Cytochalasin B pre‐treatment before vitrification. Moreover, a detrimental effect on blastocyst development of Cytochalasin B pre‐treatment before vitrification was observed.     

Influence of vegetation recovery on water erosion at short and medium-term after experimental fires in a Mediterranean shrubland

This paper reports the influence that vegetation recovery has exerted on the soil behaviour to erosion by water during both the first and eight years after experimental fires. The work was carried out at La Concordia Experimental Station (Valencia, Spain), which includes nine plots (4 m wide × 20 m long) installed on a calcareous hillside representative of Mediterranean shrubland areas. In June 1995 a set of experimental fires were carry out at two intensity levels (high and moderate) with three plots replication for each treatment. The remaining three plots were used as the control. Rain events between June 1995 to June 1996 and from June 2002 to June 2003 were monitored and their effect on soil erosion processes determined. The vegetation changes (biomass amount and plant cover) for each studied period were also assessed.     

Effect of cyclodextrin glycosyl transferase [corrected] on dough rheology and bread quality from rice flour

Gluten-free breads are usually characterized by deficient quality characteristics as compared to wheat breads. Problems related to volume and crumb texture are associated with gluten-free breads even when rice flour is used, which seems to be the best raw material for this type of bread. The potential use of cyclodextrin glycosyl transferase (CGTase) as a rice bread improver is presented. The effect of CGTase addition to rice flour on dough rheology and bread quality was investigated. In addition, an experimental design was developed to optimize the levels of CGTase, hydroxypropylmethylcellulose (HPMC), and oil. The addition of CGTase produced a reduction in the dough consistency and also in the elastic modulus. With regard to the rice bread quality, better specific volume, shape index, and crumb texture were obtained. The amount of cyclodextrins in the bread crumb was quantified to explain the action of this enzyme. The data indicate that the improving effect of the CGTase results from a combination of its hydrolyzing and cyclizing activities, the latter being responsible for the release of cyclodextrins, which have the ability to form complexes with lipids and proteins.     

Treatment of metastatic melanoma B16F10 by the flavonoids tangeretin, rutin, and diosmin

Melanoma is one of the most frequently metastasizing malignant neoplasias. This study examines an experimental model of pulmonary metastasis and the B16F10 cell subline, highly metastatic in the lung. Antimetastatic effects of the flavonoids tangeretin, rutin, and diosmin were analyzed, and at the same time an analysis of the metastatic activity of ethanol was performed, considered to be necessary because it is used as a vehicle for administering the flavonoids. Lentini's model, which complements the macroscopic evaluation of nodule numbers by using a stereoscopic microscope and image analysis at the microscopic level, was used. The greatest reduction in the number of metastatic nodules (52%) was obtained with diosmin; similarly, the percentages of implantation, growth index, and invasion index (79.40, 67.44, and 45.23%, respectively), were all compared with those of the ethanol group, considered to be an effective control group. Rutin- and tangeretin-treated groups also showed reductions of the same index compared with the ethanol group. It would seem that structural factors would better explain these results and the antimetastatic activity of each flavonoid and the respective metabolites.     

Habitat use and spatial behaviour of the endangered Southern river otter (Lontra provocax) in riparian habitats of Chile: Conservation implications

The spatial behaviour of 10 Southern river otters Lontra provocax was analysed using radio-tracking data collected in the Queule River, Southern Chile. The estimated otter density was 0.25 individuals km⁻¹. Females with cubs and adult otters displaying mating behaviours were the only social group recorded. Studied otters were solitary and observed behaviour patterns suggest an intrasexual territoriality. No home range overlap among males existed while an average of 33% and 87% home range overlapped among females and between sexes, respectively. In the situation of core areas, only one case of overlapping between an adult male and an adult female was observed. Average home range and core area lengths were 11.3 km and 0.9 km, respectively. Otters used rivers more frequently than expected, whereas they avoided small streams. Low intensity livestock farming, without canalization of watercourses and riparian vegetation extraction practices, seems compatible with the presence of Southern river otter populations since the spatial behaviour of the studied otters was not affected under these circumstances. Based on the present official reserve sizes and distribution within the country, and also the increase of variant anthropogenic land uses outside these areas that result with consequent habitat loss and deterioration, we strongly recommend considering the importance of spatial dimension in quantity and quality habitats in further conservation planning for the Southern river otter using an integrated catchment management.     

Analysis, assessment, and improvement of fertilizer distribution in pressure irrigation systems

The transformation of traditional irrigation systems into pressure irrigation networks allows water users associations to use central fertigation systems. For efficient fertigation management, however, it is essential to obtain uniform distribution of the injected fertilizer through the system and to understand the hydraulic processes that take place in the central fertigation system. This will allow users to implement strategies that improve fertilizer distribution. In this work we develop a new methodology to improve fertilizer distribution uniformity and apply it to a case study. The results show how fertilizer distribution can be improved by means of proper scheduling of irrigation deliveries. The best results are obtained when fertigating sectors operate without non-fertigating sectors and there are not intermediate irrigations without fertilizer, achieving an improvement of the fertilizer distribution of 10.5%. In addition, this work highlights the difficulties of obtaining uniform distribution of fertilizer in a centralized irrigation system when there are users that do not want to make use of it.     

Increase of the activity of phase II antioxidant enzymes in rats after a single dose of coffee

This study evaluated the acute effect of the administration of coffee brew in the activity of phase II antioxidant enzymes in the hepatic tissue of rats. A single dose of this beverage increased the activity of the enzymes SOD, CAT, and GPx; the maximum increase occurred 1 h after administration (19.1, 22.1, and 25.1%, respectively). These changes were statistically significant (p < 0.05), the response was shown to be dose-dependent (p < 0.05), and the return to basal levels took >4 h from the intervention, suggesting a long-term effect. The total antioxidant capacity of the hepatic tissue also exhibited a peak 1 h after the intervention (6.5%), but the increase was not statistically significant and the response was not dose-dependent due to the low exposure to coffee. These results indicate that coffee increases the activities of antioxidant enzymes, improving protection against oxidative stress.