Variabilidade espacial de atributos físicos de um argissolo vermelho-amarelo sob pastagem e vegetação secundária em regeneração natural

This work was carried out with the objective of studying the spatial variability of the physical attributes of a Red-Yellow Ultisol under pasture and secondary vegetation in natural regeneration. Two areas were chosen in a hillside, with the soil sampling to the depth of 0-0.2 m, with the georeferenced points in a regular grid of 10x10 m, totalizing 64 points. In each point it was evaluated the total volume of porosity, macroporosity, microporosity, bulk density, soil penetration resistance and soil water content. The studied attributes in the pasture area present indicator of soil compaction for the animals' traffic, with moderate and strong structure of spatial dependence, except for the macroporosity and penetration resistance. In the area of secondary vegetation (VN) only the macroporosity does not present spatial dependence. The total volume of porosity and the bulk density present the same spatial standard in the area under pasture.

Ambiências térmica, aérea e acústica para reprodutores suínos

The swine breeder rearing environment directly affects the animal's performance. This research had the objective of developing a thermal, aerial and acoustic environmental evaluation pattern for boar housing. The experiment was carried on a commercial swine farm in Salto County -SP, Brazil. Thermal, aerial and acoustic environment data of rearing conditions were registered. Data were statistically analyzed using as threshold the ideal housing environment that leads to animal welfare. Results showed that ambient temperature was around 70% beyond normal range, while air relative humidity, air speed and gases concentration were within threshold values. Noise level data besides being within normal range did not present large variation. In relation to the fuzzy logic analysis it was possible to build up a scenario which indicated that the best welfare indexes to male swine breeders happens when thermal comfort index are close to 80%, and noise level is lower than 40 dB. In the other hand the worst welfare index occur in the sector where the thermal comfort values are below 40% at the same time that the noise level is higher than 80 dB leading to inadequate conditions to the animal, and may directly interfere in the reproduction system performance.

Thermolysed and active yeast to reduce the toxicity of aflatoxin

Aflatoxins are hepatotoxic metabolites produced by Aspergillus flavus and A. parasiticus on a number of agricultural commodities. This research was carried out to evaluate the ability of thermolysed and active Saccharomyces cerevisiae to attenuate liver damage caused by aflatoxin. Diets were prepared containing 0 aflatoxin; 400 mug kg-1 aflatoxin; 400 mug kg-1 aflatoxin plus 1% of dehydrated active yeast, and 400 mug kg-1 aflatoxin plus 1% of thermolysed yeast. A bioassay with Wistar rats was conducted for 28 days, and body organs were weighted and analyses of the liver tissue of the animals were performed. The relative weight of heart, kidneys and liver from animals submitted to the different treatments did not show any difference, and liver tissue of animals feeding on the aflatoxin-free diet was adopted as a toxicity-free pattern. Hepatic tissue of animals feeding on diets containing 400 mug kg-1 aflatoxin or the diet supplemented with 1% thermolysed yeast showed clear signs of toxicity and damage. Hepatic tissue of animals feeding on the diet containing 1% of dehydrated active yeast showed less toxicity signs and damage than those receiving the diet containing 400 mug kg-1 aflatoxin. Active, dehydrated yeast had the ability to reduce toxic effects caused by aflatoxin, but thermolysed yeast was not able to alleviate the effects of aflatoxin toxicity.

Efeito de baixas doses de radiação X em feridas suturadas e não suturadas - estudo experimental em ratos

The present work evaluated the effect of low doses of X-irradiation on the repairing process of sutured and nonsutured skin wounds in rats. For that, rats underwent a surgical proceedure, in which a 20 x 5-millimeter rectangular wound approximately 2-millimeter-deep was made in the dorsal region of each animal, and were divided in four groups: nonirradiated nonsutured; irradiated nonsutured ; nonirradiated sutured and irradiated sutured. The animals under irradiation were protected, during exposure, with a 2-millimeter-thick lead apron in such a way that only the incision was irradiated. Each animal was submitted to 18 seconds of exposure, undergoing a total of 7.4 rads. The evaluation of the effects of X-rays on the repairing process was carried out through microscopic observation by means of hematoxylin-eosin staining for morphological evaluation, and silver impregnation under polarized light for the observation of collagen synthesis. The results have shown that X-irradiation has caused delay in the repairing process, but it did not stop its development. The irradiated nonsutured group was considered to show the greater delay when compared with the other groups.

CARACTERÍSTICAS DE QUALIDADE DO CONTRAFILÉ (m. L. dorsi) DE TOUROS JOVENS DA RAÇA NELORE

Quality traits of boneless rib cut (L. dorsi muscle) from Nelore young bulls. To study the meat quality traits of Nelore breed young bulls, and the effect of age (690-780 days) on them, 113 animals were slaughtered after 109 days of intensive feeding with 20% concentrate and 80% roughage. All the carcasses were graded at the slaughter floor by the Federal Inspection and chilled for 24 hours (Tinitial=5°C, Tfinal=2°C). Fifty one half carcasses (right side), type B - B R A S I L `s grading system - from animals of 23 to 26 months were boned and separated into commercial cuts. Two steaks (2.5cm thick) were removed from each boneless rib cut (m. L. dorsi), vacuum packaged and aged for 7 days (0-2°C). The pH varied from 5.44 to 5.83 and only two samples had pH ³ 5.70. The L* (brightness) average value was 34.85. The water and fat content were 75.65% and 1.71%, respectively. The average WB shear force was 6.70kg, and it was not affected by age (690-734 days), but presented a trend (t test, p=0.22) for increasing values between 735 and 780 days. Animal age did not affect other quality traits (t test, p>0.20). It was concluded that the rib cut from Nelore young bulls may not have a good acceptability in exigent markets, and that carcasses graded B, presumed to be the best grade, do not necessarily present the best meat quality characteristics.

Gluttonous predators: how to estimate prey size when there are too many prey

Prey size is an important factor in food consumption. In studies of feeding ecology, prey items are usually measured individually using calipers or ocular micrometers. Among amphibians and reptiles, there are species that feed on large numbers of small prey items (e.g. ants, termites). This high intake makes it difficult to estimate prey size consumed by these animals. We addressed this problem by developing and evaluating a procedure for subsampling the stomach contents of such predators in order to estimate prey size. Specifically, we developed a protocol based on a bootstrap procedure to obtain a subsample with a precision error of at the most 5%, with a confidence level of at least 95%. This guideline should reduce the sampling effort and facilitate future studies on the feeding habits of amphibians and reptiles, and also provide a means of obtaining precise estimates of prey size.