Effects of uterine cervix constriction on Wistar rats

PURPOSE: To verify if uterine cerclage can induce craniosynostosis or any cranial deformity in new born Wistar rats. METHODS: One pregnant female Wistar rat underwent laparotomy on day 18 of gestation and the uterus cervix was closed with a 3-0 nylon suture to avoid delivery, that occurs normally on the 21 day. The suture was released after 48 hours beyond the normal gestation period. The female rat delivered 11 pups. Six surviving rats from the delivery (group A - constrained group). Two rats were born from another mother and in the same age were used as control group (group B - 2 nonconstrained controls) were allowed to grow. They were sacrificed 1.2 years after their birth all the eight animals. Linear measurement, routine histology and computed tomography of the skull were performed at the time of their death to evaluate the cranial asymmetries by mesurements of the anatomical landmarks of the craniofacial skeleton of the rats on the two groups and compared then. RESULTS: We did not observe statistically significant differences in any of the compared measurements (p>0.05) obtained through the morphologic and radiologic methods. Histologic examinations did not reveal any sign of premature fusion or suture imbrications. Critical decrease in longitudinal body size was noticed as the limbs too in all the animals of group A. CONCLUSION: Constriction of uterine cervix leads to fetus suffering, even death for a few animals, associated to small body size, but not to craniosynostosis.

Estudo eletrocardiográfico de equinos de salto sadios

Avaliou-se o eletrocardiograma de 100 equinos sadios praticantes de hipismo clássico modalidade salto, com idades entre 4 e 19 anos, sendo 61 machos e 39 fêmeas, com média de 516,3 kg. Observou-se frequência cardíaca média de 40,20 ±13,33 bpm, sendo o ritmo cardíaco mais freqüente o sinusal (56%). As alterações de ritmo cardíaco estiveram presentes em 38% dos animais estudados, sendo a mais presente o marcapasso migratório (22%), seguido de bloqueio atrioventricular de 2º grau (4%), bloqueio atrioventricular de 1º grau (3%), contração ventricular prematura (2%), contração atrial prematura (1%). Não se observou correlação entre as variáveis estudadas (freqüência cardíaca, ritmo e arritmias) e a capacidade atlética, a idade e o sexo. O escore cardíaco após analise estatística não diferiu entre os grupos quanto ao desempenho atlético, a faixa etária e o sexo. O escore cardíaco, nesta amostra, não se mostrou um parâmetro confiável para se predizer o futuro atlético ou o nível de treinamento do eqüino.

ENVIRONMENTAL TEMPERATURES IN FLORIDA DAIRY HOUSING

Environmental conditions in all air-conditioned barn and in evaporatively cooled sprinkler and fall and tunnel-ventilated barns are compared and recommendations for dairy barn design for hot, humid climates arc, given. Temperature Humidity Indexes (THI) observed in the air-conditioned barn were always below 72. Average THIs ill the evaporatively cooled barns during afternoon hours were seldom less than 75. The environmental conditions observed in these studies are typical for many, areas adjacent to the Gulf Coast of the United States and for tropical regions throughout the world. Providing comfortable environmental conditions for cows housed in area with hot, humid climates is difficult using only evaporative cooling and ventilation. Air-conditioning dairy housing is a possible alternative method, particularly for high value cows.

SMALL MAMMAL PREY SELECTION BY TWO OWL SPECIES IN SOUTHEASTERN BRAZIL

A variety of factors influence prey selection by predators. Because Barn Owls (Tyto alba) and Burrowing Owls (Athene cunicularia) differ in size and foraging tactics, we expected differential predation on small mammal prey. We hypothesized that the Barn Owl, all active predator, would prey on smaller and younger individuals than the Burrowing Owl, a sit-and-wait predator. We used pellet analyses to evaluate selection of small mammals by the two owls in relation to prey), species, age, and size at the Ecological Station of Itirapina, state of Sao Paulo, in southeastern Brazil. Small mammals constituted most of the prey individuals and biomass in the diet of Barn Owls. Although Burrowing Owls consumed a wider range of taxa, small mammals represented one-third of all biomass consumed. With respect. to small mammals, Barn Owls foraged selectively relative to prey species, size, and age. Burrowing Owls foraged opportunistically relative to prey species, but selectively relative to prey size and age. Barn Owls selected smaller and younger (juvenile and subadult) individuals of the delicate vesper mouse (Calomys tener) and Burrowing Owls preyed more oil larger and older (subadult only) individuals. morphology and behavior of both prey and predators may explain this differential predation. Our data suggest that the active predator feeds oil smaller and younger prey, and the sit-and-wait predator took relatively larger and older prey.