Ricardo J.G. Pereira

Annual changes in seminal variables of golden lanchead pitvipers (Bothrops insularis) maintained in captivity

Bothrops insularis is an endemic and critically endangered snake with an estimated population of 2000 individuals restricted to Queimada Grande Island, in southeastern Brazil. Brazilian researchers established a captive breeding program for the species that includes the application of assisted reproductive technologies. The present study, therefore, aimed to evaluate semen samples from captive B. insularis throughout the year to ascertain seasonal differences in semen traits as well as correlations with body size and weight. Eighteen males with snout-vent length (SVL) ranging from 43.5 to 73.7 cm were collected at quarterly basis between August 2012 and May 2013. Macroscopic analysis revealed semen volumes ranging from 0.5 to 6.0 μL with samples featuring whitish to yellowish color and creamy and thick consistency. Viable sperm was obtained from all males indicating that individuals with SVL equal to or greater than 43.5 cm are sexually developed. However, adult and immature males (estimated by SVL) exhibited different seasonal profiles for motility and progressive motility. Adult males had a decrease in sperm motility and progressive motility during summer and spring, respectively, whereas the same variables did not vary throughout the year in immature snakes. Sperm concentration in all individuals was less (0.5 × 10(9) μL) during the winter, but no seasonal fluctuations were detected in semen volume. These findings are of particular importance to the development of reproductive tools such as male selection, artificial insemination and sperm freezing for the genetic management of this critically endangered snake.

Effect of simple and low-cost enrichment items on behavioral, clinical, and productive variables of caged laying hens

ABSTRACT Housing layers in battery cages is a practice still used by many countries but it has been criticized because of its influence on behavioral repertoire of birds. We investigated whether simple and affordable enrichment devices alone impact behavior, foot condition and performance of laying hens housed in conventional cages. Hens were divided into plain cages (CON), cages with perches (PER), and cages with tassels and scratch-pads (ENR), and parameters were evaluated before and after enrichment placement. After perch placement inactivity, drinking and competition for space reduced 35.6%, 40.8% and 70.3%, respectively, whereas social interaction increased 19.3%. Both modifications decreased locomotion (75.0% and 42.4% for PER and ENR respectively) and abnormal behaviors (62.5% and 43.9.4% for PER and ENR respectively). None of the performance variables were affected by ENR or PER. Thermography was more efficient than visual inspection in detecting subclinical bumblefoot, and it confirmed that PER reduced subclinical and clinical cases. Our findings indicate that perches increased welfare-related behaviors and foot health of hens, supporting the use of these inexpensive and highly adaptable alternatives for the enrichment of battery cages.

Urofecal steroid profiles of captive Blue-fronted parrots (Amazona aestiva) with different reproductive outcomes

Despite Psitaciformes (parrots) being the third largest nonpasserine order (398 species), it currently ranks second in number of threatened species (28%) according to the Internatinal Union for Conservation of Nature (IUCN) criteria. Since most of the literature concerning reproductive endocrinology in avian species derives from domestic and song birds, it is puzzling that advances in reproductive science for the Psitaciformes order lags far behind, in spite of the growing threats against them. In order to expand our knowledge of Neotropical parrots (Psittacidae), we examined annual changes in urofecal sex steroid metabolites of Blue-fronted amazon pairs (Amazona aestiva) exhibiting successful (nestlings) and unsuccessful breeding (infertile or no eggs). Urofecal samples were collected over a year from eight breeding pairs housed under the same environmental and management conditions. Fecal androgen and progestagen concentrations were determined in males and females, respectively, by enzyme immunoassays previously validated for this species. All eggs were registered between late winter and mid-spring, and egg-laying intervals varied between females (range: 1-8 days; average 3.60 ± 0.51 days). Similar profiles of urofecal progestagens were observed in reproductively successful females and females producing infertile eggs, with progestagen peaks preceding egg laying events (1.77 ± 0.50 days). In contrast, non-laying females had no rises in progestagens during the year. Successful and unsuccessful males did not displayed distinct annual patterns of androgen production, and apart from the peaks during the breeding season, more than half of the individuals intriguingly presented significant increases from late summer to early autumn, a period without reproductive activity. Finally, we noticed that samples with progestagen levels exceeding 40 ng/g had very high probability (>97.5%) to be from females in pre-laying or laying phases, suggesting a feasible application of this characteristic to noninvasively discriminate the reproductive status in amazon females with an accuracy and sensitivity of 94.55% and 58.13%, respectively. Our findings confirmed that urofecal progestagens and androgens are good indicators of the gonadal condition in Blue-fronted amazons, but there is still much to be done for their extensive use in artificial insemination or selection of the most suitable breeding birds for the season.

Avaliação dos níveis de desgaste e de microdureza em amostras de ferro sinterizado com e sem tratamento de ferroxidação e nitretado a plasma

Nitretacao a plasma e uma tecnica de modificacao superfi-cial que objetiva melhorar propriedades mecânicas dos ma-teriais tais como a dureza, resistencia ao desgaste e resis-tencia a fadiga. Neste trabalho, este processo foi empregado na modificacao superficial de uma liga de ferro sinterizado. Foram feitos ensaios de desgaste e microdureza na liga sem tratamento e nas amostras submetidas ao tratamento de fer-roxidacao e ao tratamento a plasma realizado sob diferen-tes condicoes de tempo e temperatura. Os resultados mos-traram que tanto a resistencia ao desgaste como a microdu-reza aumentam com o tempo e a temperatura de nitretacao, sendo que a variavel que mais influenciou nas caracteristi-cas mencionadas foi a temperatura.

Effect of Temperature and Pressure on Wear Properties of Ion Nitrided AISI 316 and 409 Stainless Steels

Stainless steels are widely used in chemical and other industries due to their corrosion resistance. However, because of their low hardness and wear properties, their applications are limited. Many attempts have been made to increase the surface hardness of these materials by using plasma techniques. Plasma nitriding is distinguished by its effectiveness, and for presenting a relatively low cost and being a clean process, producing hard surface layers on stainless steels. Aiming to verify the influence of the temperature and pressure on the modified resultant layers, samples of AISI 316 and 409 stainless steels were plasma nitrided in two different temperatures (450 and 500°C) and pressures of 400, 500, and 600 Pa for 5 h. After the nitriding treatment, the layers were analyzed by means of optical microscopy and wear tests. Wear tests were conducted in a fixed-ball micro-wear machine without lubrication. After the plasma nitriding treatment on AISI 316 and 409 samples, homogeneous and continuous layers were produced and their thicknesses increased as the temperature increased and as the pressure decreased. The nitriding treatment on the AISI 316 steel resulted on the formation of expanded austenite layers at 450°C and chromium nitrides (CrN and Cr2N) phases at 500°C. The nitriding treatment on AISI 409 yielded the formation of similar layers for both treatment temperatures; these layers constituted mainly chromium (Cr2N) and iron (Fe2N, Fe3N, and Fe4N) nitrides. After the nitriding treatment, the AISI 316 steel sample presented higher wear resistance for lower temperature and pressure values. The increase on layer fragility, for higher temperature and pressure values, can be responsible for this inverse tendency. The wear resistance of the nitrided AISI 409 sample followed a logic tendency: the harder the layer, the better the performance, i.e., the performance was improved with the increase in both the temperature and pressure.