Some Factors Affecting the Rate of Pregnancy after Embryo Transfer Derived from the Brazilian Jumper Horse Breed

This study aimed to evaluate the effects of certain embryo transfer parameters on the pregnancy rate after equine embryo transfer of the Brazilian Jumper Horse breed. The size, embryonic development stage, embryo quality, and synchronization of ovulation between the donor (n = 120) and recipient (n = 420) were evaluated in 396 embryos. Embryo recovery was performed on Day 6-9 after ovulation (Day 0 = day of ovulation). The recipient mares were chosen on the day of embryo recovery, and the transfers were performed that same day. The embryo size (diameter including envelopes; n = 396) ranged from 150 to 3000 μm; 67.1% measured between 400 and 1199 μm. The embryo size (400-1199 μm vs. ≤399 μm); stage of development (n = 396; blastocyst and expanded blastocyst versus compact morula and early blastocyst); quality (n = 396; grade 1 [excellent]), 2 [good], or 3 [poor]); and synchronization of ovulation between the donor and recipient (0, 1, 2, 3, and 4 days versus −1, 5, and 6 days, respectively) all affected pregnancy rate (P < .05). The pregnancy rate did not differ significantly among transfers performed on Days 0, 1, 2, 3, and 4. In conclusion, embryos measuring 400-1199 μm produced higher pregnancy rates in recipients than embryos measuring 150-399 μm, and blastocysts and expanded blastocysts produced pregnancy more efficiently than morulae and early blastocysts. The embryo quality also affected the pregnancy rate. Synchronization of donor and recipient ovulation to Days 0-4 improved the efficiency of embryo transplant.     

Optimal Management Practices for Nitrogen Application in Corn Cultivated During Summer and Fall in the Tropics

Optimal management practices for nitrogen (N) fertilization is well defined for corn (Zea mays) cultivated during summer (“summer” corn), but not for corn cultivated during the fall (“fall” corn) in the tropics. Two experiments were carried out to evaluate N rates (50, 100, 200, and 300 kg N ha^?1), N application timing (pre-planting – PP, V2–V3, and V5–V6) and N split application, once (at PP, V3, and V6), two (at V3+ V6) and three times (at PP+ V3+ V6) in corn cultivated during summer (2014/2015) and fall (2015/2016). Data on corn grain yield (CGY), weight of 1000-grains, leaf N content and values of soil-plant analyses development (SPAD) were collected and analyzed using univariate, multivariate (principal component analysis, PCA) and regression analysis. Results showed that corn growth was affected by N rates and splitting. Corn cultivated during summer presented higher CGY and weight-1000 g than corn cultivated during the fall. The highest yields were obtained with higher N rates on “summer” corn (125 kg N ha^?1) than “fall” corn (50 kg N ha^?1). Split N-application at vegetative growth stages, V3+ V6, or PP+ V2+ V6, provided higher yields for “summer” corn, while only PP application was a reliable period of N fertilization for “fall” corn. The finding is that corn cultivated during the fall presented a lower response to N and no obvious advantages to split N fertilization when compared to corn cultivated during summer. These optimal management practices for N fertilization in corn production in the tropics depend on soil water availability.     

Growth and biomass partitioning of nine provenances of Quillaja saponaria seedlings to water stress

Information on the morphological and physiological responses of seedlings to stressors, such as water stress, is required for successful early establishment of seedlings. We examined provenance variation in morphological and physiological traits of Quillaja saponaria Molina seeds from nine provenances representing a latitudinal transect across the species range in Chile. The seedlings were subjected to two water regimes (well-watered vs water restriction) in a nursery experiment, and growth, biomass, survival, and gas exchange traits were measured. As expected, well-watered seedlings exhibited a superior performance in all traits analysed. Provenance effects were significant for most of the morphological and physiological traits. In the growth and biomass analysis, the northernmost provenance showed the lowest survival, growth and dry biomass, whereas in the gas exchange analysis, the southern interior provenance showed the highest net photosynthesis, transpiration, stomatal conductance and water use efficiency. The interaction between water regimes and provenance was only significant for diameter and net photosynthesis. These results indicate that different provenances of Q. saponaria show a stable performance across different controlled drought conditions. This information is of relevance for sourcing seeds for the restoration of the species.     

Identification of fructooligosaccharides in different banana cultivars

Banana has been currently indicated as a good source of fructooligosaccharides (FOS), which are considered to be functional components of foods. However, significant differences in their amounts in bananas have been observed in the literature. This work aims to identify and quantify FOS during ripening in different banana cultivars belonging to the most common genomic groups cultivated in Brazil. Considering that these differences can be due to cultivar, stage of ripening, and the methodologies used for FOS analyses, sugar contents were analyzed by high performance anion exchange chromatography-pulsed amperometric detection (HPAEC-PAD) and gas chromatography-mass spectrometry (GC-MS). An initial screening of eight cultivars (Ouro, Nanic?o, Prata, Ma??, Mysore, Pacovan, Terra, and Figo) in a full-ripe stage showed that 1-kestose, the first member of the FOS series (amounts between 297 and 1600 microg/g of DM), was accumulated in all of them. Nystose, the second member, was detected only in Prata cultivar. Five of the cultivars were analyzed during ripening, and a strong correlation could be established with a specific sucrose level ( approximately 200 mg/g of DM), which seems to trigger the synthesis of 1-kestose (the low amounts of FOS, below the functional recommended dose, indicates that banana cannot be considered a good source of FOS).     

Nutritional Contribution of Biofloc within the Diet of Growout and Broodstock of Litopenaeus vannamei,Determined by Stable Isotopes and Fatty Acids

The relative contributions of feed sources were determined through the isotopic signal (δ¹³C and δ¹⁵N) and fatty acid profile of feed items, shrimp muscle, and eggs of Litopenaeus vannamei reared in a biofloc system. In the growout phase, the isotope analysis showed the biofloc particle size class ≥250 μm contributed 55–100%; size ≥50 < 250 μm contributed 0–22%; and artificial feed contributed 0–45%. Principal component analysis applied to fatty acid profiles showed that biofloc ≥250 μm and artificial feed were the most important items in shrimp growout. For the egg production, isotope analysis suggested that the most important feed sources according to their relative contributions were polychaetes (0–100%), followed by artemia biomass (0–86%) and semi‐moist feed (0–66%), with lower contributions from squid, mussel, and the muscle of L. vannamei broodstock that had been cultured in biofloc. In terms of fatty acids, the most important items were artemia, polychaetes, and semi‐moist feeds. This work clarified the importance of feed sources for shrimp during culture in biofloc systems and during reproduction. Analysis of stable isotopes and fatty acids can be successfully used to trace the assimilation of nutrients during the nutrition of shrimp.     

Acaricidal activity of Calea serrata (Asteraceae) on Boophilus microplus and Rhipicephalus sanguineus

Calea serrata (Asteraceae) is an endemic Southern Brazilian plant species used for religious and medicinal purposes. Previous study revealed the presence of chromenes, a class of natural compounds that possess insecticidal properties. This study reports the effect of the hexane extract from the aerial parts of this plant on egg hatchability, egg production and mortality rates of newly hatched larvae of the cattle tick Boophilus microplus. Larvae of Rhipicephalus sanguineus, the brown dog tick, received the same treatment. The extract was toxic to the eggs of B. microplus and to the larvae of both B. microplus and R. sanguineus.     

Molecular typing of sand fly species (Diptera, Psychodidae, Phlebotominae) from areas endemic for Leishmaniasis in Ecuador by PCR-RFLP of 18S ribosomal RNA gene

Surveillance of the distribution of sand fly species is important for prediction of the risk and expansion of Leishmania infection in endemic and surrounding areas. In the present study, a simple and reliable method of typing New World Lutzomyia species circulating in endemic areas in Ecuador was established by using polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) technique. PCR-RFLP of 18S ribosomal RNA (rRNA) genes with the restriction enzyme AfaI and subsequently HinfI successfully identified seven sand fly species in nine endemic areas in Ecuador. Although intraspecific genetic-diversity affecting the RFLP-patterns was detected in a species, the patterns were species specific. The method promises to be a powerful tool for the classification of New World Lutzomyia species.