Search

Abstract: Aiming to achieve the ideal time of ovum pick-up (OPU) for in vitro embryo production (IVP) in crossbred heifers, two Latin square design studies investigated the effect of ovarian follicular wave synchronization with estradiol benzoate (EB) and progestins. For each experiment, crossbred heifers stage of estrous cycle was synchronized either with a norgestomet ear implant (Experiment 1) or a progesterone intravaginal device (Experiment 2) for 7d, followed by the administration of 150μg d-cloprostenol. On Day 7, all follicles >3mm in diameter were aspirated and implants/devices were replaced by new ones. Afterwards, implant/device replacement was conducted every 14d. Each experiment had three treatment groups. In Experiment 1 (n =12), heifers in Group 2X had their follicles aspirated twice a week and those in Groups 1X and 1X-EB were submitted to OPU once a week for a period of 28d. Heifers from Group 1X-EB also received 2mg EB i.m. immediately after each OPU session. In Experiment 2 (n =11), animals from Group 0EB did not receive EB while heifers in Groups 2EB and 5EB received 2 and 5mg of EB respectively, immediately after OPU. The OPU sessions were performed once weekly for 28d. Therefore, in both experiments, four OPU sessions were performed in heifers aspirated once a week and in Experiment 1, eight OPU sessions were done in heifers aspirated twice a week. Additionally, during the 7-d period following follicular aspiration, ovarian ultrasonography examinations were conducted to measure diameter of the largest follicle and blood samples were collected for FSH quantification by RIA. In Experiment 1, all viable oocytes recovered were in vitro matured and fertilized. Results indicated that while progestin and EB altered follicular wave patterns, this treatment did not prevent establishment of follicular dominance on the ovaries of heifers during OPU at 7-d intervals. Furthermore, the proposed stage of follicular wave synchronization strategies did not improve the number and quality of the recovered oocytes, or the number of in vitro produced embryos. [Copyright &y& Elsevier]

In this study a biological nitrogen removal process using a submerged fixed-film reactor was applied to treat industrial wastewater with phenol (1g/l), a high nitrogen concentration (0. 4gN/l) and high salinity (30g/l). The process consisted of a pre-denitrification system with a down-flow-up-flow biofilter (two columns, each with an effective volume of 21l) packed with clayey schists from recycled construction material. The efficiency of the system for reducing COD, phenol concentration and total nitrogen was tested under different running conditions such as influent flow (10, 12 and 15l/d), air loading (6. 8 and 13. 6m3/m2 h) and effluent recirculation (300%, 400%, and 600%). The system demonstrated a high capacity for reducing COD concentration (95. 75±0. 72%), independently of running conditions. The aerobic column eliminated most of the phenol in the influent. Nitrogen removal took place mainly in the anoxic column, and was conditioned by the air loading in the aerated column, owing to the dependence of nitrification on the supply of oxygen. However, this process was not able to achieve a nitrogen oxidation superior to 63%, in spite of a sufficient supply of oxygen and the diluting effect of high recirculation (600%) on the phenol concentration in the influent. In spite of the limitations observed in the process of nitrification, results for the removal of total nitrogen were as high as 83%, owing to a combination of different processes for nitrogen removal. [Copyright &y& Elsevier]

Response to superovulatory, embryo yields and quality, were evaluated after increasing exposure time to exogenous progesterone during superstimulation, with or without the addition of a GnRH agonist. Thirty-four ewes from the Santa Inês breed were synchronized with an intravaginal progesterone device (CIDR). The animals were randomly divided into three groups: exposure to progesterone for 14 days (Control, n = 12); 12 h extension of progesterone exposure (12hP4 group, n = 11); and 12 h extension, associated with the administration of 25 μg of gonadorelin acetate (12hP4GnRH group, n = 11). From the 12th to the 15th day of protocol, 133 mg of pFSH were administered through eight decreasing doses. Artificial inseminations were performed 36 and 48 h after device withdrawal, using frozen/thawed semen. The number of ewes on estrus and the time to onset of estrus after withdrawing device were similar among between all groups ( P > 0.05). All groups presented high superstimulatory response (averages ranging from 14.33 to 16.18 follicles ≥4 mm) ( P > 0.05). All groups also showed a large quantity of CL (averages ranging from 11 to 12) ( P > 0.05). The longer exposure to progesterone no reduced degenerated embryo proportion (Control = 30%; 12hP4 = 7% and 12hP4GnRH = 10%; P > 0.05). The fertilization rate was significantly higher in 12hP4GnRH when compared to Control and to 12hP4 (77%, 34% and 41% respectively). These results suggest the association of longer progesterone exposure plus GnRH administration is an alternative to increase oocyte fertilization rates when fixed time insemination is used. [ABSTRACT FROM AUTHOR]

Heat is a major factor limiting the production of animals in the tropics. Sheep are well adapted to diverse ecosystems, however, temperature and relative humidity can influence animal husbandry. Therefore, this study was carried out to verify the thermoregulation in rams of six breeds (Bergamasca, Dorper, Ile de France, Hampshire Down, Santa Ines and Texel) through the evaluation of physiological traits, body measures, laser and thermographic infrared temperatures as well as testicle morphometry associated with heat tolerance. Animals were measured and weighed, coat and hair colour determined, as well as physiological traits and laser and thermographic infrared temperatures measured twice a day. Data were analyzed with the Statistical Analysis System ® . There were differences among breeds for most of the traits linked to heat tolerance, with the Santa Ines showing better adaptation to heat stress compared to other breeds. The Dorper was not significantly better than Bergamasca or Hampshire Down breeds, while Texel and Ile de France were less well adapted. Scrotal temperatures were lowest in Hampshire Down and Dorper, while highest in Texel. Temperature gradient measured by thermography identified Hampshire Down as the least heat tolerant breed. Traits linked to heat tolerance should be taken into consideration when choosing breeds for lamb production in tropical regions. [ABSTRACT FROM AUTHOR]

Abstract: Studies were conducted to characterize the effect of season of the year on testicular morphology, fresh and frozen/thawed semen quality from Curraleiro (Pé-duro) bulls in the Brazilian Central west region. Five adult, healthy bulls underwent an andrological examination and semen collection using an electroejaculator, once a month for a year. Fresh and thawed semen were evaluated for progressive sperm motility and sperm vigor, sperm morphology and acrosomal integrity. Testicular length and volume were less (P <0.05) in April than in the other months of the year. For fresh semen, the ejaculate in April had less volume and sperm concentration (P <0.05), while sperm vigor was less (P <0.05) in June, increasing in January and February. With the frozen/thawed semen, the proportion of sperm was greater (P <0.05) in April to July, decreasing from October to December. Semen collected in December had the greatest (P <0.05) proportion of major defects while that collected in February/March had the highest proportion of minor defects. The proportion of live intact sperm reduced progressively from December to April/May. The marginal influence of the time of the year on testicular biometry and fresh semen in Curraleiro bulls shows the adaptation of this breed to the environmental conditions in the region. Thus, reproduction with natural mating should be successful at any time of year. For frozen semen collection for conservation programs, the best time of year is from June to September. [Copyright &y& Elsevier]