9 EFFECT OF FLUSHING WITH PROTEIN SOURCES OF DIFFERENT DEGRADABILITY ON OVULATION NUMBER IN Santa Inês EWES

Flushing provides sheep a diet dense in nutrients before the breeding season to increase the ovulation rate and is usually accompanied by increase in body weight (BW) and body condition score (BCS). Although the effect of flushing with high-energy diets is documented, the influence of flushing with high-protein diets on ovulation rate and on plasma urea nitrogen (PUN) is not well established. The aim of this study was to evaluate the ovulation rate of Santa Ines ewes subjected to flushing with protein sources with different ruminal degradability. Forty-eight ewes were assigned to 2 treatments in a randomized block design, based on initial BCS (2.25 to 2.5; 2.75; and 3.0 to 3.25; scale 1 = thin and 5 = fat). The treatments consisted of 2 isonitrogenous (12% crude protein) and isocaloric (3.9 Mcal of metabolizable energy per day) diets, but with different proportions of rumen-degradable protein; one with soybean meal (SM, n = 24) and the other with corn gluten meal and cottonseed meal (CG + CM, n = 24), provided for 28 d before ovulation. The BW and BCS were evaluated weekly. Estrus synchronization was initiated on Day 17 after beginning the treatment diets. An intravaginal sponge with 60 mg of medroxyprogesterone acetate (MAP-60®, Tecnopec, São Paulo, Brazil) was used for 11 d, and an injection of 300 IU of eCG (Novormon®, Syntex SA, Buenos Aires, Argentina) and 50 μg of cloprostenol (Prolise®, ARSA S.R.L., Buenos Aires, Argentina) was given 9 d after beginning the protocol. Estrus was monitored twice daily. The ovulation rate was evaluated by transrectal ultrasonography and was characterized by the disappearance of dominant follicles in the ovaries. Blood samples for determination of PUN were collected on Days 7, 14, 21, and 28 after the start of flushing. Quantitative data were subjected to ANOVA and the rate of estrus detection was analyzed by chi-square test. Treatment differences were considered significant if P < 0.05. The sheep consumed the equivalent to 1.60 times the metabolizable energy requirement for maintenance and 1.86 times the requirement of protein for maintenance. Estrus detection rate (95.83 v. 83.33%), BW (3.14 ± 0.55 v. 2.94 ± 0.61 kg) and BCS (0.04 ± 0.05 v. 0.10 ± 0.06) gain before ovulation, BW (54.46 ± 1.31 v. 53.36 ± 1.44 kg) and BCS (2.78 ± 0.05 v. 2.85 ± 0.05) on the 28th experimental day, PUN (17.25 ± 0.60 v. 16.23 ± 0.66 mg dL-1), ovulation rate (2.25 ± 0.16 v. 2.24 ± 0.18) and ovulatory follicle diameter (6.61 ± 0.17 v. 6.72 ± 0.19 mm) did not differ (P > 0.05) between ewes feed SM or CG + CM, respectively. Flushing with protein sources with different ruminal degradability did not alter the ovulation rate or the ovulatory follicle diameter in Santa Ines ewes. Funded by FAPEMIG, CNPq, TECNOPEC.

A laboratory evaluation of the accuracy and precision of the photovac snapshot portable gas chromatograph and the Dräger Chip Measurement System monitor for benzene in air measurements

A laboratory evaluation of the accuracy and precision of two field instruments, the Photovac Snapshot Gas Chromatograph and the Dräger Chip Measurement System (CMS) Monitor, both capable of specific determination of benzene, was carried out. The evaluation was based on the generation of a test atmosphere of known concentration of benzene in a stainless steel calibration chamber and simultaneous sampling of the test atmosphere by each instrument. At the same time, the chamber atmosphere was continuously monitored by one or two data logging photoionization detector (PID) hydrocarbon analysers. A series of six, 10-minute charcoal tube air samples of the test atmosphere was also collected over the 1-hour run and analyzed by gas chromatography. Nine different concentrations ranging from 0.25 ppm to 8 ppm were used. Accuracy was evaluated using National Institute for Occupational Safety and Health (NIOSH) criteria. The Photovac GC consistently met the NIOSH recommended accuracy criteria of +/- 25 percent at or below 1 ppm of benzene, whereas the Drager CMS results generally fell slightly outside this criteria. Compared against less stringent accuracy criteria of +/- 35 percent, all Photovac GC results were acceptable but about 40 percent of Drager CMS results were not. The precision of Photovac GC (CV +/- 10%) is better than Drager CMS (CV = +/- 20% to 40%). Both instruments are, however, good field instruments provided their limitations are taken into account in their use.

Chloride requirement for reproduction by Pythium ultimum

Chloride (≥ 0.1 mM) was essential for asexual and sexual reproduction, but not mycelial growth, by Pythium ultimum in synthetic culture media. Bromide partially substituted for chloride in support of oogonia formation. The production of gemmae (sporangia or hyphal swellings) increased in proportion to concentrations of KCl in culture media between 0.2 and about 0.5 mM but leveled off between 0.5 and 4 mM. Chloride contents of mycelia after 3 days incubation were proportional to the number of gemmae produced when the fungus was grown in low concentrations of KCl. Under the culture conditions of this study, production of oogonia and gemmae commenced in about 70 and 95 h, respectively, in complete media. When 0.2 mM KCl was added to cultures 95 h or older that were grown in chloride deficient media, oogonium or gemma production was initiated in 20–25 or 10–17 h, respectively. Germination of gemmae, mycelial growth (gain in dry matter), and culture pH were not influenced significantly by the chloride deficiences that prevented sexual and asexual reproduction.Key words: chloride requirement, soilborne plant pathogen, reproduction of fungi, sporangia, hyphal swellings.

Elastic Behaviour of Terbium Metaphosphate Glasses Under High Pressures

The elastic and nonlinear acoustic vibrational properties of terbium metaphosphate glasses (Tb2O3)x(P2O5)1?x with x = 0�226,0�247,0�263 and 0�271 (x is the mole fraction) have been determined from measurements of the effects of temperature, hydrostatic pressure, and uniaxial stress on' ultrasonic wave velocity. At temperatures below about 140 K, the elastic stiffness of' (Tb2O3)x(P2O5)1?x glasses becomes anomalously dependent upon temperature, a behaviour usually associated with interactions between acoustic phonons and two-level systems. Except for the (Tb2O3)0�271(P205)0�729 glass, the hydrostatic pressure derivatives of the elastic stiffness and also of the bulk modulus BS of terbium metaphosphate glasses are small and negative. The third-order elastic stiffness tensor components CIJK of the (Tb2O3)0�247(P2O5)0�753 glass between 77 K and 400 K have also been determined. At room temperature, C112, C123 and C144 are positive while C111, C155 and C456 are negative. Both longitudinal and shear acoustic mode Gr�neisen parameters are small and negative: the application of pressure softens the long-wavelength acoustic phonon mode frequencies. The mode softening is enhanced as the temperature is reduced.