Comparison of density gradient and single layer centrifugation of stallion spermatozoa: Yield,motility and survival     

J. M. Morrell  A‐M. Dalin  H. Rodriguez‐Martinez 《Equine veterinary journal》2009,41(1):53-58

Reasons for performing study: A new, simpler, technique of colloidal centrifugation has recently been developed, designated single layer centrifugation (SLC). This technique requires evaluation by comparison with a density gradient for its ability to select the best quality spermatozoa and its practicality of use on studfarms. Objective: To compare the effect of 2 methods of colloidal centrifugation, density gradient centrifugation and single layer centrifugation, on stallion sperm motility, yield and survival, using freshly collected extended stallion semen. Methods: Aliquots of extended stallion semen from 10 stallions (38 ejaculates) were processed by the 2 methods of colloidal centrifugation. For both uncentrifuged and centrifuged samples, sperm yield was calculated and subjective sperm motility assessed over several days to provide an estimate of sperm survival. Some stored semen samples, held at 4°C overnight, were also available for testing. Results: For fresh, extended semen, a similar recovery yield of motile spermatozoa was seen for the 2 methods of preparation for single layers and density gradients, respectively. Sperm motility and survival rate were significantly improved by colloidal centrifugation compared to unprocessed ejaculate, without any significant difference between methods (SLC vs. gradient). However, the yield was reduced by 18–20% when cold‐stored semen was used for centrifugation compared to fresh semen; and more variation between ejaculates was observed than for fresh ejaculates. Again, sperm motility and sperm survival were improved in the centrifuged sperm preparations compared to stored, unprocessed ejaculates. Potential relevance: The 2 colloid centrifugation techniques produce equivalent sperm preparations in terms of sperm quality. However, the SLC method would be more practical and convenient for use in the field.  相似文献   

Detection of Helicobacter and Campylobacter spp. from the aquatic environment of marine mammals     

Goldman CG  Matteo MJ  Loureiro JD  Degrossi J  Teves S  Heredia SR  Alvarez K  González AB  Catalano M  Boccio J  Cremaschi G  Solnick JV  Zubillaga MB 《Veterinary microbiology》2009,133(3):287-291

The mechanism by which Helicobacter species are transmitted remains unclear. To examine the possible role of environmental transmission in marine mammals, we sought the presence of Helicobacter spp. and non-Helicobacter bacteria within the order Campylobacterales in water from the aquatic environment of marine mammals, and in fish otoliths regurgitated by dolphins. Water was collected from six pools, two inhabited by dolphins and four inhabited by seals. Regurgitated otoliths were collected from the bottom of dolphins' pools. Samples were evaluated by culture, PCR and DNA sequence analysis. Sequences from dolphins' water and from regurgitated otoliths clustered with 99.8-100% homology with sequences from gastric fluids, dental plaque and saliva from dolphins living in those pools, and with 99.5% homology with H. cetorum. Sequences from seals' water clustered with 99.5% homology with a sequence amplified from a Northern sea lion (AY203900). Control PCR on source water for the pools and from otoliths dissected from feeder fish were negative. The findings of Helicobacter spp. DNA in the aquatic environment suggests that contaminated water from regurgitated fish otoliths and perhaps other tissues may play a role in Helicobacter transmission among marine mammals.  相似文献   

Short‐term intake of β‐carotene‐supplemented diets enhances ovarian function and progesterone synthesis in goats     

G. Arellano‐Rodriguez  C. A. Meza‐Herrera  R. Rodriguez‐Martinez  R. Dionisio‐Tapia  D. M. Hallford  M. Mellado  A. Gonzalez‐Bulnes 《Journal of animal physiology and animal nutrition》2009,93(6):710-715

The effect of β‐carotene supplementation upon luteal activity, measured as number (CLT) and volume (VLT) of corpus luteum, and P4 synthesis in goats, was evaluated. Goats (n = 22, 34 months) were randomly assigned to one of two experimental groups: (i) β‐carotene [Beta, n = 10; body weight (BW = 44.8 ± 1.45 kg), body condition score (BCS = 3.25 ± 0.07)], and (ii) Control (Control, n = 12; BW = 45.30 ± 1.32 kg, BCS = 3.33 ± 0.06). Upon oestrus synchronization, the Beta group received 50 mg of β‐carotene per day during 35 days pre‐ and 17 days post‐ovulation. The day 4, 8, 12 and 16 post‐ovulation, blood samples were collected for quantification of serum P4 concentrations by radioimmmunoassay, and transrectal ultrasonographic scanning was performed at day 18 for evaluating CLT and VLT. Overall, CLT and VLT mean were 3.10 and 2211.1 mm³ respectively. The Beta‐goats depicted both the largest values for CLT (p = 0.07) and serum P4 levels (p = 0.05), with no differences (p = 0.53) for VLT between treatments. Results suggest a higher efficiency within the cellular‐enzymatic groups defining the steroidogenic pathways in the β‐carotene‐supplemented goats, generating a larger P4 synthesis. The last is essential for ovulation of healthy oocytes, maintenance of uterine quiescence, nourishment and survival of the embryo around implantation; all of them of paramount significance during the maternal recognition of pregnancy process.  相似文献   

Host adaptation to potato and tomato within the US−1 clonal lineage of Phytophthora infestans in Uganda and Kenya     

M. E. Vega-Sánchez  L. J. Erselius  A. M. Rodriguez  O. Bastidas  H. R. Hohl  P. S. Ojiambo  J. Mukalazi  T. Vermeulen  W. E. Fry  G. A. Forbes 《Plant pathology》2000,49(5):531-539

  相似文献   

Pharmacokinetics and bioequivalence of two suxibuzone oral dosage forms in horses     

Jaraiz  Rodriguez  San Andres  Gonzalez  & San Andres 《Journal of veterinary pharmacology and therapeutics》1999,22(4):247-254

A disposition and bioequivalence study with a suxibuzone granulated and a suxibuzone paste oral formulation was performed in horses. Suxibuzone (SBZ) is a nonsteroidal anti-inflammatory drug, which was administered to horses (n = 6) at a dosage of 19 mg/kg bwt by the oral route (p.o.) in a two period cross-over design. Suxibuzone is very rapidly transformed into its main active metabolites, phenylbutazone (PBZ) and oxyphenbutazone (OPBZ). Therefore plasma and synovial fluid concentrations of SBZ, PBZ and OPBZ were simultaneously measured by a sensitive and specific high-performance liquid chromatographic method. The pharmacokinetic parameters were determined by noncompartmental analysis. Suxibuzone could not be detected in any plasma and synovial fluid samples (< 0.04 microgram/mL). Plasma PBZ and OPBZ concentrations were detected between 30 min and 72 h after granulate and paste administration. Mean plasma concentration of PBZ peaked at 5 h (34.5 +/- 6.7 micrograms/mL) and at 7 h (38.8 +/- 8.4 micrograms/mL), and mean area under the concentration-time curve (AUC0-->LOQ) was 608.0 +/- 162.2 micrograms.h/mL and 656.6 +/- 149.7 micrograms.h/mL after granulate and paste administration, respectively. Mean plasma concentration of OPBZ increased to 5-6.7 micrograms/mL, with the maximum concentration (Cmax) appearing between 9 and 12 h after administration of both formulations. The AUCs0-->LOQ for OPBZ were also similar (141.8 +/- 48.3 micrograms.h/mL granulate vs. 171.4 +/- 45.0 micrograms.h/mL paste). It was concluded that the suxibuzone products were bioequivalent with respect to PBZ. For OPBZ, the 95% confidence intervals of the pharmacokinetic parameters were within the acceptable range of 80-125%. The paste formulation provided greater bioavailability of PBZ and OPBZ.  相似文献   

Measurement of Dynamic Dough Density and Effect of Surfactants and Flour Type on Aeration During Mixing and Gas Retention During Proofing     

Grant M. Campbell  Roberto Herrero‐Sanchez  Roman Payo‐Rodriguez  Maria Luisa Merchan 《Cereal Chemistry》2001,78(3):272-277

A new method for measuring dough densities is presented, based on weighing small dough samples in air and immersed in xylene. The method can be used to evaluate the air content of low‐density doughs and to follow the changing density of a proofing dough sample. The method is applied to evaluate the effect of flour strength and surfactant addition on dough aeration and subsequent proofing. Doughs were mixed in a high‐speed mixer from two flours, a strong breadmaking flour and a weak flour. Surfactants sodium stearoyl lactylate (SSL) and diacetyl tartrate esters of monoglyceride (DATEM) were added at three levels, and the air content, proofing dynamics, and baked loaf quality were evaluated. The air content of dough was proportional to headspace pressure in the mixer, while the strong flour occluded less air than the weak flour. Surfactants greatly improved the volume of baked loaves but appeared to have no significant effect on air incorporation during mixing. The addition of surfactants appeared to increase the rate of growth of the dough piece during proofing, possibly due to increased bubble breakup during mixing or to increased rates of mass transfer of CO₂ into bubbles during proofing.  相似文献   

Temperature and soil moisture change microbial allocation of pesticide-derived carbon     

Johannes Wirsching  Luciana Chavez Rodriguez  Franziska Ditterich  Holger Pagel  Rushan He  Marie Uksa  Christian Zwiener  Ellen Kandeler  Christian Poll 《European Journal of Soil Science》2023,74(5):e13417

  相似文献