Development of a pathogen transport model for Irish catchments using SWAT     

R. Coffey  E. Cummins  N. Bhreathnach  V.O. Flaherty  M. Cormican 《Agricultural Water Management》2010,97(1):101-111

SWAT (Soil and Water Assessment Tool) represents a dynamic catchment modelling application that can be applied to any river basin and used to quantify the impact of land management practices on water quality over a continuous period. The objective of this study is to apply the Soil and Water Assessment Tool (SWAT) to model pathogen transport, simulate management practices affecting water quality and predict pathogen loads in Irish catchments. Based on input data regarding agricultural practice, demographics and hydrological parameters for the river Fergus catchment, SWAT was run to predict concentrations of Escherichia coli. Hydrometric validation results display a very good linear relationship between observed and predicted data (Coefficient of determination R² = 0.83, Nash-Sutcliffe efficiency E = 0.78) and indicate satisfactory simulation of hydrologic processes within the catchment. To date, pathogen predictions have proved variable between observed and simulated figures. Based on recommended values for the quantification of catchment modelling accuracy, predictions for E. coli can be described as acceptable and satisfactory with R² = 0.68 and E = 0.59. Extensive monitoring is required for such simulations and the current study represents partial validation. Results suggest that although the capabilities exist to simulate pathogen transport in catchments, the capacity to accurately account for all factors that can contribute to water degradation is uncertain. The sensitivity analysis identified the bacteria partition coefficient (BACTKDDB) as the most important input parameter. In addition it reveals areas where further research is required, particularly in assessing the initial concentration of E. coli in human/animal waste. The developed model provides a tool capable of protecting water sources and human health from waterborne pathogens.  相似文献   

Effects of supplemental dietary vitamin C on quality of semen from Nile tilapia (Oreochromis niloticus) breeders          下载免费PDF全文

NLAF Sarmento  EFF Martins  DC Costa  WS Silva  CC Mattioli  MR Luz  RK Luz 《Reproduction in domestic animals》2017,52(1):144-152

The objective of this study was to evaluate the effects of vitamin C on growth and quality of semen from Oreochromis niloticus breeders. One hundred and sixty males were fed with different levels of vitamin C (0, 261, 599 and 942 mg/kg diet). The higher weight values were recorded for 599 (166 g) and 942 (175 g) mg of vitamin C/kg diet. Sperm motility, vigour and concentration were higher with 599 and 942 mg of vitamin C/kg diet. The semen volume, gonadosomatic index and plasma protein data from the last week showed a direct relationship with increasing levels of vitamin C. No changes were observed in the hepatosomatic index and blood glucose. The haematocrit and erythrocyte showed higher values estimated by equations derived at 850 and 638 mg vitamin C/kg diet, respectively. The leucocytes were inversely proportional to the increasing levels of vitamin C. After 100 days of feeding, animals fed the diet containing 942 mg vitamin C/kg diet had higher sperm motility, linearity, curvilinear velocity, straight line velocity and average path velocity (p < .05). Higher values of beat cross‐frequency were observed in broodfish fed diets containing 942 and 599 mg vitamin C/kg. The different vitamin C levels did not cause differences in straightness, lateral head displacement and sperm morphology. For Nile tilapia males on intensive rearing and handling conditions, vitamin C levels between 599 and 942 mg/kg may be used for a better performance and quality of semen.  相似文献   

Chemical Activation with a Combination of Ionomycin and Dehydroleucodine for Production of Parthenogenetic,ICSI and Cloned Bovine Embryos     

G Vichera  J Alfonso  CC Duque  MA Silvestre  F Pereyra‐Bonnet  R Fernández‐Martín  D Salamone 《Reproduction in domestic animals》2010,45(6):e306-e312

The aim of this study was to evaluate the potential of dehydroleucodine (DhL), a new drug isolated from a medicinal herb used in Argentina, for activation of bovine oocyte. Several DhL concentrations and exposure times after ionomycin (Io) treatment were tested. The optimal DhL treatment, found for parthenogenetic development, was employed to produce bovine embryos by intracytoplasmic sperm injection (ICSI) and somatic cell nuclear transfer (SCNT). The best parthenogenic embryo developments were observed with 5 μm Io for 4 min followed by 5 μm DhL concentration and after 3‐h exposure time (52.3% cleavage; 17.4% morulae; 7.3% blastocyst; n = 109). This treatment generated no significant differences with standard Io plus 6‐dimethylaminopurine (DMAP) treatment in preimplantation embryo development. In our conditions, the embryo development reached after ICSI and SCNT assisted by the DhL treatment did not differ in terms of cleavage and blastocyst development from activation with standard Io plus DMAP treatment (p > 0.05). In conclusion, DhL utilization to activate oocytes and induce development of parthenogenotes, ICSI‐embryos or SCNT‐embryos is reported here for first time.  相似文献   

Developmental changes in the regulation of plasma growth hormone concentrations in Holstein calves     

J L Sartin  R J Kemppainen  K A Cummins  D N Marple  J C Williams 《American journal of veterinary research》1991,52(9):1397-1400

A study was initiated to determine whether development of a functional ruminant digestive system was associated with alterations in plasma growth hormone (GH) concentration. Holstein bull calves were fed milk or milk with grain until studied at the age of 1 month (n = 12). Calves placed on pasture with some grain supplementation were studied at the age of 3 months (n = 6) to determine plasma GH concentration in an animal with fully developed ruminant metabolism. Blood samples were taken at 10-minute intervals for 5 hours, followed by administration of bovine GH-releasing factor (0.075 micrograms/kg of body weight) and subsequent blood sample collection for 1 hour. On the following day, a blood sample was collected via jugular cannula, clonidine (10 micrograms/kg) was administered, and blood samples were subsequently obtained. Data indicated that milk-fed calves had higher mean plasma GH concentration than did either milk/grain-fed or older calves. The difference in mean plasma GH concentration was related to higher secretory pulse amplitude. Pituitary responses to bovine GH-releasing factor did not differ among the 3 groups, but response to clonidine were greater in milk-fed calves than in calves of the other groups. These data indicate that the change from a nonruminant to a ruminant-type gastrointestinal tract, perhaps attributable to subsequent changes in metabolism, may induce changes in hypothalmic function to decrease GH concentration.  相似文献   

Neutralizing antibody responses to bluetongue and epizootic hemorrhagic disease virus serotypes in beef cattle     

R W Fulton  L J Burge  J M Cummins 《American journal of veterinary research》1989,50(5):651-654

Blood samples were obtained from sentinel beef cattle at monthly intervals, and the sera were tested for antibodies, using a bluetongue virus (BTV) immunodiffusion test (IDT) and virus-neutralization test (VNT), for 5 BTV serotypes (2, 10, 11, 13, and 17) and 2 epizootic hemorrhagic disease virus (EHDV) serotypes (1 and 2). The cattle tested were transported from Tennessee to Texas in 1984 and 1985. All cattle were seronegative by the BTV IDT at the initial bleeding in Texas in 1984 and 1985. In 1984, 16 of 40 (40%) cattle seroconverted as assessed by results of the BTV IDT. In the 16 seropositive cattle in 1984, neutralizing antibodies were detected to BTV serotypes 10 (n = 7), 11 (n = 3), and 17 (n = 11), and EHDV serotypes 1 (n = 1) and 2 (n = 7). In 1984, no cattle seroconverted to BTV-2 or BTV-13. In 1985, 10 of 36 (27.8%) cattle seroconverted as assessed by results of the IDT. Of the 10 seropositive cattle in 1985, neutralizing antibodies were detected to BTV serotypes 10 (n = 10), 11 (n = 10), 13 (n = 7), and 17 (n = 5), and EHDV serotypes 1 (n = 1) and 2 (n = 7). In 1985, no cattle seroconverted to BTV-2. Clinical diseases attributable to BTV or EHDV was not detected in these cattle in 1984 or 1985.  相似文献   

Effect of Post‐Thaw Addition of Seminal Plasma on Motility,Viability and Chromatin Integrity of Cryopreserved Donkey Jack (Equus asinus) Spermatozoa     

C Sabatini  G Mari  B Mislei  CC Love  D Panzani  F Camillo  A Rota 《Reproduction in domestic animals》2014,49(6):989-994

Pregnancy rates in donkeys after artificial insemination with cryopreserved semen are still low, compared to the horse species. Addition of autologous seminal plasma to frozen‐thawed semen appeared to improve pregnancy rates. The aims of this study were to evaluate (1) sperm motility and plasma membrane integrity after thawing (T0) and after one and 2 h (T1 and T2) of post‐thaw incubation in either 0% (SP0) or 70% (SP70) autologous seminal plasma and (2) sperm motility, plasma membrane integrity and DNA quality (%COMP‐αt) after thawing (T0) and after 2 and 4 h (T2 and T4) of post‐thaw incubation in either 0% (SP0), 5% (SP5) or 20% (SP20) homologous seminal plasma. In experiment 1, seminal plasma decreased total and progressive sperm motility and plasma membrane intact spermatozoa immediately after dilution and at all following time points (p < 0.05). In experiment 2, total and progressive motility did not differ between treatments immediately after dilution and between SP0 and SP5 at T2, while they were lower in both SP5 and SP20 than in SP0 at T4. Plasma membrane intact sperm cells did not differ between SP0 and SP5 and were lower in SP20 at all time points. DNA quality was not affected by treatment immediately after dilution and was significantly worse for SP20 after 4 h of incubation (p < 0.05). The post‐thaw addition of seminal plasma at the tested concentrations did not improve donkey frozen semen characteristics in vitro over time.  相似文献   

New Antheridiogen from the Fern Onoclea sensibilis     

Näf U  Sullivan J  Cummins M 《Science (New York, N.Y.)》1969,163(3873):1357-1358

An antheridium-inducing hormone (antheridiogen) derived from the fern species Onoclea sensibilis (Polypodiaceae) is chromatographically distinct from the native antheridiogen of Pteridium aquilinum (Polypodiaceae). It also differs from the native antheridiogens of Lygodium japonicum and Anemia phyllitidis (Schizaeaceae).  相似文献   

Viability of OPS Vitrified Sheep Embryos After Direct Transfer     

RE Green  BFS Santos  CC Sicherle  FC Landim-Alvarenga  SD Bicudo 《Reproduction in domestic animals》2009,44(3):406-410

The aim of this study was to evaluate the viability in the effect of open pulled straw (OPS) vitrification procedure of sheep embryos after direct transference. Embryos were produced in vivo and cryopreserved in slow freezing or OPS vitrification. The survival rates of cryopreserved embryos were compared to non-frozen standard pattern. In a first set of experiments, embryos at morula and blastocyst stages were dived in ethylene glycol (1.5 M) and frozen in an automatic freezer. After being thawed, they were directly or indirectly transferred to ewes recipient. A second group of embryos were drawn into OPS and plunged into liquid nitrogen after being exposed at room temperature for 1 min and 45 s in 10% EG plus 10% dimethyl sulphoxide (DMSO), then again for 30 s in 20% EG + 20% DMSO + 0.5 M sucrose. After being warmed, embryos were also directly transferred using a French mini straw as the catheter for the transplantation process or after in vitro dilution of cryoprotectants (two-step-process). No significant difference was observed among fresh, frozen or vitrified embryos on pregnancy rate (50.0%, 38.6% and 55.8%). However, when we evaluated only the direct transference, the pregnancy rate of OPS vitrified embryos was higher than that of frozen embryos (57.1% vs 34.8%) (p = 0.07). In addition, vitrified morulae had a higher pregnancy rate than the one with frozen embryos (64.0% vs 38.9%) (p = 0.07). Finally, our results indicate that OPS vitrification technique in association with direct transference improves the viability of sheep embryos with potential applications to field conditions.  相似文献   

Morphological study of the effects of the GnRH superagonist deslorelin on the canine testis and prostate gland     

Junaidi A  Williamson PE  Trigg TE  Cummins JM  Martin GB 《Reproduction in domestic animals》2009,44(5):757-763

The present study is part of a programme of research designed to evaluate the efficacy of the GnRH superagonist,deslorelin (D-Trp6-Pro9-des-Gly10-LHRH ethylamide), as a contraceptive for male dogs. Adult dogs were assigned to a completely randomized design comprising six groups of four animals. Each dog in the control group received a blank implant (placebo) and each dog in the other five groups received a 6 mg deslorelin implant. One group of deslorelin treated dogs was sacrificed on each of days 16, 26, 41, 101 and 620, and testicular and prostate tissues were collected for study by light and electron microscopy. On days 16 and 26 after implantation, we observed partial disruption of the seminiferous tubules, with early spermatids shed into the lumen. On days 41 and 101 after implantation, 90–100% of the seminiferous tubules were atrophic and aspermatogenic.On day 101 after implantation, 99% of all sections showed atrophy of the epithelium and shrinkage of epithelial height in the ductus epididymides. On days 41 and 101 after implantation, prostate tissue showed complete atrophy of the glandular epithelium (100% of sections) and an apparent increase in the relative proportion of connective tissue. At the electron microscopic level, in dogs treated with deslorelin for 41 and 101 days, the Sertoli cells were smaller and their nucleoli appeared smaller than in the control dogs. The nucleoli of the Leydig cells were atrophied and prostate glandular epithelium showed reduced epithelial height, a trophy of the nucleolus and an absence of secretory granules.Tissues collected during the recovery phase revealed a complete recovery of spermatogenesis. In conclusion, slow release implants containing deslorelin induce a striking a trophy of the testes and prostate gland by 26 days after implantation, explaining the previously reported loss of ejaculate and arrest of sperm output. At histological level,the entire process appears to be completely reversible, in accordance with data on endocrine variables and semen production.  相似文献