Experience-based practice tips     

Carlton Gyles 《The Canadian veterinary journal. La revue veterinaire canadienne》2009,50(8):797-798

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Stormwater runoff from highways     

Hoffman  Eva J.  Latimer  James S.  Hunt  Carlton D.  Mills  Gary L.  Quinn  James G. 《Water, air, and soil pollution》1985,25(4):349-364

Water, Air, & Soil Pollution - During four rain events, stormwater runoff samples from Interstate Highway 95 in Rhode Island were collected and analyzed for petroleum hydrocarbons, 14...  相似文献   

Effects of stage of growth,irrigation frequency and gypsum treatment on CO2 exchange of lucerne (Medicago sativa L.) grown on a heavy clay soil     

D. M. Whitfield  G. C. Wright  O. A. Gyles  A. J. Taylor 《Irrigation Science》1986,7(3):169-181

Summary Effects of weekly (W) and fortnightly (F) irrigation schedules on CO₂ assimilation by lucerne grown on untreated (C) and gypsum-ameliorated (G) heavy clay soil were investigated. Leaf area limited rates of assimilation during the initial stages of regrowth, but rates of up to 9 g CO₂ m^–2 h^–1 were measured once full ground cover was achieved after approximately two weeks. High rates were maintained until the fifth week of regrowth (one week after full flower), after which there was a marked decline.During the fourth week of regrowth, afternoon rates of canopy photosynthesis under less frequent irrigation were less than those measured at similar irradiance during the morning. This was evidenced as hysteresis in the light response curves and was apparent in all treatment during the final stages of the experiment.For the first five weeks of regrowth, daytime integrals of photosynthesis were directly related to the amount of light intercepted by the crops. The mean efficiency of utilisation of light in CO₂ assimilation was 6.2 g CO₂ MJ^–1 in all treatments apart from that on untreated soil under the fortnightly irrigation regime (treatment F_C). Its mean efficiency was 5.1 g CO₂ MJ^–1. The amounts of CO₂ assimilated exceeded the growth and respiratory requirements of the above-ground components of the crops, and it was estimated that 25% and 40% of the assimilated carbon was partitioned to and retained in the roots and crowns of the weekly and fortnightly irrigated crops, respectively.Results are appraised in terms of the response of lucerne to moisture deficits. Implications for above-ground dry matter production are also discussed.  相似文献   

A case-control study of selected pathogens including verocytotoxigenic Escherichia coli in calf diarrhea on an Ontario veal farm.   总被引：1，自引：0，他引：1       下载免费PDF全文

J B Wilson  S A McEwen  R C Clarke  K E Leslie  D Waltner-Toews    C L Gyles 《Canadian journal of veterinary research》1992,56(3):184-188

A case-control study of diarrheal disease in veal calves was conducted over a three month period on a single large veal farm in southern Ontario. One hundred diarrheic calves (cases) were identified by visual examination of their feces. Each case was matched to two nondiarrhetic controls from the same room on the same day, and a fecal sample was obtained from each animal. Fecal consistency of cases and controls was observed daily for one week following sample collection. Control calves which developed diarrhea during that period were excluded from the study. Breed, sex and the date and nature of antimicrobial drugs administered to each calf were recorded. Moisture content of fecal samples was measured by weighing samples before and after oven drying. Samples were screened for verocytotoxigenic Escherichia coli (VTEC) using a Vero cell assay, for enterotoxigenic E. coli (ETEC) using an immunoblot procedure with anti-K99 monoclonal antibodies, and for Salmonella species using modified semi-solid Rappaport-Vassiliadis medium. A latex agglutination test was used to detect rotaviruses, and samples were examined for cryptosporidia using sucrose wet mounts. No VTEC were identified in cases or controls. One calf was positive for Salmonella and three were positive for ETEC. Rotaviruses were detected in four cases and four controls. A significant positive association was found between diarrhea and infection with Cryptosporidium. This study thus provided no evidence of an association between diarrhea and infection with either VTEC, ETEC, Salmonella spp. or rotaviruses in the population examined. On the other hand our results do suggest that Cryptosporidium infection may promote transient diarrheal disease in veal calves in Ontario.  相似文献   

What is your diagnosis? Abdominal mass.     

K A Hahn  W R Widmer  S K Salisbury  W W Carlton 《Journal of the American Veterinary Medical Association》1992,200(2):221-222

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Hereditary parakeratosis in shorthorn beef calves     

D W Vogt  C G Carlton  R B Miller 《American journal of veterinary research》1988,49(1):120-121

Parakeratosis was diagnosed in 9 Shorthorn beef calves over a 4-year period. When pedigrees of these calves were analyzed, familial associations were strong. Thirty-six coefficients of relationship among all possible combinations of the 9 affected calves ranged from 0.5 to 39.8% and averaged 15.6%. All affected calves were descendants of bull A. Of 9 affected calves, 6 had bull A in their paternal and maternal pedigrees. The 3 remaining affected calves had bull A in their sire's pedigree and were born to 2 full-sib dams. Seemingly, parakeratosis in this Shorthorn herd was hereditary with the mode of inheritance being that of a simple autosomal recessive.  相似文献   

Preliminary investigations of the distribution of Escherichia coli O149 in sows, piglets, and their environment     

Goswami PS  Friendship RM  Gyles CL  Poppe C  Boerlin P 《Canadian journal of veterinary research》2011,75(1):57-60

Little is known about the sources and kinetics of enterotoxigenic Escherichia coli colonization in pigs during the pre-and post-weaning period. In this study, farrowing pens, sows, and piglets were tested for the presence of E. coli O149 by real-time polymerase chain reaction (PCR) after bacterial culture pre-enrichment on 2 farms, one with a history of post-weaning diarrhea (problem farm - PF) and the other without such a history (non-problem farm - NPF). Unlike those on the PF, the sows from the NPF did not carry E. coli O149 before parturition, although they were colonized to frequencies similar to animals on the PF soon afterwards. Most piglets from the NPF were colonized within a week after birth, whereas only a small proportion of those on the PF were colonized during that period. No difference was observed in the frequency of piglet colonization at the 2 farms either at weaning or during the following week. Post-weaning diarrhea (PWD), which is caused by enterotoxigenic E. coli (ETEC), is a multifactorial disease. The presence of ETEC alone is not always sufficient for the disease to develop. Many other factors are considered to be associated with the occurrence of PWD, including feed type (1,2), feeding regimen (1,3,4), the presence of other infectious agents (3,5), weaning age, and weight (6). Weaning, which is considered to be a major physiological and psychological stress factor, is critical for the disease to occur (7). Although piglets are already colonized with ETEC before weaning (4,8), on many farms, clinical disease occurs only after weaning (1). Both sows (9,10) and the environment (6) could be possible sources of infection for piglets, but results from previous studies have not resolved this issue because of the low sensitivity of ETEC detection methods. This study provides preliminary data based on a sensitive detection method for E. coli O149 in pigs and their environment. The results demonstrate the potential of real-time PCR for future studies on this topic.  相似文献   

The growing problem of antimicrobial resistance     

Gyles C 《The Canadian veterinary journal. La revue veterinaire canadienne》2011,52(8):817-820

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Heartworm resistance     

Gyles C 《The Canadian veterinary journal. La revue veterinaire canadienne》2011,52(12):1279-1280

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Staphylococcus aureus small colony variants (SCVs) and their role in disease     

Atalla H  Gyles C  Mallard B 《Animal health research reviews / Conference of Research Workers in Animal Diseases》2011,12(1):33-45

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