Cobalt deficiency in sheep and diagnostic reference ranges     

RG Clark  DF Wright 《New Zealand veterinary journal》2013,61(4):265-266

Abstract

Extract

In the last 2 years, two papers have been published suggesting that current New Zealand reference criteria for diagnosing cobalt deficiency should be reviewed (Grace et al 2003), and they are conservatively high and lead to the over-diagnosis of vitamin B₁₂ deficiency and ill-thriftiness in sheep (Gruner et al 2004). The comments refer to reference ranges cited by animal health diagnostic laboratories. These reference ranges were derived from the paper by Clark et al (1989 Clark, RG, Wright, DF, Millar, KR and Rowland, JD. 1989. Reference curves to diagnose cobalt deficiency in sheep using liver and serum vitamin B₁₂ levels.. New Zealand Veterinary Journal, 37: 7–11. [Taylor &; Francis Online], [Web of Science ®] , [Google Scholar]), which reviewed data from published and unpublished weight gain response trials preceding that date. The review included all published trials in New Zealand and as many unpublished trials that the authors could obtain. They involved serum vitamin B12 data from 54 trials and liver vitamin B₁₂ data from 21 trials. It was stated that more data from trials conducted in autumn were required to reliably determine an autumn response curve. In addition, it was envisaged that as other trial data became available the reference curves could be upgraded (Clark et al 1985 Clark, RG, Wright, DF and Millar, KR. 1985. A proposed new approach and protocol to defining mineral deficiencies using reference curves. Cobalt deficiency in young sheep is used as a model.. New Zealand Veterinary Journal, 33: 1–5. [Taylor &; Francis Online], [Web of Science ®] , [Google Scholar]).  相似文献   

Vaccination of pregnant ewes against infection with Salmonella Brandenburg     

H Li  RG McFarlane  J Wagner 《New Zealand veterinary journal》2013,61(6):416-422

AIMS: To develop a challenge model for Salmonella Brandenburg infection in pregnant ewes. To compare efficacies of a live attenuated Salmonella Typhimurium mutant, a subunit preparation from a virulent S. Brandenburg isolate, and a commercial multivalent inactivated vaccine in their ability to prevent experimental S. Brandenburg infection. To assess the efficacy of the live attenuated S. Typhimurium mutant against natural S. Brandenburg infection in lambs.

METHODS: Two-year-old ewes were immunised with either a live attenuated vaccine (eye-drop; n=20), a subunit vaccine (n=20) or an inactivated bacterin vaccine (n=20), both administered subcutaneously, or served as unvaccinated controls (n=21). Four weeks later, the sensitising regime was repeated as a booster vaccination, and the ewes were challenged 6 weeks later with a virulent S. Brandenburg isolate, approximately 6 weeks prior to lambing. The presence of clinical signs, abortion or death was noted following challenge. The presence and number of Salmonella spp in faecal samples taken throughout the trial, and in organs collected post mortem, were determined using an enrichment selection procedure, and confirmed by serology and pulsed-field gel electrophoresis (PFGE). Half of the surviving lambs were vaccinated with the live attenuated vaccine and all (n=39) were exposed to natural infection from contaminated pasture.

RESULTS: There was no significant protection against mortality and abortion following vaccination with the live attenuated, subunit and inactivated vaccines following experimental challenge with S. Brandenburg. There was a significant but transient decrease in the number of ewes shedding S. Brandenburg (live attenuated, p=0.05; subunit, p=0.05; inactivated, p=0.01), and in the quantity of these bacteria in the sheep from the vaccinated groups (p<0.05) compared with controls, 6 weeks after challenge. Lambs from the challenged ewes did not shed Salmonella spp after being vaccinated with the live attenuated vaccine, in contrast to some of the controls, when grazed on pasture contaminated with S. Brandenburg.

CONCLUSIONS: The use of live attenuated, subunit and inactivated vaccines did not significantly protect sheep against lethal experimental challenge with S. Brandenburg.  相似文献   

Ground-based near-infrared imaging observations of venus during the galileo encounter     

Crisp D  McMuldroch S  Stephens SK  Sinton WM  Ragent B  Hodapp KW  Probst RG  Doyle LR  Allen DA  Elias J 《Science (New York, N.Y.)》1991,253(5027):1538-1541

Near-infrared images of Venus, obtained from a global network of ground-based observatories during January and February 1990, document the morphology and motions of the night-side near-infrared markings before, during, and after the Galileo Venus encounter. A dark cloud extended halfway around the planet at low latitudes (>+/-40 degrees ) and persisted throughout the observing program. It had a rotation period of 5.5 +/- 0.15 days. The remainder of this latitude band was characterized by small-scale (400 to 1000 kilometers) dark and bright markings with rotation periods of 7.4 +/- 1 days. The different rotation periods for the large dark cloud and the smaller markings suggests that they are produced at different altitudes. Mid-latitudes (+/-40 degrees to 60 degrees ) were usually occupied by bright east-west bands. The highest observable latitudes (+/-60 degrees to 70 degrees ) were always dark and featureless, indicating greater cloud opacity. Maps of the water vapor distribution show no evidence for large horizontal gradients in the lower atmosphere of Venus.  相似文献   

Vertical Flux of Biogenic Carbon in the Ocean: Is There Food Web Control?     

RB Rivkin  L Legendre  D Deibel  JE Tremblay  B Klein  K Crocker  S Roy  N Silverberg  C Lovejoy  F Mesple  N Romero  MR Anderson  P Matthews  C Savenkoff  A Vezina  JC Therriault  J Wesson  C Berube  RG Ingram 《Science (New York, N.Y.)》1996,272(5265):1163-1166

Models of biogenic carbon (BC) flux assume that short herbivorous food chains lead to high export, whereas complex microbial or omnivorous food webs lead to recycling and low export, and that export of BC from the euphotic zone equals new production (NP). In the Gulf of St. Lawrence, particulate organic carbon fluxes were similar during the spring phytoplankton bloom, when herbivory dominated, and during nonbloom conditions, when microbial and omnivorous food webs dominated. In contrast, NP was 1.2 to 161 times greater during the bloom than after it. Thus, neither food web structure nor NP can predict the magnitude or patterns of BC export, particularly on time scales over which the ocean is in nonequilibrium conditions.  相似文献   

Effects of rectilinear acceleration and optokinetic and caloric stimulations in space     

R von Baumgarten  A Benson  A Berthoz  T Brandt  U Brand  W Bruzek  J Dichgans  J Kass  T Probst  H Scherer 《Science (New York, N.Y.)》1984,225(4658):208-212

During the flight of Spacelab 1 the crew performed a number of experiments to explore changes in vestibular function and visual-vestibular interactions on exposure to microgravity. Measurements were made on the threshold for detection of linear oscillation, vestibulo-ocular reflexes elicited by angular and linear movements, oculomotor and posture responses to optokinetic stimulations, and responses to caloric stimulation. Tests were also conducted on the ground, during the 4 months before and on days 1 to 6 after flight. The most significant result was that caloric mystagmus of the same direction as on the earth could also be evoked in the weightless environment.  相似文献   

Dietary Fat Supplementation and the Consequences for Oocyte and Embryo Quality: Hype or Significant Benefit for Dairy Cow Reproduction?     

JLMR Leroy  RG Sturmey  V Van Hoeck  J De Bie  PJ McKeegan  PEJ Bols 《Reproduction in domestic animals》2014,49(3):353-361

In many countries, fat supplementation in the diet has become common in the dairy industry. There are several ideas as to how dietary fat could influence reproductive performance. Saturated fatty acids, such as palm oil, can increase milk yield but may aggravate negative energy balance and thus may impair fertility when fed during the first week post‐partum. However, priming the lipid oxidation in the liver by feeding saturated fats during the dry period has recently been shown to be a potentially promising strategy to mitigate fat mobilization and liver accumulation post‐partum. Furthermore, polyunsaturated fats (omega‐3 fatty acids and conjugated linoleic acids) are fed to reduce the ‘de novo’ fat synthesis in the udder and thus the milk fat content, which may be of modest benefit for overall energy balance. Furthermore, omega‐6 and omega‐3 polyunsaturated fatty acids are reported to alter follicular growth, steroid synthesis and prostaglandin metabolism in the ovary and endometrium, respectively. Omega‐6 fatty acids are believed to have pro‐inflammatory and thus PGF2α‐stimulating properties rendering them extra value as ‘nutraceutical’ early post‐partum, while omega‐3 fatty acids can weaken this inflammatory potency, leading to a higher chance of survival of the embryo when supplemented during the periconceptual period. Unfortunately, research results rarely provide a consensus in this perspective. The consequences of these fat‐feeding strategies on oocyte and embryo quality remain an intriguing issue for debate. Fat feeding may alter the microenvironment of the growing and maturing oocyte of the early and older embryo and thus may affect reproductive outcome. We recently reported that dietary‐induced hyperlipidaemic conditions can be harmful for embryo development and metabolism. However, to date, research results remain somewhat conflicting most probably due to differences in fat sources used, in diet and duration of supplementation and in experimental set‐up in general.  相似文献   

Chemical immobilisation and satellite tagging of free‐living southern cassowaries     

HA Campbell  RG Dwyer  S Sullivan  D Mead  G Lauridsen 《Australian veterinary journal》2014,92(7):240-245

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Diet overlap between young-of-the-year perch, Perca fluviatilis L., and burbot, Lota lota (L.), during early life-history stages     

W. N. Probst  R. Eckmann 《Ecology of Freshwater Fish》2009,18(4):527-536

Abstract –  The diet overlap between young-of-the-year (YOY) perch and burbot in the pelagic zone of Lake Constance during spring and summer was investigated in relation to gape size limitation. Because perch were larger and grew faster than burbot during their early life history, perch overcame gape size limitation for various zooplankton taxa earlier than burbot. The interspecific diet overlap between perch and burbot decreased continuously until June, but increased slightly, when burbot became able to feed on large daphnids by the beginning of July. All zooplankton taxa could be found within perch stomachs by the middle of June, when perch overcame gape size limitation for large cladocerans. However, there was an increasing tendency for individual diet specialisation of perch, as the similarity between individual perch stomach contents decreased. In contrast, the similarity between individual burbot stomach contents remained at almost 50% until the end of August, indicating that all burbot rely on cyclopoid copepods during their entire pelagic life-history stage. Because by July YOY perch are more abundant by one order of magnitude in the pelagic zone than burbot, YOY perch may be more affected by intraspecific competition than by interspecific competition with burbot. Burbot, on the other hand, may evade strong competition with YOY perch by performing diel vertical migrations, thus being restricted to feed on migrating zooplankton prey.  相似文献   

Mid-term trends in acid precipitation,streamwater chemistry and element budgets in the strengbach catchment (Vosges Mountains,France)     

A. Probst  B. Fritz  D. Viville 《Water, air, and soil pollution》1995,79(1-4):39-59

In the Vosges Mountains (NE of France), integrated plot-catchment studies have been carried out since 1985 in the Strengbach basin to study the influence of acid atmospheric inputs on surface water quality and element budgets. In this paper, available mid-term time series (1985–1991) have been considered to detect obvious trends, if any, in surface water chemistry and element budgets. Air quality data showed a slight decline for SO₂, whereas NO₂ slightly increased over the period, but these trends are not very significant. This is in agreement with increased N concentration (mainly as NH ₄ ⁺ ) and with the stability of SO ₄ ^2? in open field precipitation. Because of a significant decrease in rainfall amount over the period, only inputs of NH ₄ ⁺ increased significantly whereas H⁺ and SO ₄ ²⁺ inputs declined. In spring and streamwaters, pH and dissolved Si concentration increased mainly as a result of a reduced flow. Na⁺, K⁺, Cl^? and HCO-3~^? concentrations remained stable whereas Ca²⁺, Mg²⁺ and SO ₄ ²⁺ concentrations declined significantly. Only NO ₃ ^? concentration increased significantly in springwaters. The catchment budgets revealed significant losses of base cations, Si and SO ₄ ^2? . These losses decreased over the period. Nitrogen was retained in the ecosystem. However, a longer record is needed to determine whether or not changes in surface water chemistry have resulted from short-term flow reductions or long-term changes in input-output ion budgets. This is specially true with N because the decline in SO ₄ ^2? output was accompanied by N accumulation.  相似文献   

Soil persistence of gungicides--experimental design, sampling, chemical analysis, and statistical evaluation     

W J Polzin  I F Brown  J A Manthey  G W Probst 《Pesticides monitoring journal》1971,4(4):209-215

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