Lack of influence of nursery temperature on the response of weanling pigs to supplemental vitamins C and E     

E T Kornegay  J B Meldrum  G Schurig  M D Lindemann  F C Gwazdauskas 《Journal of animal science》1986,63(2):484-491

Three trials using 240 weanling pigs were conducted during winter months to determine the influence of nursery temperature ("comfortable" vs "cold") on the response of weanling pigs to added vitamin C (700 ppm) or E (55 IU/kg) to a corn-soybean meal diet. A "comfortable" temperature schedule (27 C initially with a weekly 2 C drop) was maintained in one nursery, with the temperature schedule in the "cold" nursery about 8 C lower. Plasma concentrations of vitamin C and vitamin E were elevated when the respective vitamins were added to the diet, but were not consistently influenced by nursery temperatures. Daily gain, daily feed intake and feed efficiency were not improved with the added C or E. Daily feed intake was increased and feed-to-gain ratios were larger for pigs housed in the "cold" nursery compared with pigs housed in the "comfortable" nursery; however, daily gains were similar in the two environments. Pigs housed in the "cold" nursery were slightly stressed, as indicated by heavier adrenal glands, but the antibody response and serum glucocorticoid concentrations were not significantly affected by either diet or temperature.  相似文献   

Genomic variations and antigenic relationships among cytopathic rotavirus strains isolated in Quebec dairy herds.   总被引：1，自引：0，他引：1       下载免费PDF全文

S Dea  D Archambault  M A Elazhary    R S Roy 《Canadian journal of veterinary research》1986,50(1):126-129

Twelve isolates of bovine rotavirus, originating from eight dairy herds in Quebec known to have frequent epizootics of diarrhea in young calves in the last five years, were successfully propagated in cell cultures. The 12 isolates produced clear-cut plaques in BSC-1 cells and, except for one isolate, agglutinated human group "O" erythrocytes to an higher titer than bovine erythrocytes. Antisera to each isolate were produced in rabbits and used to study their antigenic relationships. All the isolates shared the group-specific immunofluorescent antigen and were antigenically related as demonstrated by the seroneutralization and hemagglutination-inhibition tests. However, the relationships to the Nebraska rotavirus was quite weak in cases of two Quebec isolates. When the genomes of the various isolates were compared by polyacrylamide gel electrophoresis, at least three different reproducible fractionation patterns could be identified.  相似文献   

A review of feline serum protein electrophoresis     

Baker RJ  Valli VE 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》1986,15(4):20-25

A review of the current literature available on feline serum proteins is presented. Early studies concentrated on comparative aspects of species variations in the electrophoretic pattern. The feline electrophoretogram was divided into five basic regions: albumin, alpha-1, alpha-2, beta and gamma. Different subdivisions of these areas were recognized depending on the support medium used. Current papers have compared the relative migration distances of each globulin peak to the migration of albumin. This "Rf" value enables reliable peak identification. To date, no data exists identifying the individual proteins responsible for the peaks in the alpha and beta regions. The only feline globulin to be studied is haptolobin; however its precise location on the electrophoretic strip was not identified.  相似文献   

Glycosylated hemoglobin in dogs: precision, stability, and diagnostic utility     

Easley JR 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》1986,15(1):12-15

The precision and stability of the ion exchange chromatography assay for canine glycosylated hemoglobin (HbA(1)) were examined. The coefficient of variation (CV) of within-run replicate assays was 1.3 to 2.6%; the CV of between-run duplicate assays was 3.1%. The mean HbA(1) content in 44 healthy dogs was 7.1% (SD = 1.1%, range = 5.1-9.7%). Paired aliquots of 12 blood samples were stored at 4 degrees C and 25 degrees C, and HbA(1) was measured on the day of collection and at 3, 5, and 7 days after collection. In the blood stored at 4 degrees C, no significant increase in the HbA(1) content was seen. No significant increase in HbA(1) content was found in the blood stored at 25 degrees C after 3 days, but dramatic increases were observed after 5 and 7 days of storage. No significant difference was observed in the HbA1 content in heart blood collected 18 hours after death from 9 dogs kept at 25 degrees C. The HbA(1) content was measured in 10 hospitalized diabetic dogs. Five of the dogs had received no insulin and all 5 had elevated HbA(1) values. The other 5 dogs had received insulin for 1 to 9 months; 2 of the 5 had increased HbA(1) content. The HbA(1) content was determined periodically for 9 months in one diabetic dog and it declined from 14% to 8.2%.  相似文献   

Cytochemical properties of chicken blood cells resembling both thrombocytes and lymphocytes     

Swayne DE  Stockham SL  Johnson GS 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》1986,15(2):17-24

Generally accepted criteria were used to identify typical nucleated thrombocytes and typical small lymphocytes in chicken-blood smears subjected to modified-Wright staining. Other cells, here referred to as "intermediate cells," were difficult to classify because in some aspects they resembled thrombocytes while they also had features typical of small lymphocytes. The "intermediate cells" had small, round or oval nuclei with coarsely condensed chromatin, characteristic of both thrombocytes and small lymphocytes. In addition, "intermediate cells" had moderately abundant cytoplasmic volumes, typical of thrombocytes but blue cytoplasm lacking both granules and vacuoles, which is characteristic of small lymphocytes. It made little difference to the thrombocyte count whether these cells were classified as thrombocytes or small lymphocytes; however, this decision made a substantial difference to the lymphocyte count in some chicken-blood smears. Most "intermediate cells" (351 of 410 cells examined) were nonfluorescent after treatment with formaldehyde gas. Furthermore, most "intermediate cells" failed to acquire characteristic pigments when subjected to either Grimelius staining (179 of 204 cells examined) or periodic acid-Schiff staining (173 of 206 cells examined). Typical small lymphocytes reacted in the same way, failing to fluoresce after gaseous formaldehyde treatment (65 of 65 cells examined) and failing to react during Grimelius staining (41 of 44 cells examined) or periodic acid-Schiff staining (21 of 21 cells examined). In contrast, almost all typical thrombocytes became fluorescent in response to gaseous formaldehyde (709 of 718 cells examined) and gave positive reactions when subjected to Grimelius staining (381 of 382 cells examined) or periodic acid-Schiff staining (322 of 326 cells examined). These findings suggested that "intermediate cells" should be classified as lymphocytes in differential cell counts.  相似文献   

The concept of vector in parasitology, ecology of agents, epidemiology and epizootology     

E I Korenberg  V N Kryuchechnikov 《Folia parasitologica》1986,33(3):241-248

The concepts of "host" and "vector" are compared in application to arthropods which are capable to transmit pathogens to man and animals. The paper shows that these concepts are not identical. The function of such arthropods as hosts of microorganisms, as well as their possible importance in population ecology, epidemiology and epizootology are discussed. The system of different concepts corresponding to the tasks of these scientific disciplines is also considered.  相似文献   

The effect of some benzoyl phenylureas on the larvae of earias insulana     

J. Meisner  M. Klein  K. R. S. Ascher 《Phytoparasitica》1986,14(1):3-9

Diflubenzuron, PH 60-38, PH 6043, penfluron (PH 60-44), PH 6045, triflumuron, chlorfuazuron (IKI-7899), teflubenzuron (CME 134), XRD473 and Dowco 439 were tested for their efficacy against the larvae of the spiny bollworm,Earias insulana (Boisd.), in laboratory experiments. The compounds were incorporated at different concentrations in an artificial diet and 5-day-old larvae were introduced and grown on the treated diets until pupation and adult emergence. Teflubenzuron was active at 0.1 ppm, chlorfuazuron at 0.75 ppm and PH 60-38 at 10 ppm; triflumuron and diflubenzuron were active only at 50 ppm; all the rest of the compounds were even less active. When cotton bolls were dipped in teflubenzuron and offered to 6-day-old larvae in the laboratory, only 4% and 10% of the larvae penetrated inside the bolls treated with 50 and 25 ppm a.i., respectively, whereas 68% penetrated inside untreated bolls.  相似文献   

Spring invasion of Heterodera schachtii in sugarbeet; a simulation study     

W. Van Der Werf  R. Rabbinge  W. Heijbroek 《European journal of plant pathology / European Foundation for Plant Pathology》1986,92(1):33-42

A simulation model was developed for the spring invasion of the beet cyst nematode,Heterodera schachtii Schmidt, into sugarbeet roots, according to the state variable approach. This model describes the processes of egghatch, emergence of second stage larvae from cysts, migration to roots and penetration into roots quantitatively, using published data.In 1983 a field experiment was conducted to test this model.H. schachtii cysts were introduced at depths 6–29 cm in PVC-cylinders, buried in the soil. The rooting depth of sugarbeet seedlings, growing in these cylinders, was limited to 5 cm by 50 m mesh nylon gauze. Every 10 days the second stage larvae, which had penetrated into the roots of these seedlings were counted. After 50 days, about 40% of the eggs had hatched. More than 20% of the emerged larvae penetrated if the cysts had been buried undeeply, and only 4% if the cysts had been buried at 29 cm depth.The model predicted the course of penetration into the root during the first 40 days with reasonable accuracy (r²=0.79), but in the 5th period of 10 days the model made an overestimation of more than 100%. Egghatch after 50 days was correctly simulated. The differences in penetration into the root between the model and the experiment might result from an oversimplified simulation of the penetration success or the neglection of mortality of second stage larvae. Detailed experiments should be done to provide better parameters for these factors.Samenvatting Volgens de toestandsvariabele-benadering werd een simulatiemodel ontwikkeld van de voorjaarspenetratie van het bietecystenaaltje. Het model beschrijft aan de hand van literatuurgegevens het uikomen van de eieren, het verlaten van de cyst door de larven, de migratie naar en de penetratie in de wortel.In 1983 werd een veldproef uitgevoerd om het model te toetsen. Cysten vanH. schachtii werden op 5 dieptes tussen 6 en 29 cm ingegraven in PVC-cylinders, welke waren verzonken in de bodem. De bewortelingsdiepte van de suikerbiete-zaailingen die hierin groeiden werd beperkt tot 5 cm door nylon gaas van 50 m maaswijdte. Elke 10 dagen werden de larven geteld die in de wortels van deze plantjes waren gepenetreerd. Na 50 dagen was 40% van de eieren uitgekomen. Meer dan 20% van de gelokte larven penetreerden als de cysten ondiep waren ingegraven, en slechts 4% als de cysten op 29 cm diepte waren ingegraven.Gedurende de eerste 40 dagen werd het verloop van de penetratie in de wortel met redelijke nauwkeurigheid door het model voorspeld (r²=0.79). In de 5e periode van 10 dagen maakte het model echter een overschatting van meer dan 100%. Het uitkomen van de eieren werd correct gesimuleerd. De verschillen in penetratie tussen het model en de proef zouden het gevolg kunnen zijn van een oververeenvoudigde simulatie van het penetratiesucces of van het verwaarlozen van de mortaliteit van de migrerende larven. Betere gegevens hierover zullen moeten komen uit detailproeven.  相似文献   

Dispute over Soviet Testing Heats Up     

Smith RJ 《Science (New York, N.Y.)》1985,228(4703):1072

  相似文献   

What makes a good computer device?     

Keyes RW 《Science (New York, N.Y.)》1985,230(4722):138-144

Numerous development projects aimed at replacing the silicon technology that dominates computer logic with a faster alternative have been conducted throughout the past 25 years. None has succeeded. The alternatives are usually based on a device that switches very rapidly, and they neglect many other requirements of computer logic. In this article the essential physical factors that account for the success of transistors in digital applications are identified, as are the factors that are absent in proposed alternative devices.  相似文献