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981.
Immunization of ewes with oil emulsion toxoid followed by an aluminium phosphate-adsorbed toxoid both containing 10 Lf per dose, resulted in a very high antitoxin level in their lambs. Two injections of aluminium phosphate-adsorbed toxoid also imparted a passive immunity to lambs which is considered to be adequate to protect them against tetanus for 4 weeks after birth.  相似文献   
982.
983.
984.
Reexamination of the phenomenon of volcanic-dust sunsets, as typified by the Krakatoa event, supports a theory that the scattering layer is produced by the interaction of ozone and sulfur dioxide in much the same manner as is the normal "Junge"aerosol layer at 20 kilometers.  相似文献   
985.
Background: The potential for acid-detergent insoluble ash (ADIA), alkaline-peroxide lignin (APL), and acid-detergent lignin (ADL) to predict fecal output (FO) and dry matter digestibility (DMD) by cattle offered bermudagrass [Cynodon doctylon (L) Pers.] hays of different qualities was evaluated. Eight ruminally cannulated cows (594 ± 35.5 kg) were allocated randomly to 4 hay diets: low (L), medium low (ML), medium high (MH), and high (H) crude protein (CP) concentration (79, 111,131, and 164 g CP/kg on a DM basis, respectively). Diets were offered in 3 periods with 2 diet replicates per period and were rotated across cows between periods. Cows were individually fed 20 g DM/kg of body weight in equal feedings at 08:00 and 16:00 h for a 10-d adaptation followed by a 5-d total fecal collection. Actual DM intake (DMI), DMD, and FO were determined based on hay offered, ort, and feces excreted. These components were then analyzed for ADL, APL, and ADIA concentration to determine marker recovery and marker-based estimates of FO and DMD. Results: Forage DMI was affected by diet (P = 0.02), and DMI from MH and H was greater (P 〈 0.05) than from L. Apparent DMD tended (P = 0.08) to differ among diets while FO (P = 0.20) was not affected by diet treatments. Average ADL recovery (1.16) was greater (P 〈 0.05) than that of ADIA (1.03) and APL (1.06), but ADIA and APL did not differ (P = 0.42). Estimates of FO and DMD derived using APL and ADIA were not different (P≥0.05) from total fecal collection while those using ADL differed (P 〈 0.05). There was no diet by marker interaction (P≥ 0.22) for either FO or DMD. Conclusion: Acid-detergent insoluble ash and APL accurately predicted FO and DMD of cattle fed bermudagrass hay of varying nutrient composition. These internal markers may facilitate studies involving large numbers of animals and forages. Results from such studies may be used to develop improve  相似文献   
986.
Immunogenicity of Brucella abortus salt-extractable proteins   总被引:5,自引:0,他引:5  
The immunogenic properties of salt-extractable proteins and chromatographic fractions thereof from Brucella abortus were evaluated in lemmings (Dicrostonyx rubricatus). The efficacy of the Brucella proteins as immunogens was determined after challenge with virulent B. abortus strain 2308 and was based on protection against clinical signs and gross lesions of brucellosis, as well as on numbers of viable Brucella in the spleen. Vaccination of lemmings with as little as 0.1 microgram of salt-extractable proteins (CSP) suppressed splenic infection, resulting in reduced numbers of viable organisms per spleen of 5-6 logs compared to non-vaccinated controls. Protein fractions separated by column chromatography were generally effective in reducing splenic infection, and contained proteins with molecular weights of 30,000, 20,000 and 12,000. Vaccines containing chemically modified dodecanoyl-CSP offered no additional advantage over unmodified CSP vaccines.  相似文献   
987.
Abstract

Extract

Malignant hyperthermia is a rare and usually fatal complication of general anaesthesia. It occurs in man (Britt and Kalow, 1970 Britt, B. A. and Kalow, W. 1970. Malignant hyperthermia: a statistical review. Can. Anaesth. Soc. J., 17: 293315. [Crossref], [PubMed] [Google Scholar]) and in certain breeds of pigs, the, Landrace (Hall et al., 1966 Hall, L. W., Woolf, N., Bradley, J. W. P. and Jolly, D. W. 1966. An unusal reaction to suxamethonium chloride. Br. med. J., 3: 594594.  [Google Scholar]; Berman et at, 1970 Berman, M. C., Harrison, G. G. and Bull, A. B. 1970. Changes underlying halothane-induced malignant hyperpyrexia in Landrace pigs. Nature. Lond., 225: 653655.  [Google Scholar]; Harrison et al., 1970 Harrison, G. G., Berman, M. C., Heekman, R., Bull, A. B., Terblanche, J. and Kench, J. E. 1970. “Anaesthetic induced malignant hyperpyrexia — Some observations of the syndrome in Landrace pigs”. In Ill Asian Australasian Congress of Anesthesiology, Canberra. Butterworths 158166.  [Google Scholar]) the Poland China (Jones et al., 1972 Jones, E. W., Nelson, T. E., Anderson, I. L., Kerr, D. D. and Burnap, T. K. 1972. Malignant hyperthermia in swine. Anesthesiology, 36: 4251.  [Google Scholar]), the Pietrain (Allen et al., 1970 Allen, W. M., Harding, J. D. J. and Paterson, D. S. P. 1970. Experimentally induced acute stress syndrome in Pietrain pigs. Vet. Rec., 87: 6469.  [Google Scholar]) and the Large White (Mawdesley-Thomas, 1969 Mawdesley-Thomas, L. E. 1969. Cited by Allen, W. M. et al. (1970) [Google Scholar]).  相似文献   
988.
989.
Anti-nutritional factors such as PHA-lectins (phytohaemagglutinin) in piglet diets can compromise piglet's performance and health by gut damage, which is especially important at weaning. Two trials were conducted to investigate the effect of PHA and fermentable carbohydrates on performance, gut morphology, physiology and microbiology in piglets weaned at 26 days.

We studied dietary PHA as a model to standardize gut damage and its effect on intestinal morphology and microbiology in piglets until 2 weeks post weaning. In general, significant lower values were observed on day 7 compared to day 14 post weaning (d7 vs. d14: 358 vs. 442 μm villus height; 42.1 vs. 108.7 U/g protein sucrase-isomaltase), indicating gut maturation. We observed very few changes between day of weaning to day 7 post weaning, lactobacilli counts being most affected (8.9, 6.9, 7.4 cfu/g for d0, d7, d14). Apart from these marked time effects the effect of PHA was negligible and thus a less suitable model to standardize gut damage in this setup.

Furthermore we studied the effect of PHA in combination with rapid or slow fermentable carbohydrates (CHO) on performance and physiological parameters. We observed a dramatic effect on performance (ADG g/d: 245 no PHA + low CHO, 111 PHA + low CHO, 132 PHA + rapid CHO, 105 PHA + slow CHO), which was less clearly reflected in the physiological parameters.  相似文献   

990.
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