An Epidemiologic and Economic Study of Respiratory Diseases in Two Conventional Danish Swine Herds. I: Prevalence of Respiratory Lesions at Slaughter and Their Effects on Growth     

L. G. Paisley  L. Vraa-Andersen  L. Dybkjr  K. Mller  G. Christensen  J. Mousing  J. F. Agger 《Acta veterinaria Scandinavica》1993,34(4):319

A total of 578 slaughter pigs from 2 Danish conventional farrow-to-finish operations (Herds A and B) were followed from an age of 14 days to slaughter. Pigs were weighed at 3 weeks intervals and at slaughter and an extended post mortem examination of the plucks was done. Comparison of growth rates in pigs with and without specific types of lesions by the t-test and those with multiple lesions with regression models demonstrated that Mycoplasma-like pneumonia, complicated pneumonia, anterio-ventral pleuritis, fissures and atrophic rhinitis significantly reduced mean daily gain and increased the time required to reach slaughter weight. The total impact of the lesions in Herd A was an estimated reduction in mean daily gain of 27 grams and a 2 day increase in the interval from 14 days of age until slaughter (MDG14). Decreases in MDG14 in Herd B were more substantial, 98 grams and 16.7 days. Reductions in mean daily gains during the interval from the fourth weighing until slaughter were 31 grams in Herd A and 137 grams in Herd B. Chronic dorso-caudal and parietal pleuritis, without other lesions present, had no significant adverse effects on growth rates in either herd. Interactions between lesions did not significantly alter the estimates. The R² values obtained for the regression models showed that the presence, absence or extent of lesions at slaughter explained only 13-27% of the variations in growth rates in the 2 herds.  相似文献   

Fermentation of dietary fibre in the intestinal tract of rats — a comparison of flours with different extraction rates from six cereals     

Margareta Nyman  Nils-Georg Asp  Birthe Pedersen  Bjøorn O. Eggum 《Journal of Cereal Science》1985,3(3):207-219

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Pasteurella haemolytica A1 and Bovine Respiratory Disease: Pathogenesis     

Laurence O. Whiteley DVM  PhD    Samuel K. Maheswaran BVSc  PhD    Douglas J. Weiss DVM  PhD    Trevor R. Ames DVM  MS  Mathur S. Kannan BVSc  PhD 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》1992,6(1):11-22

The severe fibrinonecrotic pneumonia associated with pneumonic pasteurellosis usually results from colonization of the lower respiratory tract by Pasteurella haemolytica biotype A, serotype 1(A1). Despite recent research efforts, the authors lack a detailed understanding of the interactions and host response to P. haemolytica in the respiratory tract. The authors hypothesize that management and environmental stress factors or viral infection alters the upper respiratory tract (URT) epithelium allowing P. haemolytica to colonize the epithelium. Once the URT is colonized, large numbers of organisms enter the lung where they interact with alveolar macrophages. Endotoxin, released from the bacteria, crosses the alveolar wall where it activates pulmonary intravascular macrophages, endothelium, neutrophils, lymphocytes, platelets, complement, and Hageman factor leading to complex interactions of cells and mediators. It is the progression of this inflammatory response with neutrophil influx that is ultimately responsible for the pulmonary injury. Leukotoxin is a major virulence factor of P. haemolytica that allows it to survive by destroying phagocytic cells. At subcytolytic concentrations it may also enhance the inflammatory response by activating cells to produce mediators and release reactive oxygen metabolites and proteases.  相似文献   

Specificity of the carbon immunoassay (CIA) test for the diagnosis of Toxoplasma infections.     

M Chinchilla  L Reyes  O M Guerrero  F Hernández 《Veterinary parasitology》1992,44(3-4):315-320

A rapid and low cost procedure, the carbon immunoassay (CIA) test, was evaluated for the diagnosis of Toxoplasma gondii infections. Using a closely related parasite (Besnoitia jellisoni) as antigen, and homologous or heterologous immune sera, it was demonstrated by light and electron microscopy that CIA is a very reliable and specific test. As it is neither expensive nor time-consuming, it can be recommended for general and routine laboratory use.  相似文献   

Effects of Pasteurella haemolytica A1 leukotoxin on bovine neutrophils: degranulation and generation of oxygen-derived free radicals.     

S K Maheswaran  D J Weiss  M S Kannan  E L Townsend  K R Reddy  L O Whiteley  S Srikumaran 《Veterinary immunology and immunopathology》1992,33(1-2):51-68

To further define the role of Pasteurella haemolytica A1 leukotoxin in the pathogenesis of bovine pneumonic pasteurellosis, its in vitro effects on bovine neutrophils were investigated. Leukotoxin-containing culture supernatant, from P. haemolytica, stimulated a neutrophil respiratory burst as measured by the generation of oxygen-derived free radicals O2- and H2O2. This effect was immediate because preincubation of neutrophils with the culture supernatant for 5 min or longer substantially suppressed this respiratory burst. This suppression was due to cytolysis of the neutrophils. Prolonged incubation of neutrophils with the same culture supernatant caused further cytolysis and degranulation. Heat-inactivated P. haemolytica culture supernatant that had lost its cytotoxic properties failed to stimulate respiratory burst by neutrophils. Furthermore, the respiratory burst, cytolysis and degranulation were abrogated only by leukotoxin-neutralizing monoclonal and polyclonal antibodies, but not by antibodies against the lipopolysaccharide. These studies show that the leukotoxin component in the culture supernatant was responsible for the generation of oxygen-derived free radicals and proteolytic enzymes from neutrophils which may participate in direct lung injury.  相似文献   

Differences in Reproductive Performance, Embryo Development, Interferon-tau Secretion by the Conceptus and Luteal Function in Ewe Lambs Synchronized in Oestrus before or after the Spontaneous Onset of Luteal Activity Preceding Puberty     

JA Abecia  F Forcada  & O Zúñiga 《Reproduction in domestic animals》2001,36(2):73-77

In mid-September, 1 month before the insertion of intravaginal pessaries to induce sexual activity, blood samples were collected every 4 days from 16 ewe lambs aged 7 months, in order to determine the incidence of ovulations by measurement of plasma progesterone concentrations. It has been studied whether the response to a progestagen treatment of ewe lambs apparently close to puberty could be modified by the onset of the ovarian events preceding puberty. The effect of the presence or absence of ovulations prior to progestagen treatment on the potential reproductive performance (fertility, litter size and fecundity), embryo development [embryo quality and interferon-tau (IFNτ) secretion], luteal function (progesterone secretion in vitro ) and endometrial progesterone content was studied in seven ovulating (Ov+) and nine nonovulating ewe lambs (Ov−) on day 14 after mating. The best potential reproductive results were obtained with Ov+ animals, although these differences could not be initially attributed to either different progesterone secretion in vitro or concentration of endometrial progesterone. Irrespective of the experimental groups, secretion of progesterone by luteal tissue from ewe lambs with normal embryos was significantly greater (p<0.05) than that of animals with abnormal embryos or with no embryos. Normal embryos secreted a higher amount of IFN-τ than those embryos classified as abnormal (p<0.07). In conclusion, ewe lambs which exhibit luteal activity before puberty have the highest levels of reproductive performances after a progestagen treatment. Corpora lutea from ewe lambs with normal embryos had higher rates of progesterone secretion in vitro and their embryos had a higher IFN-τ production by the embryos, indicating greater capacity for subsequent development.  相似文献   

Control of Johne's disease in four commercial dairy herds in Iowa     

C O Thoen  L A Moore 《Journal of veterinary diagnostic investigation》1989,1(3):223-226

A 6-year study was conducted in 4 dairy herds in Iowa in which Johne's disease was diagnosed previously. Fecal specimens were collected at 6-month intervals from animals 2 years of age and over for mycobacteriologic examination. Serum samples were obtained at 3-month intervals and tested by enzyme-linked immunosorbent assay (ELISA). The antigen used in the ELISA was a potassium chloride extract of a field strain of Mycobacterium paratuberculosis. The ELISA reactions were observed in 87% of the cows from which M. paratuberculosis was isolated. Dairy producers that participated in the Johne's control program reported reduced economic losses. Increased income was attributed to improved milk production, increased value of vaccinated animals sold as replacements to other dairy herds in which Johne's disease had been diagnosed, and the increased market value of slaughter animals removed from the herd.  相似文献   

Susceptibility to onion-induced hemolysis in dogs with hereditary high erythrocyte reduced glutathione and potassium concentrations.     

O Yamoto  Y Maede 《American journal of veterinary research》1992,53(1):134-137

The hemolytic effect of onion consumption in dogs with hereditary high erythrocyte reduced glutathione and potassium concentrations (designated HK dogs) was compared with that in clinically normal dogs. Twelve hours after oral administration of boiled onions (200 g/dog), hemoglobin concentration decreased to 84.4% of the initial value in HK dogs; it decreased only to 90.5% in clinically normal dogs. At 24 hours, methemoglobin concentration was significantly (P less than 0.05) higher in HK dogs than in clinically normal dogs. The concentration of erythrocyte oxidized glutathione increased about fivefold at 10 hours in HK dogs, whereas it did not change during the experimental period in clinically normal dogs. In addition, at 12 hours, the proportion of erythrocytes containing Heinz bodies increased to 24.4% in HK dogs, but increased only to 1.2% in clinically normal dogs. Thus, results indicated that HK dogs were more susceptible to the oxidant action of onions than were clinically normal dogs.  相似文献   

Effect of feeding high-oleic-acid peanuts to growing-finishing swine on resulting carcass fatty acid profile and on carcass and meat quality characteristics.     

R O Myer  D D Johnson  D A Knauft  D W Gorbet  J H Brendemuhl  W R Walker 《Journal of animal science》1992,70(12):3734-3741

A high-oleic-acid peanut breeding line was used in a study designed to determine the effects of feeding swine diets containing elevated levels of monounsaturated fatty acids as a means to increase the level of monounsaturates and total unsaturates in the resulting carcass fat. Forty-eight pigs were allotted to four treatments that consisted of corn-soybean meal diets that contained 1) high-oleic peanuts (HOP), 2) regular commercial peanuts (RP), or 3) canola oil (CO), each added at a dietary level to provide 10% added fat/oil, and 4) a control diet with no added fat/oil. The oil of HOP averaged 75% oleic acid vs 60% for CO and 53% for RP. The pigs were fed the experimental diets from 33 to 102 kg BW, after which all pigs were slaughtered. All three dietary oil sources resulted in increases (P < .01) of monounsaturates in the backfat; the HOP diet resulted in the greatest increase (32% greater than control). Both CO and RP increased (P < .01) the level of polyunsaturates by nearly twofold; HOP resulted in a small decrease. Total unsaturates increased (P < .01) by 24, 24, and 27% for HOP, RP, and CO treatments, respectively, over that obtained from the control treatment. Carcass fat was softer/oilier (P < .05) from pigs fed CO and RP diets, but not from those fed HOP diets, compared with carcass fat of pigs fed the control diet. Dietary fat/oil source had no effect (P > .05) on other carcass compositional traits and various meat quality attributes.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

Differentiation of hog cholera and bovine virus diarrhoea viruses in pigs using monoclonal antibodies     

Y Zhou  V Moennig  C O Coulibaly  J Dahle  B Liess 《Zentralblatt für Veterin?rmedizin. Reihe B. Journal of veterinary medicine. Series B》1989,36(1):76-80

Monoclonal antibodies against hog cholera and bovine viral diarrhoea viruses were assayed on organ tissue sections of experimentally infected animals. The animals had been infected simultaneously with both viruses. The antibodies were tested using an indirect immunofluorescence test and an indirect enzyme immunoassay with a biotin/streptavidin/peroxidase detection system. A polyclonal hyperimmune serum was used as a control in direct immunofluorescence tests. Both techniques based on monoclonal antibodies were more sensitive and more specific than the conventional test, the enzyme immunoassay being more sensitive than the immunofluorescence test. Small amounts of BVD viral antigen were demonstrable with monoclonal antibodies in most organ tissues.  相似文献