Gas exchange in swine before, during and after motor activity of different intensity and length

4 female and 2 male untrained fattening pigs, weighing 43.9 +/- 1.6 kg at the beginning of the experiment underwent continuous measurement of VO2, VCO2, and rectal temperature, prior to, during, and after running on a horizontal exercise belt set to speeds of 0.7, 1.3, and 2.5 m.s-1. The highest values of VO2 and VCO2 (ml-min-1/kg-1) and rectal temperature (degrees C) were usually measured few minutes after running. They were 18.84 +/- 3.65 and 20.4 +/- 4.53 as well as 41.2 +/- 0.4, 28.41 +/- 4.07 and 33.26 +/- 5.92 or 41.3 +/- 0.5, 26.21 +/- 7.7 and 32.32 +/- 7.14 as well as 40.5 +/- 0.7, depending on the above belt speeds. Exercise belt speeds of 1.3 to 1.8 m.s-1 were found to be suitable for testing aerobic metabolic capacity of untrained young pigs.     

Comparative infectivity for axenic and specific-pathogen-free chickens of O2 Escherichia coli strains with or without virulence factors

Adhesion to epithelial respiratory cells, iron acquisition, and production of K1 polysaccharide capsules have been proposed as potential virulence factors of avian Escherichia coli. These factors were studied by inoculating groups of axenic or specific-pathogen-free (SPF) chickens intratracheally with O2 E. coli strains after previous challenge with a wild strain of infectious bronchitis virus (IBV). In all experiments, the association between IBV and an E. coli strain endowed with the three virulence factors previously mentioned resulted in the most severe pathological effects, as measured by mortality, weight gains, lesions, and reisolation of E. coli from internal organs. An E. coli strain devoid of virulence factors was able only to induce mild pathological effects restricted to the respiratory tract when combined with IBV. Both E. coli strains were more invasive in axenic chickens than in SPF chickens. These results confirm the probable involvement of the three factors studied in the pathogenic properties of avian E. coli. This model can be used to assess the role of virulence factors, by comparing pairs of positive and negative isogenic strains.     

Detection of mycoplasmas in experimentally-infected bull sperm

Bull sperm pellets experimentally infected with various concentrations of Mycoplasma (M.) bovis, M. bovigenitalium, and M. californicum were stored several months at -196 degrees C and were subsequently tested for mycoplasmas, using different methods and culturing media. M. bovis was reliably identified by laboratory diagnosis up to a concentration of 10(2) cfu/pellet. M. bovigenitalium and M. californicum were found to make higher demands on the quality of culturing substrates. Recommended are 1-h broth incubation and 5-d broth breeding.     

The effectiveness of the combined treatment of thrombocytic hemorrhagic diathesis of dogs with prednisolone and blood transfusion in the model of an aspirin-produced thrombocytopathy

The administration of 20 mg/kg of acetylsalicylic acid in 18 clinically healthy dogs resulted in a thrombocytopathy with lengthened capillary bleeding time and irreversible aggregation inhibition. Through the set up of individual dilution series, one could conclude the proportional percentage of aggregation functional transfused thrombocytes. The capillary bleeding time was shortened after the intravenous injection of prednisolone (5 mg/kg) without measurable influence on the thrombocytes. Compared to the singular use of cortisone or blood transfusion alone, the effect on capillary bleeding time became magnified when one combined transfusion and corticosteroids. The fresh blood conserves (12 hours) were, with respect to the haemostyptical properties, superior to blood stored for 5 days. The component of aggregation-functional thrombocytes was, due to the prophylactic cortisone application prior to transfusion, not increased.     

Interferon in sheep]

There is only limited information on sheep interferon available. Recent publications have reported on: 1. an interferon (IFN) alpha subtype, which is secreted by the fetal trophectoderm into the lumen of the uterus between the 10th and 21st day of gestation. It was therefore named ovine trophoblast protein (oTP-1), and is responsible for signalling pregnancy to the ewe via high affinity receptors in the endometrium. It is thought that oTP-1 acts by directly influencing prostaglandin metabolism. 2. the role of lentivirus-induced interferon (LV-IFN) in the pathogenesis of Maedi/Visna. The results indicate that LV-IFN limits viral replication and therefore contributes to virus persistence and is also responsible for a chronic inflammatory process. 3. the mitogen- or antigen-dependent induction of ovine interferon gamma (IFN gamma) and its characterization.     

Determination of bacterial N portions in feces and differently collected ileum chymus from swine]

In faeces and ileal digesta samples of 31 intact (INT) as well as 73 surgically differently prepared pigs bacterial fractionations and 2.6-diaminopimelic acid (DAP) estimations were carried out in order to calculate the bacterial N proportion in faeces N and digesta N after feeding various diets. Because of a high individual variability and the analytical variation width of the DAP/N-ratios no distinct influences of the fed diets could be found. The average DAP/N-values in the faeces (0.224) of INT pigs ranged in the same magnitude as in the digesta (0.0272) of ileorectostomized (IRA) pigs with open colon descendens (IRAo), where a digesta backflow is possible. Distinct lower DAP/N-ratios (0.0125 resp. 0.0043), however, were found in the digesta of pigs with ileo-caecal cannulae (IZB) or IRA pigs with closed colon (IRAg). On the base of various premises (N of the "bacterial fraction" C is only bacterial N; the DAP found in fraction A originates from intestinal bacteria adhering to feed particles) conducted calculations of the bacterial N proportions (in per cent of total N) led to the following data: Faeces of INT pigs: 43.0 ... 68.2 vs. 69.6 ... 89.0; digesta of operated pigs (except protein free diet) IRAo: 22.3 ... 57.0 vs. 46.2 ... 73.8; IZB: 17.0 ... 35.7 vs. 25.2 ... 53.6; IRAg (only 3 pigs): 23.6 vs. 24.2. The proportion of bacterial N in the digesta N of protein free fed IRAo pigs was 22.0 vs. 22.6%.     

Nitrogen metabolism in growing swine receiving a bacterial protein supplement (Alcaligenes eutrophus) instead of soybean meal

In a balance trial with 10 pigs (mean body mass 50 kg) the influence of a bacterial protein supplement (Alcaligenes eutrophus) on N-metabolism was investigated. The bacteria were included into the diet at levels of 7 and 14% at the expense of extracted soyabean meal. Thus bacterial "pure protein" (bacterial non-nucleic acid N X X 6.25) amounted to 30 and 60% of the protein of the ration. Consuming 2 kg of feed dry matter per day the animals of the control group (I) and the experimental groups (II and III) ingested 48 g, 52 g and 55 g of total N respectively. The difference in N-intake is explained by the additional nucleic acid-N, amounting to 19,8% of total bacterial N. Daily weight gain (on average 1054 g) and feed conversion efficiency (feed ingested/weight gain; on average 1,9) were relatively improved at the highest dietary level of bacterial cell mass. Faecal N-excretion was increased significantly, whereas renal N-excretion remained unchanged. Mean apparent N-digestibility was 87,4% showing no significant difference between the experimental groups. N-balance values were noticibly increased following the intake of the bacterial protein supplement. The excretion of urinary urea-N was slightly reduced whereas 4-6 times as much allantoin-N was excreted when bacteria were fed. It is calculated that about 80% of the bacterial purines are renally excreted as allantoin and uric acid.     

Mycoplasma (M.) bovis antiserum "Dessau"--a diagnostic material for the identification of M. bovis

Mycoplasma bovis antiserum "Dessau" was used to investigate 4,553 mycoplasma strains, between 1985 and 1987, using a method described elsewhere. This diagnostic Agent is successfully used at present at all Regional Institutes of Veterinary Services throughout the GDR.