Showing papers by "University of Veterinary Science published in 1987"

The effect of diet, intraruminal pH and osmolarity on sodium, chloride and magnesium absorption from the temporarily isolated and washed reticulo-rumen of sheep.

Abstract: Six mature sheep fitted with rumen fistulae underwent four consecutive feeding periods, of 15 weeks each, i.e. (1) hay only; (2) 36% hay, 64% concentrate; (3) 10% hay, 90% concentrate; and (4) hay only again. The net absorption of sodium, chloride and magnesium from the washed rumen filled with artificial rumen fluids was tested during each feeding period. The artificial rumen fluids varied either in osmolarity (315 and 422 mosmol l−1) or in pH (6·78 and 4·79). Further, the surface area of rumen papillae was determined. The feeding of increasing proportions of concentrate resulted in an increase of the surface area of rumen papillae and in an elevated net absorption of sodium, chloride and magnesium. Hypertonicity (422 mosmol l−1) of the artificial rumen fluid caused net influx of water into the rumen but did not influence net absorption of the electrolytes irrespective of the feeding regimen. When the pH was lowered this led to a decrease in net absorption of sodium, chloride and magnesium and in transmural potential difference. The extent of the pH-induced decrease in net ion transport and potential difference was less in sheep receiving high-concentrate diets. When only hay was fed after the period of feeding 90% concentrate diets the surface area of the papillae, the absorptive capacity of the rumen epithelium and the resistance against low pH returned to control levels. The findings show a reversible adaptive response of rumen epithelial functions to different diets.

Postpartal ovarian function in Holstein and crossbred cows on large scale farms in Hungary.

Abstract: Summary The post partum resumption of cyclic ovarian activity was followed up by regular rectal palpation and milk progesterone assay on 249 Holstein-Friesian and crossbred cows under Hungarian large scale farm conditions. The most frequent abnormalities were delayed start of cycling (36.1%), cycles of irregular length (17.3%), cystic degeneration of the ovaries (16.5%), cessation of cyclicity (7.6%) and persistent corpus luteum (2.4%). Sometimes more than one abnormality occurred in the same animal. The duration of the post partum acyclic period correlated with the daily milk production at the peak of lactation. An increased acyclic period after calving was more frequent among heifers and cows after their fourth calving, while the occurrence of other abnormalities increased parallel to age. Ovarian dysfunction was more frequent in high yielding cows and, except for cystic ovarian degeneration, after involutional disturbances. The disturbed resumption of ovarian cyclicity had a detrimental effect on the re-conception. Zusammenfassung Postpartale Ovarfunktion bei Holstein- und Kreuzungs-Kuhen in einem Grosbetrieb in Ungarn Der Wiederbeginn der zyklischen Ovaraktivitat post partum wurde bei 249 Holstein-Friesian-und Kreuzungs-Kuhen in einem Grosbetrieb in Ungarn verfolgt. Die haufigsten Storungen waren verzogertes Einsetzen des Zyklus (36,1%), irregulare Zyklusdauer (17,3%), cystische Degeneration der Ovarien (16,5%), Sistieren des Zyklusgeschehens (7,6%) und persistierender Gelbkorper (2,4%). Manchmal traten mehr als eine Storung beim gleichen Tier auf. Die Dauer der postpartalen Azyklie war mit der Tagesmilchleistung wahrend des Laktations-Peaks korreliert. Eine verlangerte Azyklie nach dem Kalben trat bei Kalbinnen sowie bei Kuhen nach dem 4. Kalben gehauft auf, wahrend andere Storungen mit dem Alter zunahmen. Dysfunktionen des Ovars traten bei Hochleistungskuhen und, abgesehen von der cystischen Ovardegeneration, nach Involutionsstorungen gehauft auf. Storungen der Wiederaufnahme der zyklischen Ovartatigkeit hatten eine negative Auswirkung auf die anschliesende Konzeption.

Isolation and Characterization of Actinobacillus seminis Strains from Ovine Semen Samples and Epididymitis

Abstract: Summary Eighteen strains of Actinobacillus seminis isolated from ovine semen samples and epididymitis were characterized according to their cultural and biochemical behaviour. The semen samples were collected from young, unmated and mature breeding rams suffering from epididymitis or subclinical genital infection. All A. seminis strains were non-motile, non spore-forming, uncapsulated, Gram-negative pleomorphic rods, approximately 1–8 μm × 0.8-1 μm. On bovine blood agar they formed low convex, greyish-white, non-adherent and non-haemolytic colonies, which grew under aerobic conditions, but more luxuriantly when cultures were incubated in an atmosphere containing 10% CO2 at 37°C. All strains were catalase, oxidase, nitrate and ornithine decarboxylase positive, but indole, urease, phosphatase and beta-galactosidase (ONPG) negative. They were fermentative in the O/F test and usually produced acid within 1 to 3 days from glucose, arabinose, fructose, maltose and xylose, but not from lactose, mannose and sucrose. In the agar gel diffusion test, antigenic differences were demonstrated among the isolates. On the basis of the cultural, morphological and biochemical characteristics, A. seminis can be differentiated from other Gram-negative bacteria (e.g. Brucella ovis, Histophilus ovis etc.) involved in genital infections in rams.

Studies on the absorption of homologous and heterologous IgG in artificially reared newborn pigs

Abstract: The interaction of homologous and heterologous IgG during intestinal absorption was investigated using five groups of newborn piglets (50 animals in total). The diet, given via a stomach tube, was different in each group during the first 24 h. Group I received bovine colostrum, group II bovine colostrum and porcine IgG solution, group III bovine and porcine colostrum, group IV bovine colostrum and intraperitoneally applied monomeric porcine IgG, and group V received a glucose diet with no immunoglobulins. Feeding was based on bovine colostrum between the 2nd and 6th days after birth, followed by a milk replacer during the rest of the experimental period. The serum concentrations of homologous and heterologous IgG were monitored from birth to 10 weeks of age. The total serum IgG content (homologous + heterologous) of newborns was almost equal in groups I-IV at 24 h. Porcine IgG from endogenous synthesis was detectable in the serum of groups I and V two weeks postpartum. The heterologous IgG absorbed from bovine colostrum produced nearly the same serum concentration in groups II and III: hence the different components of porcine colostrum did not influence the absorption of heterologous IgG. Intraperitoneal application of 1.3 g porcine IgG in group IV resulted in a delay of the synthesis of endogenous IgG. The average half-life of heterologous IgG in the serum of groups I-IV was almost exactly the same, showing that the porcine colostrum or IgG solution did not modify the half-life of bovine IgG.(ABSTRACT TRUNCATED AT 250 WORDS)

Haemagglutination by Neisseria ovis isolated from the eyes of sheep.

Abstract: Summary The biochemical properties of and haemagglutination by 23 Neisseria ovis strains isolated from the conjunctiva of sheep, both affected with keratoconjunctivitis and normal were examined; 48 N ovis strains and 19 Moraxella bovis strains, all from cattle, were also tested Four N ovis and one M bovis strains were investigated also by electron microscopy N ovis strains from sheep and cattle revealed similar morphological and biochemical features, but ovine strains in contrast to bovine ones agglutinated red blood cells of chicken, but not those of man, cattle, sheep, horse, rabbit and guinea pig None of M bovis strains revealed any haemagglutinating activity Haemagglutinating N ovis strains grew in R type colonies The haemagglutination proved mannose resistant and was inactivated by heating the bacteria to at least 60 °C for 30 min Haemagglutination by N ovis strains isolated from several flocks of sheep was inhibited by an immune serum produced in rabbits against one of the strains Electron microscopy did not reveal any fimbriae (pili) on the surface of haemagglutinating N ovis bacteria Zusammenfassung Es wurden die biochemischen Eigenschaften von und die Haemagglutination durch 23 Neisseria ovis-Stamme, die aus der Conjunctiva von gesunden und mit Keratoconjunctivitis befallenen Schafen isoliert wurden, ferner von 48 N ovis-Stammen von Rindern und von 19 Moraxella bovis-Stammen getestet Vier N ovis-Stamme und ein M bovis-Stamm wurden auch elektronenmikroskopisch untersucht N ovis-Stamme von Schafen und Rindern zeigten gleiche morphologische und biochemische Merkmale, aber ovine Stamme agglutinierten im Gegensatz zu den bovinen Stammen rote Blutkorperchen von Huhnern, aber nicht jene von Mensch, Rind, Schaf, Pferd, Kaninchen und Meerschweinchen Keiner der M bovis-Stamme zeigte irgendeine haemagglutinatorische Aktivitat Haemagglutinierende N ovis-Stamme wuchsen in R-Form-Kolonien Die Haemagglutination erwies sich als mannoseresistent und wurde durch Erhitzung der Bakterien auf mindestens 60°C fur 30 Minuten inaktiviert Die Haemagglutination durch N ovis-Stamme, isoliert aus verschiedenen Schafherden, wurde inhibiert durch ein Immunserum, das im Kaninchen gegen einen der Stamme hergestellt worden war Die Elektronenmikroskopie zeigte keinerlei Fimbrien (Pili) auf der Oberflache der haemagglutinierenden N ovis-Bakterien