Experimental field trial with an immunostimulating complex (ISCOM) vaccine against contagious bovine pleuropneumonia

The experimental field trial with an immunostimulating complex (ISCOM) vaccine has been an occasion to explore the role of a Th1 response in the pathogenesis caused by Mycoplasma mycoides subsp. mycoides small colony (MmmSC) and in immune protection. The ISCOM complex is known to promote Th1 response. Antibodies to MmmSC were detected by indirect enzyme-linked immunosorbent assay (ELISA) in the vaccinated cattle, although the levels were lower than in a previous study. No antibodies were detected by complement fixation test (CF). After the challenge infection, vaccinated animals developed CF antibody response. They showed significantly reduced mortality compared with controls. However, gross pathological and histopathological score for vaccinated animals was as high as for the non-vaccinated, characterized by a high inflammatory reaction with histopathology dominated by interlobular pneumonia with vasculitis.     

Diurnal variation and the effect of feed restriction on plasma and milk metabolites in TMR-fed dairy cows

The objective was to study the diurnal variation in metabolites in plasma and milk of dairy cows fed total mixed rations (TMR) with a low-energy (LE) or high-energy content (HE) expected to give a minor and a major diurnal variation, respectively. Further, the purpose was to quantify and compare the responses in plasma and milk parameters when cows changed from ad libitum to restrictive feeding. Eight multiparous, early-lactating Danish Holstein cows were used in a cross-over design with two consecutive 14-day periods. Blood and milk samples were collected hourly on day 11 of each period and on days 12-14 of each period, the cows were fed restrictively (65% of ad libitum dry-matter intake). The concentration of beta-hydroxybutyrate (BHB) in plasma was significantly higher in the evening for cows fed the HE TMR, than for cows fed the LE TMR. There was a significant diurnal variation in BHB in milk, with the highest concentrations between milkings and the lowest concentrations at milking. Non-esterified fatty acids (NEFA) in plasma showed significant diurnal variation that was caused by high concentrations in the morning. Plasma glucose did not show any diurnal variation. It has been argued that feeding a TMR removes diurnal changes related to feeding, which is contrary to earlier diurnal studies where concentrates have been fed twice daily. Feed restriction increased (P < 0.001) NEFA and BHB in plasma by 121 and 90%, respectively, while the glucose concentration decreased (P < 0.001) by 19%. Milk concentrations of BHB, citrate and fat increased (P < 0.001) by 163, 11 and 26%, respectively, because of feed restriction, while there were no changes in milk protein and lactose. The relatively high increase in BHB during feed restriction suggests that BHB is more advantageous as a milk indicator of metabolic status in dairy cows than citrate and fat.     

Rumen-protected choline administration to transition cows: effects on milk production and vitamin E status

We investigated the influence of rumen-protected choline (RPC) supplementation on milk production, lipid metabolism and vitamin E status in dairy cows receiving a silage-based diet. Twenty-six Italian Holstein multiparous cows were assigned by weight and average production in the previous lactation, to one of two groups: control (no RPC supplementation) and RPC (supplemented with 20 g/day rumen-protected choline chloride). Treatment began 14 days before expected calving and continued for 30 days after parturition. Choline administration significantly increased milk production during the first month of lactation and also the concentration (and total secretion) of choline in milk, but did not affect fat or protein concentrations in milk, or plasma levels of glucose, beta-hydroxybutyrate, cholesterol and non-esterified fatty acids (NEFA). However, around parturition, NEFA concentrations in plasma were lower in treated animals than in controls, suggesting improved lipid metabolism as a result of choline supplementation. Choline supplementation also increased alpha-tocopherol plasma concentrations, suggesting a novel aspect in dairy cows.     

Effects of transcutaneous electrical nerve stimulation on the fatty acid profile of rabbit longissimus dorsi muscle (preliminary report)

This study was designed to investigate whether transcutaneous electrical nerve stimulation (TENS) of the longissimus dorsi muscle (MLD) of rabbits induces specific proportional changes in the muscle fatty acid composition. Ten 4-week-old Pannon White rabbits were exposed to TENS treatment two times a day, with the following settings: 30 Hz, 20 micros impulse length, 10 mA, 2 x 20 min. After a treatment period of 50 days rabbits were slaughtered and the fatty acid composition of the MLD was determined by gas chromatography. The TENS treatment increased the proportions of linoleic (C18:2 n-6), linolenic (C18:3 n-3) and gondoic acids (C20:1 n-9), compared with the control group. The level of palmitic (C16:0), stearic (C18:0), oleic (C18:1 n-9) and eicosapentaenoic (C20:5 n-3) acids significantly decreased. The proportion of total unsaturated fatty acids significantly increased. On the basis of the results obtained, TENS may have similar effects on the muscle fatty acid profile like physical training. Based on the supposal that the composition of membrane structure was also affected, the electrical stimulation of muscles may have further consequences, e.g. on membrane properties.     

The persistence of rabies virus antibodies in the sera of fox cubs

The persistence of maternal antibodies transfer from rabies-immune vixens to their fox cubs was studied. Eight vixens (Vulpes vulpes) were vaccinated 1 month before pregnancy with Lysvulpen vaccine for oral vaccination of foxes. Twenty-one were foxes born at the first half of April. The geometrical mean titre of rabies neutralizing antibodies of fox cubs sampled in May was 1.31 IU/ml and has dropped successively to 0.54 IU/ml in June samples and to 0.18 IU/ml in July samples. It has been proven that the duration of rabies maternal antibodies in fox cubs was limited to 2 months after birth.     

Prevalence of antibodies to Borrelia burgdorferi sensu lato in southern chamois (Rupicapra pyrenaica) in Spain

Ungulates are involved in the epidemiology of Borreliosis as maintenance hosts for vector tick species. We evaluated the prevalence of antibodies to Borrelia burgdorferi sensu lato in two different populations of southern chamois in Spain. Forty-six sera (40.4%) were positive at titres >/=1 : 64 using an indirect immunofluorescence assay (IFAT).     

Effects of low-intensity pulsed ultrasound on wound healing in corneas of dogs following keratoplasty

The effects of low-intensity pulsed ultrasound on wound healing were evaluated at the graft-cornea transition in dogs following lamellar keratoplasty using tunica vaginalis preserved in 98% glycerin. Twenty-one dogs were subdivided into three groups of seven animals. The first group (W/US) received daily treatment of low-intensity pulsed ultrasound (20 mW/cm2) for 15 min for the first 10 days post surgery. The second group (N/US) was submitted to the same procedure but with the ultrasound apparatus turned off. The third group, the control (CO), underwent the surgical procedure only. The animals were clinically evaluated during the initial (1-15 days), intermediate (16-30 days) and late (31-120 days) postoperative period. The corneas were evaluated by light microscopy at 1, 3, 7, 15, 30, 60 and 120 days after surgery. Clinically, there were no differences which would promote an advantage to any of the treatments. Light microscopy, however, revealed more extensive vascularization and more advanced wound healing in the W/US group, as well as a tendency towards early graft incorporation. Based on the present results, low-intensity pulsed ultrasound shows advantages, especially in situations where trophic support is a mandatory condition, facilitating better graft incorporation and rapid recovery of stromal organization.     

Influence of zearalenone on reproductive system cell proliferation in gilts

Zearalenone (ZEA) is a macrocyclic lactone, estrogenic, diet-depending and fusaric micotoxin, which is produced on many kinds of cereals and feeds in the favourable conditions of humidity and temperature. The structure of ZEA is similar to the structure of estrogens and it enables binding to the estrogenic receptors. The stimulation of protein synthesis in the cells of the reproductive system, which causes intensification of cell proliferation, is one of the effects of ZEA actions. Oedema and vulva reddening are the clinical, external signs of ZEA intoxication in pigs. The aim of this study was to designate the degree of reproductive cell proliferation after low doses of ZEA were applied per os in sexually immature gilts with simultaneous monitoring of zearalenone and alpha-zearalenol levels in peripheral blood. The following were observed in the gilts examined fluctuations of zearalenone and alpha-zearalenol levels in blood, which were connected with entero-hepatic circulation and also numerous histopathological changes in ovarian follicle structure. These changes were present in the reproductive system of sexually immature gilts with a big contribution of PCNA-positive cells. The studies show that zearalenone application in sexually immature gilts caused ovarian follicle atresia and apoptoso-like changes in granule cells. Intensified cell proliferation, which was expressed with the growth of PCNA index, was observed in uterus and oviduct.     

The developmental pattern of c-fos expression in the rat thalamus following open-field stress stimulation

The thalamic nuclei with their defined set of input-output connections are the primary channel for information flow to the cerebral cortex. Several data suggest that neurons of that area are involved in the response to various aversive stimulations. However the pattern of activation seems to depend on the stress model as well as the stage of maturation. In the present study we would like to check which nuclei of the thalamus show expression of c-fos in the response to the "open field test", and how this response pattern changes during the maturation process. 30 rats of age ranged from P0 to P120 (P-postnatal day) were studied. The experimental group was exposed to the "open field test" for 10 minutes. After perfusion and fixation, brains were cut and stained for c-fos with immunohistochemical method. Our results showed that during development the pattern of c-fos activity in the thalamic nuclei after stress stimulation undergoes significant changes. Distinct c-fos expression was observed in the paraventricular nucleus, intergeniculate leaflet and ventral lateral geniculate nucleus. These findings suggest that these nuclei may play a direct role in the stress reaction involved in the response to the "open field test".