4,292 research outputs found
Five years of observations of ozone profiles over Lauder, New Zealand
Altitude profiles of ozone (O3) over Lauder (45°S, 170°E) performed using a lidar, ozonesondes, and the satellite-borne Stratospheric Aerosol and Gas Experiment (SAGE II) instrument are presented. These data form one of the few long-term sets of O3 profiles at a Southern Hemisphere location. In the 5 years of data presented, the dominant variation is the annual cycle, the phase and amplitude of which differ below and above 27.5 km. Superposed are irregular episodic variations, caused by various processes. The first process studied is stratosphere-troposphere exchange, characterized by dry and O3-rich air residing in the troposphere, which was found in 21% of the measurements. The second relates to the positioning of the higher polar vortex over Lauder, often in combination with the exchange of air between midlatitude and subtropical stratospheric regions. We present examples of this which were observed over Lauder during the 1997 winter. This winter was selected for further study because of the record-low O3 amounts measured. The third process is mixing of O3-depleted vortex air with midlatitude air after the vortex breakup. We present one example, which shows that a filament originating from the depleted Antarctic vortex significantly lowers O3 amounts over Lauder around 27 November 1997. There is thus a connection between Antarctic O3 depletion and later decrease of O3 amounts at a Southern Hemisphere midlatitude location, namely Lauder
Performance of assays for testing antibodies against porcine reproductive and respiratory syndrome virus in sera collected from swine farms in a region with an extreme virus heterogeneity
Porcine reproductive and respiratory syndrome is the most economically important viral disease in the swine industry worldwide. Porcine reproductive and respiratory syndrome virus (PRRSV) strains are classified into two distinct genotypes, the European genotype and the North American genotype. The European PRRSV genotype has been divided into three subtypes: a pan-European subtype 1 and East European subtypes 2 and 3. The aim of this study was to evaluate the performance of commercial and homemade serological assays to test field sera from a geographical region with an extreme PRRSV heterogeneity. Belarus became the country of choice for sample collection because heterologous PRRSV strains of all known European subtypes circulate in this country. Sera from Belarusian swine farms were tested in immunoperoxidase monolayer assays based on pan-European subtype 1, East European subtype 3 and North American strains as antigens and commercial enzyme-linked immunosorbent assays (IDEXX and INGEZIM). The obtained results suggest that none of the serological tools for PRRSV diagnosis can guarantee a flawless detection of antibodies at the individual animal level. Considering heterogeneity of recently isolated European PRRSV strains the problem can be relevant in many countries
Influence of parenteral application of beta-carotene on fertility in cows
Thirty Holstein breed cows from the breeding stock of high yielding dairy cattle were selected for testing. The cows were selected during their high gravidity and fell into two groups. The i.m beta-carotene, Carofertin, of 20 ml (200 mg of beta-carotene) was applied to the experimental group (n=15) two weeks before the expected parturition date. Another injection of the beta-carotene preparation was applied to the experimental group two weeks after parturition. Simultaneously, a physiological solution of 20 ml was injected i.m to the experimental group (n=15). The blood samples for testing of the beta-carotene and vitamin A concentration were taken during high gravidity and in the early puerperium two days after the beta-carotene application and on the day of parturition. Two-of parenteral application of beta-carotene before parturition does not have an impact significantly on the frequency of the occurrence of retained placenta in experimental cows comparing to the cows of the control group (x=33.3 % and x=20.0 %) and length of the service period (x =97.20±31.64 and x=98.8±35.8 days). Based on the results obtained during this research, it can be concluded that the parenteral application of the beta-carotene (Carofertin) as 200 mg per cow, which is meant for protection of the reproductive disorders of cows, does not affect the level of carotinemia when its concentration in the blood serum is within the physiological limits. Therefore, no significant discrepancy in values of the reproduction figures between the cows of the experimental and control group was found. All in all, its usage is advisable only during scarce feeding
The effect of different acute concentrations of cadmium chloride on the frequency of micronuclei in AO rats
Cadmium (Cd) is highly toxic heavy metal which may cause severe biological
effects in vivo and in vitro. In this study, an evaluation of the acute Cd
ability to trigger micronuclei (MNi) formation was carried out on 3-monthold
male and female Albino Oxford (AO) rats using micronucleus (MN) test.
Experimental animals were treated intraperitoneally with three different
concentrations of cadmium chloride (CdCl2): 0.5, 1, and 2 mg CdCl2 per kg of
body weight. Control animals received equal volume of sterile phosphate
buffered saline. The results showed that 2 mg CdCl2 per kg b.w. concentration
caused a highly statistically significant (P < 0.001) increase in MNi
formation in the bone marrow polychromatic erythrocytes (PCEs), exerting a
clear-cut concentration-dependent effect. Lower concentrations of CdCl2 used
(0.5 and 1 mg/kg b.w.) also caused MNi formation, but with lower statistical
significance. Sex differences in MNi production in bone marrow PCEs after
acute exposure to different experimental concentrations of CdCl2 were not
observed in our study. Our results indicate the ability of CdCl2 to exerts
genotoxic effects in bone marrow of AO rats, and complement previous data on
the genotoxicity of this important environmental contaminant, burdening the
body from different sources - major being industrial exposure, food and
cigarette smoking. [Projekat Ministarstva nauke Republike Srbije, br. III46002
Efficiency evaluation of a bivalent vaccine in the prophylaxis of mastitis in cows
Mastitis in cows represents one of the most actual problems in intensive
dairy production. The longtime different approaches to the treatment of
mastitis have not offered a suitable solution, and the problem of mastitis is
still present and acute. Prevention of pathogen penetration into the mammary
gland, its colonization and multiplication impose a constant need for regular
inspections of milk, as well as preventive and therapeutic measures to reduce
the incidence of mastitis. Studies in the field of vaccination of ruminants
against mastitis pathogens suggest a limited success in obtaining significant
results in immunoprophylaxis. Considering the results of other researchers
and our own research, and bearing in mind the problems mastitis caused by
Staphylococcus aureus and Streptococcus agalactiae represent, the aim of this
study was the preparation and testing of an indigenous vaccine prepared with
two stable strains, SAU 7 (S. aureus) and SAG 3 (Str.agalactiae). The dose
was 5 mL/cow and consisted of inactivated bacterial S. aureus SAU 7 cells in
a concentration of 1x1010 cfu/mL and Str. agalactiae SAG 3 in a concentration
of 4 x 109 cfu/mL. The number of somatic cells in the milk samples during the
whole study period was higher in vaccinated cows in both groups compared with
the control, but this difference was not statistically significant. The
concentration of immunoglobulin IgG in the milk of vaccinated cows was
significantly higher than the concentration of this class of proteins in the
milk of unvaccinated cows. [Projekat Ministarstva nauke Republike Srbije, br.
III 46002
The nutritive value of Valjevac grassland - Zasavica reservation
Valjevac pasture of Zasavica reservation with its area of 300 ha presents a
significant area for grazing cattle. In order to evaluate its potential for
livestock production, the botanical and chemical composition of hay in three
different time periods was observed (spring, summer and autumn). The
determined plants species confirmed the richness of Zasavica grasslands, as
well as the presence of dry, moist and forest habitat plants. The analyzed
plants mostly belong to the Poaceae, Fabaceae, Asteraceae and Plantaginaceae
families. Chemical analysis determined that the protein content decreased
(P<0.01) from April (17.22±0.40 %) to October (10.30±0.16 %), and cellulose
content increased (P<0.01) (from 19.07±0.38 % in April to 21.65±0.41 % in
October). The calculated energy density of hay samples ranged from 0.425
Starch Units (SU) in October, 0.443 SU in April to 0.448 SU in June. The
Valjevac pasture with its numerous plant species is of great importance in
upkeeping biodiversity and also presents a solid base for livestock
production. The determined levels of manganese and copper point out to the
need of copper supplementation especially during the late summer and autumn
periods. [Projekat Ministarstva nauke Republike Srbije, br. III46002
Recognition and assessment of pain in animals
Pain is a complex physiological phenomenon, it is hard to define in a satisfactory manner in human beings, and it is extremely difficult to recognize and interpret in animals. According to the International Association for the Study of Pain (IASP), pain is defined as an unpleasant sensory or emotional experience associated with actual or potential tissue damage. Pain is an important aspect of life and its prevention and decrease are important as a goal to achieve the well-being of animals. The task of scientists is to recognize the language of pain interpretation which animals use to seek help. For an objective evaluation of pain, it is essential to possess a good knowledge of physiology, etiology and clinical diagnosis. We are obliged to do this also because of the ethic principles to defend the well-being of animals and to eliminate any factor which can cause feelings of pain or suffering. The recognition of pain and its manifestation is especially important in cases of animal abuse, when it could be the only symptom. Animals can be quiet and instinctively hide the presence of pain, which makes the symptoms more subtle, but does not make their injuries any less painful. It is also important to have knowledge of manifestations of pain that appear during different surgical procedures performed by the veterinarinarian in spite of the applied dose of analgetic. Pain significantly contributes to the suffering of animals and in such cases it is important to collect relevant documents, in the form of video recordings or in photodocumentation form, because it is important information in the processing of cases of animal abuse. Veterinary experts have the responsibility to recognize, evaluate, and prevent pain and to relieve animals from the pain, which should be the fourth vital sign, following temperature, pulse and breathing, and participate in the evaluation of the condition of the animal during an examination. Due to all the above mentioned, it is essential to secure efficacious prevention and control of pain, which is reflected in the recognition of pain, making a diagnosis, developing a plan of therapy, and adapting the therapy over a longer time period, especially in cases of chronic pain
Investigations of prevalence of antibodies to B.canis in stray dogs in territory of Belgrade
The paper covers investigations of stray dogs in the territory of the city of Belgrade. A total of 184 blood serum samples were examined for the presence of antibodies specific to Brucella canis. The method of slow agglutination in a test tube with 2- mercaptoethanol was used in the diagnostic procedure. Of the 184 examined serums, 49 (26.63%) had a titer of 1/50, 25 serums had a titer of 1/100 (13.58%), while 20 serums had a titer equal to or bigger than 1/200 (10.87%). Furthermore, 15 samples of full blood from serologiclly negative animals were also presented for isolation. The bacteriological finding for these samples was negative. The obtained results indicate that the number of seropositive stray dogs in the territory of Belgrade is extremely high and that 10.87% of the testes animals are definitely infected with Brucella canis
Esubacute acidosis in rumen of high-yield dairy cows: Prevalence and prevention
The objective of the investigations presented in this paper was to establish the frequency of the incidence of subacute acidosis in the rumen of cows (SARA) in the first three months of lactation and the possibilities for its prevention using a mineral mix based on bentonite, zeolite, magnesium oxide, and sodium bicarbonate (Mix plus). The values obtained for the rumen pH content show that subacute rumen acidosis occurs in in 20 percent of the examined cows in the early stage of lactation. For these investigations, cows in early stages of lactation were chosen and divided into 2 groups. Cows of the experimental group were administered a fodder mix which contained the mineral mix for a buffer effect (Mix plus). The average values of the rumen pH content in the control and the experimental group of cows at the beginning and on the 30th day of the experiment were approximately the same and did not differ significantly (p>0.05). On the 60th day of the experiment, the values for the electrochemical reaction of the rumen content for the control group amounted to an average of 6.219±0.18, and for the experimental group of cows it was 6.772±0.23. The obtained difference was statistically very significant (p<0.001). At the end of the experiment, on the 90th day, the average pH value of the rumen content of cows of the control group was 6.308±0.16, while this value in the experimental group of cows was significantly higher and amounted to 6.676±0.29 (p<0.01)
- …