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Sirvi Autor "Kask, Kalle (advisor)" järgi

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  • Pisipilt
    Kirje
    Clinical mastitis in Estonia: diagnosis, treatment efficacy and antimicrobial resistance of pathogens in Estonia
    (Eesti Maaülikool, 2014) Kalmus, Piret; Orro, Toomas (advisor); Kask, Kalle (advisor)
    Mastitis is a most common bovine disease, causing a large economic impact on dairy industry, due to increased treatment cost, decreased milk quality and unnecessary culling of dairy cows. The primary objective of present research was to evaluate clinical mastitis pathogens, antimicrobial resistance and treatment efficacy in Estonian dairy cows. The second objective was to find association between local inflammatory reaction in the udder and bacteriological diagnosis of clinical mastitis using PCR-based method. The clinical mastitis udder pathogens and risk factors in primiparous and multiparous dairy cows were evaluated in eleven Estonian dairy herds. During one-year study period, the incidence rate of clinical mastitis at calving was 6.4% among 1053 primiparous dairy cows. The study showed that housing system was not a significant risk factor for clinical mastitis of freshly calved heifers. Moving heifers to the calving facilities too late increased risk for clinical mastitis at parturition in tie-stall farms. The isolated udder pathogens in heifers did not differ significantly in tie-stall farms compared to freestall farms, but differences were found between heifers and multiparous cows at parturition. To estimate the distribution of udder pathogens and their antibiotic resistance in Estonia during the years 2007-2009, 3058 clinical mastitis samples from 190 farms and 5146 subclinical mastitis samples from 274 farms were investigated. Streptococcus uberis was the bacterium isolated most frequently (18.4%) from cases of clinical mastitis, followed by E. coli (15.9%) and Streptococcus agalactiae (11.9%). The bacteria that caused subclinical mastitis were mainly Staphyloccus aureus (20%) and coagulase-negative staphylococci (15.4%). Antimicrobial resistance was highly prevalent. The proportion of Staphylococcus aureus and CNS isolates that were resistant to penicillin was 61.4% and 38.5%, respectively. Among the E. coli isolates, ampicillin, streptomycin and tetracycline resistance were observed in 24.3%, 15.6% and 13.5%, respectively. The quantity of bacterial DNA in milk samples was associated with concentrations of APP and NAGase activity in the milk. These indicators reflect the inflammatory reaction in the mammary gland, and their concentrations increased with increasing severity of mastitis. Concentrations of APP and NAGase activity in milk significantly differed between different mastitis-causing bacterial species. Milk amyloid A and Hp concentrations and NAGase activity were significantly higher in samples with large quantities of bacterial DNA from Escherichia coli or Streptococcus dysgalactiae compared with milk samples not containing those species. Milk samples containing Corynebacterium bovis and coagulase-negative staphylococci had significantly lower concentrations of MAA and Hp and lower NAGase activity compared with samples where these species were not detected. The efficacy of benzylpenicillin for the treatment of clinical mastitis (n=140) caused by Gram-positive bacteria susceptible to penicillin in vitro was not affected by the route of drug administration. Altogether, 80.3% of the quarters with systemic treatment and 74.7% of the quarters with IMM treatment exhibited a clinical cure, and 54.1% and 55.7% exhibited a bacteriological cure, respectively.
  • Pisipilt
    Kirje
    Factors that mare owners use to select the stallion for their mare
    (Eesti Maaülikool, 2024) Hämäläinen, Jenni; Kask, Kalle (advisor); Orro, Toomas (advisor)
    Horses have been selectively bred over the centuries for different purposes which has caused changes in the morphology, physiology, behaviour and performance of many breeds. The breeding of work horses for agricultural and forestry purposes has decreased and breeding is more focused on producing horses for different sporting activities and hobbies. Selection of horses for breeding has been mainly made based on the pedigree, performance results and temperament of the horse. Although, depending on the use, different breeds have been bred forward looking out for specific traits like speed, size or colour. This has entailed the decreasing of genetic variation and increasing of genetic mutations. Breeders' choices have been modified by the breeds and have had far reaching consequences. In the case of the sport horse breeding money – driven business will guide the breeding choices, whereas small scale breeder could have more options to choose a stallion that respond to his/her personal preferences. In Finland, the horse breeding tradition is quite young, but in recent years breeding has been focused on a wider area, different disciplines and more specific targets. Besides the professional breeders usually focused on sport horses, in Finland there are many smaller breeders who do not have such a clear breeding plan, or they are making the foals for their own purposes only. The online questionnaire made for Finnish mare owners examined the most important factors they use in stallion selection but also the planned breeding site, technique and possible breeding applications they use in the decision making. All the breeding orientations valued the conformation and size, pedigree and the temper of the stallion to be the most important traits. Competition results, studbook scores and progeny also play an important role whereas genetic diversity and inbreeding had quite a small effect on breeding choices. Insemination on the stud farm with chilled semen was found to be the most popular option. In breeding decision making breeders used the information found in databases of the breeding associations and studbooks.
  • Pisipilt
    Kirje
    Prostaglandin F2α and Parenteral Antibiotics as a Treatment of Postpartum Metritis and Endometritis, and Possible Relation of Acute Phase Proteins With Subsequent Fertility in Dairy Cows
    (Eesti Maaülikool, 2015) Jeremejeva, Julia; Kask, Kalle (advisor); Orro, Toomas (advisor)
    This study was designed to get additional knowledge about the treatment of postpartum (PP) clinical metritis (CM) and clinical endometritis (CE), using a combination of systemic antibiotics with administration of prostaglandin F2α (PGF2α), to determine the optimal time of treatment, and to study the effects of this treatment on clinical, physiological and fertility parameters. The second aim of the study was to determine of the diagnostic role of acute phase proteins (APP), and the exposure of treatment success using prescription of APP in the case of CM and CE. Furthermore, to evaluate the potential association of APP as inflammatory mediator, with subsequent fertility in dairy cows suffering from CM or CE, treated with different methods, in comparison with untreated diseased and healthy control cows. Three clinical studies, and one additional study, were carried out. Late pregnant dairy cows (21 animals in the first study, 68 in the second and 67 in the third study) with diagnosed CM and CE were divided into experimental and positive control groups, and negative control groups were composed of healthy cows. Measurements of body temperature, examination of general health status and vaginal discharge, ultrasonographic or bacteriological and cytological examinations, determination of plasma or milk progesterone, measuring of APP and data of fertility parameters were used for evaluation of treatment success. Using a combination of systemic administrations of ceftiofur with two injections of PGF2α at intervals of 8 h, was compared with using an oxytocine analogue and intrauterine administration of cephapirin and a combination of intramuscular administration of ceftiofur with flunixin. Treatment of CE was tested using systemic administrations of ceftiofur with two injections of PGF2α at intervals of 8 h in the early PP (5-10 day after calving) and late PP (30-35 day PP). The findings of this study indicate that treatment of CM using ceftiofur in combination with PGF2α, in comparison with a combination of oxytocin with intrauterine administration of cephapirin, showed no clear difference nor effect on the improvement of clinical signs nor inflammatory parameters during the early PP, neither on bacteriological and cytological findings during the late puerperal period. Treatment of CM and CE using flunixin, in addition to parenteral antibiotic, did not improve clinical recovery, or inflammatory parameters or elimination of bacteria from the uterus. Regardless of the more severe inflammation that was detected in animals from the group treated by parenteral administration of antibiotic with PGF2α (higher body temperatures and concentrations of haptoglobin) they showed the same fertility parameters as healthy animals. The results of this study suggest that treatment of CE in the early PP period, using systemic administration of ceftiofur with two injections of PGF2α at intervals of 8 h, could be more preferable to using the same treatment in the late PP. However, this difference was not significant and studies with larger sample sizes should be undertaken to confirm this hypothesis. The findings of an additional study indicate that plasma APP, measured during the PP period, are negatively associated with subsequent fertility in treated CM and CE animals, as well as in untreated and healthy dairy cows.