Acta Veterinaria Scandinavica

Gases containing ethylene oxide mixed with carbon dioxide alone (Etox®) or together with methyl formate (Etoxiat®) were employed for virus treatment in a way that has been shown efficient for the killing of bacteria. A number of viruses selected for their capacity to withstand chemical or physical treatments were tested under varying conditions, including in a dried state in the presence of high amounts of organic matter (animal spillings). The viruses tested were enteroviruses, paramyxovirus (NDV), poxvirus and parvovirus, and they were all inactivated to a high degree.

Corynebacterium pseudotuberculosis causes caseous lymphadenitis in sheep and goats. The animals may be infected without showing clinical symptoms. Several serotests have therefore been employed to detect infected animals. Shen et al (1982) performed an enzyme linked immunosorbent assay (ELISA) to detect antibodies against the organism using cell wall antigens. Maki et al (1985) found that the toxin of the bacterium was a better antigen for assessing infection in the ELISA test. They reported that the antitoxin ELISA appeared to be as sensitive as the antihemolysin inhibition test (Zaki 1968).

Vaccination of pigs with a killed culture of A. pleuropneumoniae serotype 5, strain K17 (subtype a) afforded a high degree of protection against challenge with strains L20 and T928 (subtype b). The reverse experiment showed that strain L20 gave good protection against challenge with strain K17 whereas strain T928 did not afford an acceptable protection against challenge with this strain. The considerable cross immunity shown to exist between strains K17 and L20 indicates a high degree of homogeneity of the antigenic determinants of the two strains involved in induction of protective immunity and suggest that antibodies to capsular subtype specific determinants may not play a significant role in the specific defence against A. pleuropneumoniae strains belonging to serotype 5. The finding that a vaccine prepared from strain T928 did not afford an acceptable protection against challenge with strain K17 indicates a variable expression among serotype 5 strains of the antigenic determinants which induce protective immunity against A. pleuropneumoniae infection.

Non-return rates at different stages after insemination were compared in daughters (n = 21,212) of five translocation heterozygous sires with all cows and heifers (n = 610,714) represented in the Norwegian Red Cattle (NRF) breeding statistics during the period October 1970 to September 1972. The daughters of the carrier bulls showed statistically significant lower non-return rates for 0–30, 30–60, 60–90, 90–120, 120–150, 150–180 and 180–270 days as compared with the control animals. The decline in non-return percentage for the daughters of translocation sires was greater than in the control animals during the period from 0–30 to 60–90 days indicating higher losses of fetuses during the early period after insemination. Daughter groups of carrier bulls consisting of adult cows only showed higher non-return rates than groups comprising both cows and heifers.

Recent epidemics of highly pathogenic avian influenza (HPAI) produced an unprecedented number of cases in mute swans (Cygnus olor) in European countries, which indicates that these birds are very sensitive to the H5N1 virus. The HPAI outbreaks stirred a debate on the controversial stamping-out policy in populations of protected bird species. After preventive vaccination had been approved in the European Union, several countries have introduced vaccination schemes to protect poultry, captive wild birds or exotic birds in zoos against HPAI. The aim of this study was to investigate the immune response of wild mute swans to immunization with an inactivated AI H5N2 vaccine approved for use in poultry. The serological responses of mute swans were assessed by comparison with racing pigeons (Columba livia), a species which is characterized by different susceptibility to infection with the H5N1 HPAI virus and plays a questionable role in the ecology of influenza (H5N1) viruses. Swans were vaccinated once or twice at an interval of 4 weeks. The humoral immune response was evaluated by hemagglutination inhibition (HI) and NP-ELISA. The lymphocyte blast transformation test was used to determine the cell-mediated immune response. Higher values of the geometric mean titer (GMT) and 100 % seroconversion (HI ≥32) were noted in double vaccinated swans (1448.2) than in single vaccinated swans (128.0) or in double vaccinated pigeons (215.3). Significant differences in HI titers were observed between swans and pigeons, but no variations in ELISA scores were noted after the booster dose. Immunization of swans had no effect on the proliferative activity of lymphocytes. The inactivated H5N2 vaccine was safe and immunogenic for mute swans and pigeons. Vaccination may have practical implications for swans kept in zoos, wildlife parks or rehabilitation centers. However, challenge studies are needed to prove the efficacy of the H5N2 AI vaccine.

Oral administration of Mycobacterium paratuberculosis to 61 pigs resulted in the development of caseous lesions of the mesenteric lymph nodes in 27.9 % of the animals. Positive results were found by bacterioscopy in 31.1 %, by culture in 60.7 % and by histological examination in 42.6 % of the animals. Histological changes typical of infection with M. paratuberculosis were found in the ileum in eight pigs. These changes, which consisted of infiltrations with epithelioid cells, were usually limited to the Peyer patches, but in one case such infiltrations were also present in the propria mucosae, similarly as in paratuberculosis in cattle.

There is a growing interest in beef cattle breeding in Sweden. The majority of the females are bred naturally, which is why it is important to choose healthy fertile bulls to obtain good reproduction and profitability. The breeding soundness evaluation includes measurement of scrotal circumference (SC). Our aim was to analyze if the SC of performance tested beef bulls has changed over the years. In total, 1332 bulls (Angus, Charolais, Hereford and Simmental) from 13 batches (1997-2010) were included in the study. Case book entries from final evaluation of the bulls, 11-13 months old, were compiled and analyzed. An overall mean SC of 34.7 cm independent of breed and age was found which is above the set minimum level. Only eleven bulls did not reach the minimum level. An increase in SC of 0.06-0.07 cm/year was shown for all breeds. In all (1997-2010), the increase of the average SC (independent of breed and age) was approximately 1 cm. The positive trend was apparent for all breeds but only statistically significant for the Charolais breed. In conclusion, our results indicated an increase in the SC over time, which improves the possibilities to obtain performance tested beef sires in Sweden with the potential for achieving better fertility results.