The effects of aviation noise on reproduction in farmed blue foxes:a pilot study

Jaakko Mononen, Hertta Pulkkinen, Teija Pyykönen, Jyrki Juntunen, Sari Hänninen and Leena Ahola


The Finnish Air Force (FAF) cannot fully avoid flying over fur farms during the breeding season. FAF pays yearly for cub losses assumed to be caused by aviation noise. Our aim was to study how aviation noise affects reproduction and behaviour of farmed blue foxes (Alopex lagopus), the most important fur animal in Finland. Forty-nine artificially inseminated/mated blue fox vixens were exposed to aviation noise from F-18 Hornet jet fighters flying near and over the experimental farm. The flights were repeated during five days during the time the vixens were pregnant or had cubs. The noise on the level of the fox cages was LAFmax 84-107 dB. The behaviour of 40 females was observed at the experimental farm during one noise exposure. Forty-nine vixens at another farm without any flight activity acted as control animals. Reproductive performance data were recorded and collected from both farms. The average reproductive performance (on 1st of July) was better on the aviation noise farm (4,7 ± 4,3 cubs/breeding female) than on the control farm (3,9 ± 4,3), but this difference was not statistically significant. However, aviation noise may have a negative effect on the reproduction of primiparous vixens. The vixens could be classified to three categories according to their behaviour during the aviation noise: fearful (30 % of animals), alert (43 %) and passive (28 %). The behaviour of the vixens was not related to their reproductive performance. Our study was a pilot study, and the number of animals was limited to allow any firm conclusions. However, the results may show that exposure to rather strong and repeated aviation noise does not necessarily impair blue foxes’ reproductive performance. On the other hand, some of the vixens clearly regarded the noise as aversive.

High prevalence of pathogenic Yersinia enterocolitica on pig heart, liver, kidneys and ears

Tiina Korte, Maria Fredriksson-Ahomaa ja Hannu Korkeala


The pig is known to be an important reservoir for pathogenic Yersinia enterocolitica. Many pigs carry this microbe in tonsils. Tonsils are re-moved together with the pluck set, including liver, heart and kidneys. During the evisceration, the spread of pathogenic yersinia from the tonsils to pluck set is unavoidable. The aim of this work was to study the prevalence of pathogenic Y. enterocolitica on pig offals, including liver, heart and kidneys, and ears, and to characterise the isolates with the pulsed-field gel electrophoresis (PFGE) method. The prevalence was high, especially when detected with the PCR-method. All pathogenic iso-lates were belonging to bioserotype 4:O3. The most common genotype was G3, which was found from different sources during the hold sam-pling time. The same genotype is the most common type found from pig tonsils indicating that the tonsils are an important source of contamina-tion of offals with the pathogenic Y. enterocolitica. The high contamina-tion of offals is a health risk to consumers. To decrease the health risk of the contaminated offals by changing the slaughtering methods, the law has to be changed.