| 28601. |
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| 28602. |
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| 28603. |
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| 28604. |
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| 28605. |
- Pettersson, Ann
(författare)
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Tooth Resorption in the Swedish Eurasion Lynx (Lynx lynx)
- 2010
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Ingår i: Journal of Veterinary Dentistry. - : SAGE Publications. - 0898-7564 .- 2470-4083. ; 27, s. 222-226
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Tidskriftsartikel (refereegranskat)abstract
- The etiology of tooth resorption in the domestic cat remains unknown. The high prevalence and progressive nature of the disease complicates defining healthy control groups. In order to evaluate the possible influence of various life style changes on the prevalence of tooth resorption, healthy control groups are a prerequisite. This paper presents a prevalence study for tooth resorption in a free-ranging wild felidae population. Skulls from 46 free-ranging Eurasian lynx (Lynx lynx) were examined. The age of the animals had previously been estimated based on cementum annuli in the maxillary right canine tooth. The dental examination included both dental probing and radiographic imaging. Complicated fractures of the canine teeth were found in 9/46 (19.5 %) skulls. In one fractured canine, apical root resorption and periapical lucency was detected. The root resorption was attributed to inflammatory resorption as a consequence of the initial dental trauma and necrotic pulp. No signs of tooth resorption were found in the remaining teeth. Supernumerary roots were detected in 18/46 skulls (39.1 %). Supernumerary "peg" teeth caudal to the mandibular first molar tooth were detected in 6/46 (13.0 %) skulls. Although further studies on dental ultra-structure are needed, the Swedish Eurasian lynx may, in the future, be useful as a healthy comparative model for studies on the etiopathogenesis of tooth resorption in the domestic cat. J Vet Dent 27(4), 222 - 226, 2010
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| 28606. |
- Pettersson, Catharina, et al.
(författare)
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Dating of groundwaters by ¹⁴C-analysis of dissolved humic substances
- 1991
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Ingår i: Humic substances in the aquatic and terrestrial environment : proceedings of an international symposium, Linköping, Sweden, August 21-23, 1989. - Berlin Heidleberg New York : Springer. - 3540537023 ; , s. 135-141
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Bokkapitel (refereegranskat)abstract
- Fulvic acids of the DOC of five deep (139-409 m) groundwaters were recovered (adsorption on DEAE-cellulose) and used for age determination (14C determined by accelerator mass spectrometry), and compared with fulvic acids recovered from a shallow groundwater and a surface water. The composition of the seven different fulvic acids was similar, despite variations in hydrochemical conditions and residence times, indicating a high stability of this molecular weight fraction. The ages calculated from the 14C-content of the fulvic acid fraction (600 to 10000 y) are less than the ages indicated from analyses of the dissolved carbonate (data available for three sites). Using a fraction of the DOC with high stability (like the fulvic acid fraction) as a 14C-source when assessing the ages of subsurface waters, appears to be superior to using dissolved carbonate.
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| 28607. |
- Pettersson, Emelie, et al.
(författare)
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Detection and molecular characterisation of Cryptosporidium spp. in Swedish pigs
- 2020
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Ingår i: Acta Veterinaria Scandinavica. - : Springer Science and Business Media LLC. - 0044-605X .- 1751-0147. ; 62
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Tidskriftsartikel (refereegranskat)abstract
- Background Cryptosporidiumis a genus of apicomplexan parasites that cause enteric disease in vertebrates. In pigs, infections are most often asymptomatic, but may result in diarrhoea and poor growth. The most common species detected in pigs areC. suisandC. scrofarumwith low zoonotic potential.C. parvum, with higher zoonotic potential, may also be found. As previous knowledge on the occurrence ofCryptosporidiumin Swedish pigs is scarce, this was investigated in our study. Faecal samples from 13 pig herds were collected and a total of 222 pooled pen samples, from suckling piglets (n = 48), growers, aged 6-12 weeks (n = 57), fatteners, aged 13-24 weeks (n = 67) and adult animals (n = 50) were included. Samples were analysed using microscopy and positive samples were further analysed using polymerase chain reaction and sequencing of the 18S rRNA gene and the 28S rRNA gene to determine species. Results Cryptosporidiumspp. were detected in all sampled herds and in 25% (56/222) of the individual pen samples. Infections were most common in growers and fatteners with 51% (29/57) and 35% (20/67) positive samples in each group, respectively. The piglets had 8% (4/48) positive samples and adults had 6% (3/50). Species determination showedC. suisandC. scrofarumin piglets and growers,C. scrofarumin the fatteners, andC. suisandC. parvumin the adults. Although no mixed infections could be confirmed we saw signs of double peaks in the 28S rRNA gene chromatograms, possibly indicating more than one species present per sample. Conclusion Cryptosporidiumspp. were detected on every sampled farm and in 25% of the individual pen samples in our study. We therefore conclude thatCryptosporidiumspp. are present and likely common in Swedish pig herds, where pigs are loose and reared on solid floors. However, none of the farms reported any problems with poor weight gain, diarrhoea, or reduced appetite in their pig herds. The pig adaptedC. suisandC. scrofarumwere the predominant species identified. Two samples were positive for the more zoonoticC. parvum, and pigs should hence not be disregarded as a possible source of zoonotic cryptosporidiosis.
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| 28608. |
- Pettersson, Emelie
(författare)
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Gastrointestinal parasites in pigs : prevalence, risk factors and control
- 2021
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Doktorsavhandling (refereegranskat)abstract
- Gastrointestinal parasites are common in pigs worldwide, and in all production types. Clinical disease is rare and mainly associated with heavy nematode infections, or piglets infected with the coccidia Cystoisospora suis. Subclinical infections are more common and may result in reduced growth and poor feed utilisation. This can in turn affect pig health as well as the sustainability and productivity of the farm. The aim of this thesis was to update the knowledge of gastrointestinal parasites in Swedish pig herds, as this was last done in the 1980s. Since then, major changes in the national pig production have occurred with e.g., higher demands on animal welfare and improved biosecurity. Management routines related to parasite control were investigated using a questionnaire. Strategic hygiene and biosecurity practices were commonly practiced for growing pigs but less so for adult animals. Moreover, antiparasitic drugs were frequently used by routine. The occurrence of gastrointestinal parasites was assessed in three different studies. Oesophagostomum spp. were the most common parasites and found mainly in sows. The prevalence of Ascaris suum in growing pigs was reduced compared to previous studies. C. suis was common in piglets on a herd basis and Cryptosporidium spp. were found on all sampled farms. Finally, the efficacy of the available anthelmintic drugs was investigated, and for the first time in Sweden a reduced efficacy of ivermectin on Oesophagostomum spp. was identified. In conclusion, several changes in both the prevalence and control of gastrointestinal parasites were identified in this thesis. This new knowledge can in turn contribute to healthier pigs and a more sustainable and profitable pig production.
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| 28609. |
- Pettersson, Emelie, et al.
(författare)
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Gastrointestinal parasites in Swedish pigs: Prevalence and associated risk factors for infection in herds where animal welfare standards are improved
- 2021
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Ingår i: Veterinary Parasitology. - : Elsevier BV. - 0304-4017 .- 1873-2550. ; 295
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Tidskriftsartikel (refereegranskat)abstract
- The global pig production has undergone major changes over the past 30 years with larger farms, more intensified production as well as improved hygiene and biosecurity practices. To investigate whether these changes, along with expanded pig welfare, have had an impact on parasite occurrence, a cross-sectional study was conducted in Sweden on farms where the pigs are always loose-housed, floors are solid and bedding material is provided. A total of 1615 faecal samples were collected on 42 conventional indoor farms from a) post-weaning piglets (n = 337); b) growers (n = 345); c) fatteners (n = 308); d) dry sows (n = 277) and e) pre-partum sows (n = 348). Samples were analysed using centrifugal flotation with a saturated glucose-salt solution and a modified McMaster technique, with a lower detection limit of 50 eggs or oocysts per gram. Samples positive for strongyle-type eggs were cultured to third stage larvae for genus identification. Farms also responded to a questionnaire regarding biosecurity, hygienic measures, and other management routines. Risk factors for parasite occurrence were assessed using mixed-effects logistical regression to account for farm-level clustering of samples. Interestingly, the prevalence of Ascaris suum was reduced compared to a similar investigation in the 1980s. In the present study A. suum was detected only in 43 % of the herds, with the highest prevalence in pre-partum sows (37 %) followed by fatteners (25 %). Small sized farms were associated with higher odds of being positive, compared to large sized farms (OR = 159.1, P = 0.010). Oesophagostomum spp. were detected in 64 % of the herds and again mainly in pre-partum sows (63 %). Trichuris suis was detected in 10 % of the herds but only in <1% of the samples. Moreover, Cystoisospora suis and Eimeria spp. were detected on 60 % and 64 % the farms, with the highest prevalence in post-weaning piglets and sows, respectively. Anthelmintic drugs (ivermectin or fenbendazole) were commonly used and administered mainly to pre-partum sows on 93 % of the farms. Toltrazuril against neonatal coccidiosis was administered to piglets on 14 % of the farms. The use of antiparasitic drugs did not significantly affect parasite prevalence. Overall, it appears that the altered farming routines with focus on improved pig welfare have not solely resulted in a higher occurrence of parasites, most likely due to the adequate biosecurity and hygiene practices instituted. Thus, there seems to be no conflict between implementing measures to promote pig welfare and adequately control the more pathogenic and economically important parasites.
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| 28610. |
- Pettersson, Erik
(författare)
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Höstrapsetablering med myllningsteknik och direktsådd
- 2009
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Arbetet är en studie av höstrapsetablering med direktsådd och myllning av kultivator med frösålåda och är gjort i samarbete med Väderstad-Verken AB. I detta examensarbete har jag följt en försöksserie (R2-4143) där jag jämfört olika etableringsmetoder för höstraps. De metoder som studerats är plöjning med konventionell sådd, grund bearbetning och sådd, sådd med TopDown med frösålåda samt direktsådd med och utan förredskap. Försöksplatserna har legat i Skåne, Uppland och Östergötland. Jag har utfört fältmätningar från sådd till invintring. Jag har också intervjuat odlare som har sått med kultivator med påmonterad frösålåda för att se vad de tycker om metoden och hur mycket den skiljer från deras tidigare etableringsmetod. Sommaren 2008 var mycket torr och avlöstes av regn på hösten vilket gjorde att rapsfröet grodde lätt på de flesta platser i Sverige. På vissa platser kom det så stora mängder att rapssådden inte kunde genomföras. Etableringen i försöksserien R2-4143 blev överlag jämn och det som påverkade uppkomsten var halminblandningen i kombination med fröets kontakt med finjord. Plantuppkomsten på försöksplatserna har överlag varit god. Plöjda led och led som kultiverats med TopDown biodrill (frösålåda) har i medeltal givit en något bättre etablering sett över alla platserna. Enligt mätningarna under hösten ser det ut som att alla metoderna i försöksserie R2- 4143 kan fungera för att få ett bra bestånd. Det är svårt att utifrån ett års resultat avgöra vilken metod som ger bäst uppkomst. Det är årsmånen, typ av jord på fältet, markens fuktighet och förfrukten som bestämmer hur etableringen blir. De lantbrukare som myllat sin höstraps med kultivator, Carrier eller Seed Hawk var överlag nöjda med sin etablering. Kultivator med frösålåda är ett system som verkar fungera bra. Det som krävs är dock mer växtskydd i jämförelse med ett konventionellt system för att bli kvitt spillsäd och ogräs. TopDown fungerar bra på de flesta jordar och har bra flexibilitet vad gäller väderlek då det går att köra. TopDown med biodrill verkar vara ett system som fungerar bra och där lantbrukarna är nöjda med resultatet av sådden
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