| 1. |
- Höglund, Johan, et al.
(författare)
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Infection dynamics of Ascaridia galli in non-caged laying hens
- 2011
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Ingår i: Veterinary Parasitology. - : Elsevier BV. - 0304-4017 .- 1873-2550. ; 180, s. 267-273
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Tidskriftsartikel (refereegranskat)abstract
- The infection dynamics of Ascaridia gall in laying hens was investigated in six commercial non-caged flocks. Three flocks were managed in accordance with the regulations for organic production and had outdoor access, whereas three flocks were housed indoors in aviaries or traditional floor systems. Faecal egg counts and total worm burdens were determined at specified intervals during the first 50 weeks of the production period. In two conventional flocks the efficacy of flubendazole on lumenal stages was investigated. All flocks became infected following the arrival of the birds (post placement) with residual infective eggs derived from the previous flock. In four flocks (two organic and two conventional) parasite eggs were first detected in faeces 6-7 weeks post placement, whereas parasite eggs were not detected until after 17-18 weeks in two flocks. This delay was observed in two of three flocks that were housed in barns that had been thoroughly cleaned and disinfected by chlorocresol. In three flocks (two conventional and one organic) flubendazole was administered to the birds in the drinking water for approximately one week. Both conventional flocks were dewormed twice approximately 20 weeks apart, whereas the organic flock was dewormed only once about 40 weeks post placement. Parasite eggs reappeared after deworming in all flocks, often within 2-4 weeks, followed by a rapid increase in parasite egg expulsion. Our results suggested impairment of host immunity post treatment, as the egg counts exceeded pre-treatment levels after 7-8 weeks on both conventional farms. Accordingly, the way by which anthelmintics and/or disinfectants are used in non-caged chicken flocks must be refined. (C) 2011 Elsevier B.V. All rights reserved.
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| 2. |
- Jansson, Desirée, et al.
(författare)
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Anticoccidial Vaccination Is Associated with Improved Intestinal Health in Organic Chickens
- 2022
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Ingår i: Veterinary Sciences. - : MDPI AG. - 2306-7381. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- Simple Summary In recent years, the number of organic chicken farms has increased. Chickens can be infected by single-cell parasites, coccidia, which cause lesions in the lining of the intestine leading to poor growth and sometimes death (coccidiosis). This infection can also lead to overgrowth in the intestine of a bacterium, Clostridium perfringens, that may cause further damage (necrotic enteritis). Prevention is often achieved by adding substances in the feed that will slow down the development of parasites and bacteria, but this is not allowed in organic farming. The aim of this study was to investigate if vaccination against coccidia can prevent these diseases in organic chickens. Vaccinated chickens developed milder gut lesions, had fewer and less damaging C. perfringens, and had similar or higher body weight compared to unvaccinated chickens six weeks after vaccination. No deaths from coccidiosis or necrotic enteritis occurred among vaccinated chickens while some unvaccinated chickens died from these diseases. We conclude that vaccination against coccidia benefits organic chickens. This study provides knowledge supporting further development of the organic chicken industry. The results are also of relevance to the management of coccidiosis and necrotic enteritis in conventional broilers. Eimeria spp. and Clostridium perfringens (CP) are pathogens associated with coccidiosis and necrotic enteritis (NE) in broiler chickens. In this study we evaluated the effect of anticoccidial vaccination on intestinal health in clinically healthy organic Ross 308 chickens. On each of two farms, one unvaccinated flock (A1 and B1) was compared to one vaccinated flock (A2 and B2) until ten weeks of age (WOA). Faecal oocysts were counted weekly, and species were identified by PCR (ITS-1 gene). Lesion scoring, CP quantification and PCR targeting the CP NetB toxin gene were performed at three, four, and six WOA and chickens were weighed. Necropsies were performed on randomly selected chickens to identify coccidiosis/NE. Oocyst shedding peaked at three WOA in all flocks. Later oocyst shedding (E. tenella/E. maxima) in unvaccinated flocks at 5-7 WOA coincided with coccidiosis/NE. Although results differed somewhat between farms, vaccination was associated with lower intestinal lesion scores, reduced caecal CP counts, lower proportions of netB-positive CP, lower body weight at three-four WOA, and similar or slightly increased body weight at six WOA. In conclusion, the intestinal health of organic broilers can benefit from anticoccidial vaccination when oocyst exposure levels are high.
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| 3. |
- Jansson, Desirée, et al.
(författare)
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Ascarid infections in laying hens kept in different housing systems
- 2010
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Ingår i: Avian Pathology. - : Informa UK Limited. - 0307-9457 .- 1465-3338. ; 39, s. 525-532
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Tidskriftsartikel (refereegranskat)abstract
- The present study was undertaken to investigate the prevalence of ascarid infections in Swedish commercial laying hens in 2004 and 2008 following a recent nationwide change to alternative housing systems but before anthelmintics became available. Also, the influence on prevalence of farm and flock characteristics and management was studied in 2004. The results showed that the overall prevalence was significantly higher in 2008 (38%; n = 64/169) compared with 2004 (24%; n = 44/186) (P = 0.001). Ascarid infections were rare in caged flocks, including furnished (enriched) cages, both years (2.4 to 4.3%), and were significantly more common in non-cage systems in both years (16.7 to 48.6% in 2004, and 28.6 to 77.1% in 2008 depending on the housing system). There was no significant difference in prevalence between hens kept on litter indoors and free-range/organic hens. The absence of a hygiene barrier at the entrance of the house or unit increased the risk of infection (P 0.001), which suggests that parasite eggs were introduced horizontally to the farms. The risk of infection also increased with the age of equipment used in the barn; for example, the risk increased with an odds ratio of 7.5 (95% confidence interval = 2.3 to 25) when comparing equipment 1 year old with equipment epsilon 7 years old. The results of this study show that ascarid infections may re-emerge following a change to alternative housing. With the impending ban on conventional battery cages in the member states of the European Union, ascarid infections are likely to increase in importance and efficient control options such as hygiene barriers should be implemented on all farms.
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| 4. |
- Jansson, Desirée, et al.
(författare)
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Northern fowl mite (Ornithonyssus sylviarum) in Sweden
- 2014
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Ingår i: Medical and Veterinary Entomology. - : Wiley. - 0269-283X .- 1365-2915. ; 28:4, s. 443-446
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Tidskriftsartikel (refereegranskat)abstract
- Haematophagous mites were collected from the vent region and plumage of chickens in six hobby flocks of ornamental breeds in Sweden, one of which included turkeys. Soiled vent skin and feathers, dermatitis, hyperkeratosis, skin necroses and ulcers were observed in 12 necropsied birds from two of the flocks. The mites were identified as the northern fowl mite Ornithonyssus sylviarum (Mesostigmata: Macronyssidae). This was supported by sequence analysis of a 642-bp region in the mitochondrial cytochrome oxidase subunit 1 (COI) gene (COI) in mites collected from five flocks, which showed 97–99% sequence similarity to O. sylviarum by blast analysis. Pairwise sequence comparisons revealed nucleotide variations in the range of 0–2.8%, whereas amino acid sequences were highly conserved. This paper represents one of very few records of O. sylviarum in European poultry, and is the first to report COI sequence data for O. sylviarum from poultry in Europe.
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| 5. |
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| 6. |
- Martis, Mihaela-Maria, et al.
(författare)
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RNA-Seqde novo assembly and differential transcriptome analysis of the nematode Ascaridia galli in relation to in vivo exposure to flubendazole
- 2017
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Ingår i: PLOS ONE. - : PUBLIC LIBRARY SCIENCE. - 1932-6203. ; 12:11
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Tidskriftsartikel (refereegranskat)abstract
- The nematode Ascaridia galli (order Ascaridida) is an economically important intestinal parasite responsible for increased food consumption, reduced performance and elevated mortality in commercial poultry production. This roundworm is an emerging problem in several European countries on farms with laying hens, as a consequence of the recent European Union (EU) ban on conventional battery cages. As infection is associated with slow development of low levels of acquired protective immunity, parasite control relies on repeated use of dewormers (anthelmintics). Benzimidazoles (BZ) are currently the only anthelmintic registered in the EU for use in controlling A. galli and there is an obvious risk of overuse of one drug class, selecting for resistance. Thus we developed a reference transcriptome of A. galli to investigate the response in gene expression before and after exposure to the BZ drug flubendazole (FLBZ). Transcriptional variations between treated and untreated A. galli showed that transcripts annotated as mitochondrial glutamate dehydrogenase and cytochrome P450 were significantly down-regulated in treated worms, whereas transcripts homologous to heat shock proteins (HSP), catalase, phosphofructokinase, and a multidrug resistance Pglycoprotein (PGP1) were significantly up-regulated in treated worms. Investigation of candidate transcripts responsible for anthelmintic resistance in livestock nematodes led to identification of several tubulins, including six new isoforms of beta-tubulin, and several ligandgated ionotropic receptors and ABC-transporters. We discovered several transcripts associated with drug binding and processing genes, but further characterisation using a larger set of worms exposed to BZs in functional assays is required to determine how these are involved in drug binding and metabolism.
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| 7. |
- Tarbiat, Behdad, et al.
(författare)
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A novel duplex ddPCR assay for detection and differential diagnosis of Ascaridia galli and Heterakis gallinarum eggs from chickens feces
- 2021
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Ingår i: Veterinary Parasitology. - : Elsevier BV. - 0304-4017 .- 1873-2550. ; 296
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Tidskriftsartikel (refereegranskat)abstract
- Since the EU ban on battery cages, many studies have listed Ascaridia galli and Heterakis gallinarum as the most common roundworms in the European laying hen population. A complicating factor is that the eggs of these parasites are almost identical. Thus, lack of molecular diagnostic approaches has driven epidemiological studies to take on necropsy for species discrimination, which is labor and cost intensive. Here, we describe a novel diagnostic tool based on droplet digital PCR for simultaneous identification and absolute quantification of the eggs of both of these ascarids in chickens' droppings using two different genus-specific primer-probe sets targeting the second internal transcribed spacer region (ITS-2) in the nuclear ribosomal (rRNA) gene array. No cross-reaction was observed when different combinations of DNA and species-specific primers and probes were tested. The lowest obtained frequency threshold for the detection of H. gallinarum in the presence of a constant A. galli DNA concentration was determined to be 0.8 %. After validation, we used the assay to analyze field samples collected from several Swedish laying hen farms. Out of 134 samples, 86 (64 %) were positive for A. galli while 11 (8.3 %) samples were positive for H. gallinarum. These samples were initially analyzed with flotation technique for detection of ascarid eggs. The results of the Cohen's kappa indicated substantial agreement (85.8 %) between the two tests. In conclusion, we have validated a novel molecular-based diagnostic tool for quantification and differentiation between intestinal parasites of major importance in chickens with high precision. Although this study focuses on identification of parasites of laying hens, the findings may well have a bearing on all types of chicken production systems. The present study lays the groundwork for future research into epidemiology of these two important chicken parasite species.
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| 8. |
- Tarbiat, Behdad, et al.
(författare)
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Comparison between anthelmintic treatment strategies against Ascaridia galli in commercial laying hens
- 2016
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Ingår i: Veterinary Parasitology. - : Elsevier BV. - 0304-4017 .- 1873-2550. ; 226, s. 109-115
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Tidskriftsartikel (refereegranskat)abstract
- The efficacy of a sustainable deworming strategy based on targeted treatments (TT) against Ascaridia galli was investigated for the first time in laying hen flocks on a Swedish commercial farm. Three experimental protocols with different levels of treatment, e.g. targeted treatment (TT), conventional treatment (CT) and untreated (UT), were tested in randomly allocated flocks of two different bird hybrids. Every second week faecal egg counts (FECs) were determined from pooled faecal materials collected on trays (20 x 27 cm) placed for a maximum of 12 h on the litter belts. In the TT, anthelmintic administration (fenbendazole, 1 mg/kg body weight for 5 days) started at 22 weeks post placement (wpp) and was repeated twice when the pooled FECs surpassed the assigned threshold of 200 egg per gram faeces (EPG). The CT flocks were treated once at 27 wpp using the same anthelmintic. Hens in the UT were not dewormed and served as controls. Additionally, FECs on cloacal contents, worm fecundity and worm burdens were determined at 19, 35 and 45 wpp. None of the flocks became infected until after 16 wpp. The cumulative pooled FECs at the end of the study were significantly (p < 0.01) lower in the TT compared to both CT and UT. Although repeated treatment in the TT protocol did not affect the fecundity, a worm density-dependent increase in fecundity was observed. Cloacal FECs and the number of adult A. galli in TT at 35 and 45 wpp were significantly lower compared to other flocks. This study provides evidence that the TT strategy is better in terms of lower worm burden and decreased cumulative environmental parasite egg numbers compared to CT strategy. The TT strategy should be considered as an alternative to the CT strategy with regard to A. galli control in commercial laying hens. (C) 2016 Elsevier B.V. All rights reserved.
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| 9. |
- Tarbiat, Behdad, et al.
(författare)
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Developmental capacity of Ascaridia galli eggs is preserved after anaerobic storage in faeces
- 2018
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Ingår i: Veterinary Parasitology. - : Elsevier BV. - 0304-4017 .- 1873-2550. ; 255, s. 38-42
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Tidskriftsartikel (refereegranskat)abstract
- The reliability of the results of in vitro studies such as detection of anthelmintic resistance often depends on the ability of the parasite eggs to develop under laboratory conditions. The aim of this study was to assess the embryonation capability of the chicken roundworm Ascaridia galli eggs after storage under different conditions. Two storage media for parasite eggs were used; faeces or water. Eggs in petri dishes (90 dishes in total) containing faces or water media were first exposed either to aerobic or anaerobic conditions at different temperatures (4 degrees C / + O-2, 4 degrees C / -O-2, 25 degrees C / -O-2) for a maximum of 72 days. Every second week, materials from petri dishes in triplicates were recovered and incubated aerobically for two weeks at 25 degrees C. After the incubation, 200-300 eggs from each petri shish (sampling unit) were counted and the number of embryonated eggs was determined. Data was analyzed in R (version 3.4.3) A logistic regression model with the probability of an egg to embryonate as dependent variable and conditions, storage medium and time points as fixed effects with quasibinomial distribution was run. Least-square means were calculated and pairwise comparisons were made with the fixed effect factors (condition, storage medium and time point). Eggs in faeces had a significantly (p < 0.05) higher embryonation than those in water, irrespective of storage conditions. At 4 degrees C embryonation tended to decline over time under aerobic conditions irrespective of the storage medium, whereas it remained constant following storage at anaerobic conditions. In contrast, anaerobic storage at the 25 degrees C negatively affected egg development in both media, except for day 14 in faeces. Our major finding was that eggs in faeces under anaerobic conditions and at 4 degrees C retained the highest rate of development, with a minimum decline in their developmental capacity over time compared to cleaned eggs stored in water.
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| 10. |
- Tarbiat, Behdad, et al.
(författare)
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Effect of a targeted treatment strategy against Ascaridia galli on egg production, egg quality and bird health in a laying hen farm
- 2020
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Ingår i: Veterinary Parasitology. - : Elsevier BV. - 0304-4017 .- 1873-2550. ; 286
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Tidskriftsartikel (refereegranskat)abstract
- Worm control is an important aspect of the successful management of the egg production industry. Of particular concern is Ascaridia galli, which at high parasite loads affect health and production in layers. Application of a targeted treatment strategy (TT) to control A. galli has shown promise. The purpose of this study was to explore the effect of such a strategy on welfare indicators and production performance of layers. Six flocks (F1-6) on a commercial farm were allocated to three treatment groups. Flocks Fl and F4 were treated (TT) with fenbendazole at 22, 27 and 36 weeks post-placement (WPP). Flocks F2 and F5 were treated at 27 WPP (conventional treatment, CT) and hens in flocks F3 and F6 served as untreated (UT) control groups. At 19, 35 and 45 WPP twenty-five hens plus thirty eggs per flock were randomly selected. Hens were weighed and their plumage conditions (PC) were assessed. The eggs were subjected to various external and interior quality analyses. Production data such as number of eggs/hen/week, egg mass and feed conversion ratio (FCR) were calculated from raw data obtained from all flocks on a weekly basis. The number of eggs/hen/week, egg mass and FCR were higher (P < 0.05) in the TT flocks and hens had better PC both at 35 and 45 WPP compared with other flocks. No differences in body weight and physical egg quality were observed between groups except for egg shell strength which was higher (P < 0.05) in the CT flocks. These data suggest that better production performance and plumage, which suggests improved health, can be achieved through the application of a TT strategy. The insights gained from this research should help to justify the extra cost and labor associated with the TT strategy.
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