Abel, Hansjörg

[["dc.bibliographiccitation.firstpage","606"],["dc.bibliographiccitation.issue","3-4"],["dc.bibliographiccitation.journal","Veterinary Parasitology"],["dc.bibliographiccitation.lastpage","618"],["dc.bibliographiccitation.volume","205"],["dc.contributor.author","Das, Guerbuez"],["dc.contributor.author","Abel, Hansjoerg"],["dc.contributor.author","Savas, Turker"],["dc.contributor.author","Sohnrey, Birgit"],["dc.contributor.author","Gauly, Matthias"],["dc.date.accessioned","2018-11-07T09:33:37Z"],["dc.date.available","2018-11-07T09:33:37Z"],["dc.date.issued","2014"],["dc.description.abstract","In modern husbandry systems, feed rations for laying hens may contain high levels of dietary fibre, which may only be fermented intestinally. Depending on fermentation properties, the type of dietary fibre may influence the intra-caecal environment constituting the predilection site of Heterakis gallinarum. We investigated egg production dynamics and fecundity of H. gallinarum residing in different caecal environments induced through different types of dietary fibre. Growing layers were fed a standard (CON) or an insoluble(I-) or soluble- (S-) non-starch polysaccharides-(NSP) supplemented diet for the first 11 weeks (wk) of life in a twice-replicated experiment. At 3 wk of age, the birds were infected with 200 embryonated eggs of H. gallinarum. Starting from 3 wk post-infection (p.i.), individual daily total excreta were collected. The number of eggs per gram of faeces (EPG) was determined (N = 2240), and the number of eggs per day (EPD) were estimated. The birds were necropsied 8 wk p.i. and the worm burdens were quantified. The nematode began to lay eggs as early as 23 d.p.i. and thereafter laid on average 436 eggs/d. I-NSP- and S-SNP-supplemented diets expedited the onset of patency by approximately 5 days, and increased total egg excretion by 110% and 185%, respectively, due to higher worm counts. The latter diet (S-SNP) additionally increased total egg excretion by 94% due to enhanced fecundity. Longitudinally collected data showed that fecundity of the nematode (EPD/female) was relatively stable starting from the second week of the patent phase. Results suggest that NSP-induced enlargement of caeca favoured establishment of the nematode while effects of an intensified microbial fermentation through S-NSP were crucial for an enhancement in the worm fecundity. Based on the long-term data obtained from daily collections of total excreta in experimentally H. gallinarum-infected chickens, it is concluded that a diet enriched with pea bran as source of insoluble NSP increased worm egg production merely through elevated worm counts, whereas a diet supplemented with chicory root meal as source of soluble NSP elevated worm egg production through both increased worm counts, and more profoundly through enhanced fecundity. (C) 2014 Elsevier B.V. All rights reserved."],["dc.identifier.doi","10.1016/j.vetpar.2014.08.008"],["dc.identifier.isi","000344425200025"],["dc.identifier.pmid","25200385"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/32007"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Elsevier Science Bv"],["dc.relation.issn","1873-2550"],["dc.relation.issn","0304-4017"],["dc.title","Egg production dynamics and fecundity of Heterakis gallinarum residing in different caecal environments of chickens induced by fibre-rich diets"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","215"],["dc.bibliographiccitation.issue","3"],["dc.bibliographiccitation.journal","Archives of Animal Nutrition"],["dc.bibliographiccitation.lastpage","226"],["dc.bibliographiccitation.volume","66"],["dc.contributor.author","Seip, Katharina"],["dc.contributor.author","Breves, Gerhard"],["dc.contributor.author","Isselstein, Johannes"],["dc.contributor.author","Das, Guerbuez"],["dc.contributor.author","Abel, Hansjoerg"],["dc.date.accessioned","2018-11-07T09:15:23Z"],["dc.date.available","2018-11-07T09:15:23Z"],["dc.date.issued","2012"],["dc.description.abstract","The investigation aimed at examining if the composition of grassland silage affects the microbial nitrogen assimilation in the rumen of sheep. The silages were made of vegetative summer re-growths consisting of 48% grasses, 28% legumes and 24% other forbs (GCF) or of pure grass (G). Silage GCF contained more intermediately degradable non-structural and less slowly degradable carbohydrates, more crude protein (CP), a narrower ratio between slow and very slow degradable nitrogen (N), and exhibited higher in situ degradability of organic matter and CP than Silage G. Four adult wethers equipped with rumen fistulae were used in a two factorial trial. Feed was offered either as silage alone or as a mixture of silage and barley (60: 40). Microbial N was estimated using continuous intraruminal N-15 infusion and measurement of N-15-enrichment in microbes isolated from rumen liquor samples. With the exception of trends for ruminal butyrate concentrations, no interactions were detected between silage and barley feeding. Sheep receiving Silage GCF exhibited larger diurnal fluctuations of ammonia, and produced more microbial N (p < 0.05) than sheep on Silage G. Feeding the silages with barley decreased ruminal pH and elevated the concentrations of butyrate (p < 0.05). The 15 N incorporation into microbial N was reduced by barley feeding (p < 0.05) along with a trend to accelerated rumen fluid turnover, resulting in similar microbial N yields as found in sheep receiving silage without barley. It is concluded that the larger and better balanced amounts of intermediately degradable carbohydrate-and N-containing fractions favoured the ruminal microbial protein synthesis in sheep consuming Silage GCF instead of Silage G."],["dc.identifier.doi","10.1080/1745039X.2012.676815"],["dc.identifier.isi","000303818300004"],["dc.identifier.pmid","22724167"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/27671"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Taylor & Francis Ltd"],["dc.relation.issn","1745-039X"],["dc.title","Ruminal fermentation characteristics and microbial nitrogen assimilation in sheep fed differently composed grass silages"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","121"],["dc.bibliographiccitation.issue","1-2"],["dc.bibliographiccitation.journal","Veterinary Parasitology"],["dc.bibliographiccitation.lastpage","128"],["dc.bibliographiccitation.volume","178"],["dc.contributor.author","Das, Guerbuez"],["dc.contributor.author","Abel, Hansjoerg"],["dc.contributor.author","Rautenschlein, Silke"],["dc.contributor.author","Humburg, Julia"],["dc.contributor.author","Schwarz, Anna"],["dc.contributor.author","Breves, Gerhard"],["dc.contributor.author","Gauly, Matthias"],["dc.date.accessioned","2018-11-07T08:56:00Z"],["dc.date.available","2018-11-07T08:56:00Z"],["dc.date.issued","2011"],["dc.description.abstract","It was hypothesized that the establishment and fecundity of Histomonas meleagridis free Heterakis gallinarum may be affected by dietary non-starch polysaccharides (NSPs). One-day-old female layer chicks (N = 670) were fed ad libitum for 11 wk one of the following diets in a three-times repeated experiment: basal diet (CON), basal diet plus pea bran rich in insoluble NSP (I-NSP), basal diet plus chicory root meal as a source of inulin rich soluble NSP (S-NSP). At the end of wk three, each feeding group was subdivided into an uninfected and an infected group of birds each being inoculated with a placebo or with 200 H. meleagridis free eggs of H. gallinarum. The birds were slaughtered 8 wk post infection and their worm burdens, the nematode egg excretion, caeca sizes and weights as well as intracaecal pH and volatile fatty acid (VFA) concentrations were determined. The NSP supplemented diets and also infection led to reduced body weights (BWs) of birds and impaired the feed conversion rate (P < 0.001). The NSP supplemented diets increased average length of caecum (P < 0.001) with S-NSP exerting a stronger effect than I-NSP (P < 0.05). Full caeca weight was increased by S-NSP (P < 0.001). Feeding S-NSP lowered intracaecal pH and molar proportion of acetate and increased that of butyrate compared to CON and I-NSP (P < 0.001). Caecal pool of VFA was increased with S-NSP (P < 0.001). The NSP-diets elevated incidence of infection (P < 0.01), average number of larvae (P < 0.009) and total worm burden (P < 0.001) compared to CON. The daily amount of faeces increased in NSP-fed birds (P < 0.001). Number of eggs per gram of faeces (EPG), number of eggs excreted per worm population of a bird within 24 h (EPD) and female worm fecundity (EPD/female worm) were elevated after feeding S-NSP (P <= 0.002), whereas I-NSP led to lower EPG/female worm (P < 0.05). The EPD increased in the sequence of CON < I-NSP < S-NSP (P < 0.001). It is concluded that the pea bran and chicory root meal used as sources of insoluble and soluble dietary NSPs, respectively, provided favourable conditions for the establishment of H. gallinarum in grower layers. Chicory root meal additionally enhanced fecundity of the nematode. Therefore, the two natural sources of insoluble and soluble NSPs offer no potential as protecting agents against H. gallinarum infections in chicken. (c) 2010 Elsevier B.V. All rights reserved."],["dc.description.sponsorship","German Research Foundation (DFG); Wilhelm Schaumann Foundation"],["dc.identifier.doi","10.1016/j.vetpar.2010.12.027"],["dc.identifier.isi","000291962200018"],["dc.identifier.pmid","21247704"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/23040"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Elsevier Science Bv"],["dc.relation.issn","1873-2550"],["dc.relation.issn","0304-4017"],["dc.title","Effects of dietary non-starch polysaccharides on establishment and fecundity of Heterakis gallinarum in grower layers"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","PII 938756233"],["dc.bibliographiccitation.firstpage","277"],["dc.bibliographiccitation.issue","3"],["dc.bibliographiccitation.journal","Avian Pathology"],["dc.bibliographiccitation.lastpage","287"],["dc.bibliographiccitation.volume","40"],["dc.contributor.author","Schwarz, Anna"],["dc.contributor.author","Gauly, Matthias"],["dc.contributor.author","Abel, Hansjoerg"],["dc.contributor.author","Das, Guerbuez"],["dc.contributor.author","Humburg, Julia"],["dc.contributor.author","Weiss, Alexander"],["dc.contributor.author","Breves, Gerhard"],["dc.contributor.author","Rautenschlein, Silke"],["dc.date.accessioned","2018-11-07T09:00:47Z"],["dc.date.available","2018-11-07T09:00:47Z"],["dc.date.issued","2011"],["dc.description.abstract","Little is known about the induction and modulation of gut-associated immune reactions after nematode infection in the chicken. The objective of the present study was to compare the pathogenesis, induction of immune reactions and electrophysiological changes of the gut after mono-infection with Heterakis gallinarum and after dual infection with H. gallinarum and Histomonas meleagridis in layer chickens. In two experiments 3-week-old chickens were inoculated with embryonated H. gallinarum eggs, which were positive for H. meleagridis. While birds of the first experiment were left untreated, those of the second experiment were treated with dimetridazol to prevent H. meleagridis co-infection. Mild to moderate histological lesions and local immune reactions with a significant increase in CD4+, CD8+, TCR+ and TCR+ cells in the lamina propria and induction of the T-helper type 2 (Th2) cytokine interleukin-13 dominated the H. gallinarum immune response at 2 weeks post infection. Co-infection with H. gallinarum and H. meleagridis induced an increase in mRNA expression of the T-helper type 1 (Th1) cytokine interferon-, a decrease in splenic CD4+ cells and severe destruction of the caecal mucosa in association with strong T-cell infiltration in the caecal lamina propria. There was no obvious effect on the chloride secretion of the caecal epithelium, which was investigated once the mucosa had almost recovered from the infection, in either experiment. These results suggest that the local T-cell reactions to nematode infections in chickens may be comparable with mammals and may be shifted from a Th2-dominated to a Th1-dominated response when accompanied by a protozoan infection."],["dc.identifier.doi","10.1080/03079457.2011.561280"],["dc.identifier.isi","000291806100007"],["dc.identifier.pmid","21711187"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/24252"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Taylor & Francis Ltd"],["dc.relation.issn","0307-9457"],["dc.title","Pathobiology of Heterakis gallinarum mono-infection and co-infection with Histomonas meleagridis in layer chickens"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","238"],["dc.bibliographiccitation.issue","3-4"],["dc.bibliographiccitation.journal","Veterinary Parasitology"],["dc.bibliographiccitation.lastpage","243"],["dc.bibliographiccitation.volume","170"],["dc.contributor.author","Das, Guerbuez"],["dc.contributor.author","Kaufmann, Falko"],["dc.contributor.author","Abel, Hansjoerg"],["dc.contributor.author","Gauly, Matthias"],["dc.date.accessioned","2018-11-07T08:42:11Z"],["dc.date.available","2018-11-07T08:42:11Z"],["dc.date.issued","2010"],["dc.description.abstract","The hypothesis examined in this study was that extra dietary lysine (Lys) above the recommended standard exerts beneficial effects on the defence reactions, growth performance and nutrient utilization in Ascaridia galli-infected chickens. Therefore, 1-day-old female Lohmann Selected Leghorn chickens were at first fed standard Lys diet (8.5g Lys/kg DM). At 4 weeks of age, the birds were allocated to groups 1 and 3, both being continued on standard Lys diet, whereas birds in groups 2 and 4 were switched to extra Lys diet (10.5g Lys/kg DM). Birds in groups 3 and 4 were additionally infected at this age (4 weeks) with 250 embryonated eggs of A. galli. All the birds were slaughtered 7-week-post-infection (p.i.) at an age of 11 weeks. Infected birds on standard Lys diet consumed more feed and reached a similar level of Lys intake as birds on extra Lys diet 7-week-p.i. Utilization of feed, crude protein, and Lys for body weight (BW) gain was adversely affected in infected birds on standard Lys diet (P < 0.001). Extra Lys diet reduced the incidence of infection (P < 0.05), but worm counts, worm length, faecal egg counts and female worm fecundity were not different between the infected groups (P > 0.05). Extra Lys diet led to higher final BW in uninfected and infected birds (P < 0.05). It is concluded that extra Lys above the normal recommended standard supports the defence reactions and compensates the negative effect of infection on growth performance and nutrient utilization in A. galli-infected birds. (C) 2010 Elsevier B.V. All rights reserved."],["dc.identifier.doi","10.1016/j.vetpar.2010.02.026"],["dc.identifier.isi","000279064500010"],["dc.identifier.pmid","20299150"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/19641"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Elsevier Science Bv"],["dc.relation.issn","0304-4017"],["dc.title","Effect of extra dietary lysine in Ascaridia galli-infected grower layers"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","208"],["dc.bibliographiccitation.issue","2-3"],["dc.bibliographiccitation.journal","Veterinary Parasitology"],["dc.bibliographiccitation.lastpage","216"],["dc.bibliographiccitation.volume","176"],["dc.contributor.author","Das, Guerbuez"],["dc.contributor.author","Abel, Hansjoerg"],["dc.contributor.author","Humburg, Julia"],["dc.contributor.author","Schwarz, Anna"],["dc.contributor.author","Rautenschlein, Silke"],["dc.contributor.author","Breves, Gerhard"],["dc.contributor.author","Gauly, Matthias"],["dc.date.accessioned","2018-11-07T08:58:12Z"],["dc.date.available","2018-11-07T08:58:12Z"],["dc.date.issued","2011"],["dc.description.abstract","Nutrition of the host animal may not only influence interactions between the host and its parasites, but also relations between different parasites species residing on the same host. We investigated effects of insoluble and soluble non-starch polysaccharides (NSP) on establishment and development of Heterakis gallinarum in chicken being treated or left untreated against Histomonas meleagridis. Six groups of one-day-old birds were allocated to three diets, two on each diet. The birds were fed ad libitum either a basal diet (CON), or CON + insoluble NSP (I-NSP) or CON + soluble NSP (S-NSP) until an age of 11 wk At an age of 19 d, one of each diet groups was prophylactically treated for 9 d with dimetridazole (0.05%, w/v) via drinking water against histomonas. The remaining three groups were left un-treated. Two days after starting dimetridazole treatment (at 3 wk), each of the 6 groups was divided into two sub-groups. One dimetridazole treated and one dimetridazole un-treated groups of birds on each diet (6 groups) were infected with 200 embryonated eggs of H. gallinarum that were previously harvested from histomonas-carrying H. gallinarum infected chickens. The remaining 6 groups of uninfected birds, either treated or left un-treated against H. meleagridis, served as controls. Worm burdens of infected birds were determined 8 wk p.i. Treatment against H. meleagridis significantly increased incidence of H. gallinarum infection and average worm length in all infected groups independent of the diet consumed (p<0.001). An interaction between effects of diet and dimetridazole treatment on worm burden (p<0.001) indicated that the S-NSP diet resulted in lowest worm burden in dimetridazole un-treated birds, whereas it caused the highest worm burden in the treated birds (p<0.05). Furthermore, the treatment resulted in higher worm burdens when compared to un-treated birds on the corresponding diets (p<0.05). Infection with H. gallinarum impaired body weight (BW) of the chicks (p<0.05) and H. meleagridis aggravated this effect (p<0.05). Dimetridazole treated and un-treated uninfected birds developed similar BW (p>0.05). Both NSP supplemented diets resulted in lower (p<0.05) BW when compared with the CON diet, S-NSP being inferior to I-NSP (p<0.05). It is concluded that H. meleagridis harms the definitive host as well as H. gallinarum. Both insoluble and soluble NSP supplemented diets favor H. gallinarum infection while S-NSP additionally intensifies histomonas infection, which then impairs establishment and development of H. gallinarum. (C) 2010 Elsevier B.V. All rights reserved."],["dc.description.sponsorship","German Research Foundation (DFG); H. Wilhelm Schaumann Foundation"],["dc.identifier.doi","10.1016/j.vetpar.2010.11.004"],["dc.identifier.isi","000289221400018"],["dc.identifier.pmid","21144662"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/23582"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Elsevier Science Bv"],["dc.relation.issn","0304-4017"],["dc.title","Non-starch polysaccharides alter interactions between Heterakis gallinarum and Histomonas meleagridis"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","163"],["dc.bibliographiccitation.issue","2"],["dc.bibliographiccitation.journal","Archives of Animal Nutrition"],["dc.bibliographiccitation.lastpage","173"],["dc.bibliographiccitation.volume","65"],["dc.contributor.author","Voelker, Denise"],["dc.contributor.author","Huether, Liane"],["dc.contributor.author","Das, Guerbuez"],["dc.contributor.author","Abel, Hansjoerg"],["dc.date.accessioned","2018-11-07T09:00:44Z"],["dc.date.available","2018-11-07T09:00:44Z"],["dc.date.issued","2011"],["dc.description.abstract","Based on repeatedly reported extensive pantothenic acid disappearance in the rumen, the present study is aimed at examining if pantothenic acid is used for a more efficient ruminal fermentation and microbial growth in an artificial rumen (Rusitec). Three substrates differing in roughage/concentrate ratio were incubated with and without the addition of Ca-D-pantothenate. Pantothenic acid was extensively degraded without notably influencing fermentation, microbial protein synthesis and the status of other B-vitamins such as riboflavin, vitamin B(6) and niacin. Therefore, pantothenic acid supplementation cannot be expected to contribute to microbial benefit for the ruminant animal."],["dc.description.sponsorship","Deutsche Forschungsgemeinschaft [Ab 30/7-1, Ab 30/7-2]"],["dc.identifier.doi","10.1080/1745039X.2011.552272"],["dc.identifier.isi","000288244200006"],["dc.identifier.pmid","21545081"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/24249"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Taylor & Francis Ltd"],["dc.relation.issn","1745-039X"],["dc.title","Pantothenic acid supplementation to support rumen microbes?"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","774"],["dc.bibliographiccitation.issue","7"],["dc.bibliographiccitation.journal","Developmental & Comparative Immunology"],["dc.bibliographiccitation.lastpage","784"],["dc.bibliographiccitation.volume","35"],["dc.contributor.author","Schwarz, Anna"],["dc.contributor.author","Gauly, Matthias"],["dc.contributor.author","Abel, Hansjoerg"],["dc.contributor.author","Das, Guerbuez"],["dc.contributor.author","Humburg, Julia"],["dc.contributor.author","Rohn, Karl"],["dc.contributor.author","Breves, Gerhard"],["dc.contributor.author","Rautenschlein, Silke"],["dc.date.accessioned","2018-11-07T08:54:54Z"],["dc.date.available","2018-11-07T08:54:54Z"],["dc.date.issued","2011"],["dc.description.abstract","Gastro-intestinal nematode infections in mammals are associated with local T lymphocyte infiltrations, Th2 cytokine induction, and alterations in epithelial cell secretion and absorption. This study demonstrates that Ascaridia (A.) galli infection in chicken also elicits local gut-associated immune reactions and changes in the intestinal electrogenic nutrient transport. In A. galli-infected birds we observed infiltrations of different T cell populations in the intestinal lamina propria and accumulation of CD4+ lymphocytes in the epithelium. The Th2 cytokines IL-4 and IL-13 dominated the intestinal immune reactions following A. galli infection. A. gall-specific systemic IgY antibodies were detected after two weeks post infection, and did only poorly correlate with detected worm numbers. Electrogenic transport of alanin and glucose was impaired in A. galli-infected chicken. Our data provide circumstantial evidence that local immune responses and electro-physiological intestinal functions may be connected and contribute to the elimination of worm infection. (C) 2011 Elsevier Ltd. All rights reserved."],["dc.description.sponsorship","German research foundation (DFG) [AB 30/8-1, BR 780/14-1]"],["dc.identifier.doi","10.1016/j.dci.2011.02.012"],["dc.identifier.isi","000291071900008"],["dc.identifier.pmid","21382408"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/22781"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Elsevier Sci Ltd"],["dc.relation.issn","0145-305X"],["dc.title","Immunopathogenesis of Ascaridia galli infection in layer chicken"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","87"],["dc.bibliographiccitation.issue","1-2"],["dc.bibliographiccitation.journal","Veterinary Parasitology"],["dc.bibliographiccitation.lastpage","94"],["dc.bibliographiccitation.volume","183"],["dc.contributor.author","Das, Guerbuez"],["dc.contributor.author","Savas, Turker"],["dc.contributor.author","Kaufmann, Falko"],["dc.contributor.author","Idris, Ahmad"],["dc.contributor.author","Abel, Hansjoerg"],["dc.contributor.author","Gauly, Matthias"],["dc.date.accessioned","2018-11-07T08:48:45Z"],["dc.date.available","2018-11-07T08:48:45Z"],["dc.date.issued","2011"],["dc.description.abstract","This study investigated whether a precise and repeatable quantification of Heterakis gallinarum egg excretion, which considerably reflects the actual worm burdens, can be achieved based on collection of the daily total amount of faeces from chickens. Three-week-old birds (N = 64) were infected with 200 embryonated eggs of H. gallinarum, and placed into individual cages 3 wk after infection for 5 wk to collect daily faeces (N = 2240). The total daily faeces was mixed and a randomly taken sample per bird was analyzed to estimate the numbers of eggs per gram of faeces (EPG) and total number of eggs excreted within 24h (EPD). A total of 235 daily faecal collections were randomly selected and further examined to determine between and within sample variations of EPG counts as a measure of precision. For this, two random faecal samples were taken from the daily produced faeces by a bird, and the EPG was determined for each of the samples (EPG1 and EPG2). The second faecal sample was analyzed once more to determine a parallel EPG2 count (EPG2a) of the suspended sample. Precision of an EPG count was defined as its relative closeness to the average of two EPG counts using a relative asymmetry index (Index(EPG)). At an age of 11 wk, i.e. 8 wk p.i. the birds were slaughtered and their worm burdens were determined. There were no significant differences between EPG1 and EPG2 (P = 0.764) nor between EPG2 and EPG2a (P = 0.700), suggesting that the differences between or within the samples were not different from zero. Correlations between EPG counts, as between and within sample coherences, were r = 0.85 and r = 0.86, respectively. Precision of EPG counts, as measured by Index(EPG), was not influenced by consistency (P = 0.870) and total amount of faeces (P = 0.088). However, concentration of eggs in faeces (mean EPG) had a significant effect on the precision of the EPG counts (P < 0.001). Similar results were also observed for the within sample precision (Index(EPG2)). A segmented regression analysis indicated an abrupt change in the precision of EPG counts as the response to changing egg concentration in the examined faecal samples. The precision of analyses remarkably heightened up to a breakpoint with an EPG count of <= 617. A similar breakpoint was also determined for within sample precision (EPG2 <= 621). Moderate repeatabilities (R = 0.49) for EPG and EPD were estimated in the first week of egg excretion, whereas the estimates were higher (R = 0.67-0.84) in the following weeks. Correlations between number of female worms with daily measured EPG and EPD increased to an almost constant level (r >= 0.70; P < 0.05) in a few days after the nematode excreted eggs and predominantly remained so for the rest of the sampling period. It is concluded that mixing daily total faeces provides samples with random homogenous distribution of H. gallinarum eggs. Precision of the EPG counts increases as the egg concentration in faecal sample increases. Egg excretion of H. gallinarum, quantified either as EPG or EPD, is highly repeatable and closely correlated with the actual worm burden of birds starting as early as in 5th wk of infection. (C) 2011 Elsevier B.V. All rights reserved."],["dc.identifier.doi","10.1016/j.vetpar.2011.07.005"],["dc.identifier.isi","000298450400014"],["dc.identifier.pmid","21802853"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/21298"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Elsevier Science Bv"],["dc.relation.issn","0304-4017"],["dc.title","Precision, repeatability and representative ability of faecal egg counts in Heterakis gallinarum infected chickens"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]