Heckendorn, F.; Häring, D.A.; Amsler, Z. and Maurer, V. (2009) Do stocking rate and a simple run management practice inﬂuence the infection of laying hens with gastrointestinal helminths? Veterinary Parasitology, 159 (1), pp. 60-68.
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The aim of this experiment conducted at four sites in Switzerland was to investigate the transmission and infectivity of the two main helminth parasite species of poultry (Ascaridia galli and Heterakis gallinarum) in outdoor runs with two different stocking rates.
Additionally, the inﬂuence of a simplemanagement practice (mowing of run) on helminth transmission was studied. Three run types were created on each site: runs C served as control (stocking rate 10 m2/hen, no management), runs B corresponded to runs C but were managed (10 m2/hen, management). In runs A stocking rates were doubled compared to control runs (5 m2/hen, no management). During two subsequent layer ﬂocks, a set of parasitological parameters (faecal egg counts (FECs), prevalence, worm burdens in hens and in tracer animals, helminth eggs in soil) as well as parameters describing the run vegetation were determined. The increased stocking rate (runs A) led to a larger proportion of bare soil and to a reduction of the average vegetation height. In runs with a lower stocking rate (B and C), the proportion of bare soil did not increase during the experimental period. Irrespective of the run type, numbers of helminth eggs in the soil decreased signiﬁcantly with an increasing distance to the hen houses, while the percentage of ground coverage as well as vegetation height increased. However, across runs the correlation between the percentage of ground cover and the values of eggs per gram soil between runs was very low (r2 = 0.0007, P = 0.95) indicating a non causal relationship. Signiﬁcant differences in FEC were found in ﬂock 2 (P < 0.001): FEC of hens in managed runs Bwere 24% lower (P < 0.05) than those of the control animals. Although not signiﬁcant, the corresponding prevalence was lower (-9.7%) in hens from managed runs as well. Hens from runs with a high stocking rate (A) had signiﬁcantly higher FEC than hens from control runs (C). In ﬂock 2 management (n.s.) and higher stocking rates (-62%, P < 0.05) decreased the worm burdens. Tracer animals from runs with a high stocking rate (A) had signiﬁcantly higher FEC than tracers from runs B and C in two tracer series. This was not reﬂected in the worm burdens. Overall, the stocking rate of hens in the outdoor run seemed not to inﬂuence the transmission patterns of A. galli and H. gallinarum and repeated mowing of runs did not reduce helminth infections. Lower stocking rates, however, led to a substantial improvement of the run vegetation.
|EPrint Type:||Journal paper|
|Keywords:||Tierhaltung, Veterinärparasitologie, Endoparasitenkontrolle, Prophylaxe QLIF, Legehennen, Auslaufmanagement|
|Subjects:|| Animal husbandry > Production systems > Poultry|
Animal husbandry > Health and welfare
|Research affiliation:|| Switzerland > FiBL - Research Institute of Organic Agriculture Switzerland > Veterinary Parasitology|
Switzerland > FiBL - Research Institute of Organic Agriculture Switzerland > Animal Husbandry and Breeding
|Deposited By:||Heckendorn F, biologist MSc|
|Deposited On:||16 Mar 2009|
|Last Modified:||09 Dec 2010 11:49|
|Refereed:||Peer-reviewed and accepted|
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