title: Development and survival ofAscaris suumeggs in deep litter of pigs.
abstract: Indoor transmission ofAscaris suumpartly depends on the physico-chemical conditions in bedding material. Temperature, pH, aqueous ammonia, moisture, occurrence and development ofA. suumeggs were therefore compared in different areas (resting, intermediate and latrine) of two deep litter pens on an organic farm in four seasons. There was some variation, but mean ammonia levels were generally very low (1·0-2·6 mm) and pH levels were moderate (8·04-8·88) in all three areas. Relatively, resting areas were characterized by overall moderate moisture (36%) and moderately high temperature (35·7 °C) levels. The area contained few eggs (50 eggs g-1DM) of which 17% were viable, and though only 4% were larvated and 0·7% appeared infective, it was more than in the other areas. Intermediate areas had moderate moisture (43%) and high temperature (43·6 °C) levels. There were many eggs (523 eggs g-1DM), but overall viability was very low (5%) and few eggs were larvated (0·004%) or even infective (0·002%). Latrines typically had high moisture (79%) and moderate temperature (30 °C) levels. The concentration of eggs was very high (1444 egg g-1DM) and though 32% were viable, none had developed larval stages. The large majority ofA. suumeggs appear to die and only few become infective while in the deep litter. However, a large fraction of eggs may remain viable for some time and could thus contaminate agricultural land and develop to infectivity, if the manure is not composted appropriately.
authors.affiliation: Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark.
authors.forename: Kiran Kumar
authors.initials: KK
authors.lastname: Katakam
authors.affiliation: Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark.
authors.forename: Stig Milan
authors.initials: SM
authors.lastname: Thamsborg
authors.affiliation: Section for Veterinary Medicine, Danish Health and Medicines Authority, Copenhagen, Denmark.
authors.forename: Niels Christian
authors.initials: NC
authors.lastname: Kyvsgaard
authors.affiliation: Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark.
authors.forename: Anders
authors.initials: A
authors.lastname: Dalsgaard
authors.affiliation: Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark.
authors.forename: Helena
authors.initials: H
authors.lastname: Mejer
keywords: Ascaris suum eggs; ammonia; bedding material; deep litter; development; moisture; pH; temperature; viability