Effects of air quality on chicken health

Houses for intensive poultry production likely contain very high concentrations of airborne contaminants that may negatively affect human and animal health. However, very little is known of the relations between concentrations, size, nature and composition of airborne particles on animal health in intensive livestock housing. Also, mechanisms of responses of animals to unhygienic conditions such as airborne particles, and adaptation responses are unknown. It is likely that animals under high pressure for production such as broiler chickens may be affected severely by continuous antigenic stimulation. Accordingly, the aim of this thesis was to determine effects of airborne dust and its components, and particle size, respectively on the immune system of broilers, and consequently disease resistance and performance (in this case growth). The objectives were to address 1) dust concentrations and particle size distribution present in counts and in mass inside (and around) animal houses; 2) whether dust or its components (with emphasis on pathogen associated molecular patterns or PAMP) affect the immune competence and specific immune response of broilers after challenge via the respiratory tract at different ages; 3) whether broilers may adapt to respiratory challenge with dust and its different components, and particle size; 4) whether dust and its components including particle size affect growth (and heart parameters) of broilers; and finally 5) localization of 1 µm and 10 µm (fluorescent-labelled polystyrene) particles as a model for localization and transport of dust particles in the body of broilers after challenge via the respiratory route In terms of mass, the dust concentration in poultry houses was generally higher than in pig houses, cattle houses, and mink houses. Mass concentrations of PM10 (particles with aerodynamic diameter smaller than 10 µm) was 0.83 to 4.60 mg m-3 in poultry houses, 0.13 to 1.62 mg m-3 in pigs farms, and 0.02 to 0.12 mg m-3 in cattle and mink farms. In counts, most particles (92%) inside were found smaller than 2.5 µm, whereas these particles only contributed for 2.6% to mass. Fine dust and coarse dust collected from broiler houses also affected specific antibody responses to a model antigen (HuSA), either declining or enhancing, depending on age of challenge and isotype measured. Components known to be part of dust and with known or expected immunologically mediating features like lipopolysaccharide (LPS), β-glucan, lipoteichoic acid, chitin, NH3, heat-dust, respectively, were used to intratracheally challenge broilers at 3 and 7 weeks of age. Especially LPS and β-glucan enhanced immune responses, but depressed body weight gain of the broilers after primary and secondary challenge. LPS also enhanced antigen-specific responses at various ages, even when administered 4 weeks prior to the antigen. After intratracheal (and also cloacal) challenge, fluorescent-labelled polystyrene beads from two sizes (1 µm and 10 µm) were present in all tissues from the broiler studied during at least one week. Such beads might have been taken up by phagocytic cells or were transferred via the blood stream. It was concluded that airborne particles in different sizes and with different components could alert the immune system of broilers as exemplified by enhanced primary responses in an antigen- nonspecific fashion. The absence of major effects of dust components on secondary immune responses on the other hand may indicate a regulating role of dust components on the immune system. Dust (components), however, had an important negative impact on body weight gain and heart parameters. It is concluded that there are relationships between hygienic conditions in broiler houses and immune mediated health, and as a consequence likely disease resistance and/or sensitivity to vaccination and other health management procedures. The current study urges further studies on the presence (and identification) and consequences of airborne constituents to protect health of poultry.</p

Source identification and quantification of particulate matter emitted from livestock houses

There is need to identify and quantify the contribution of different sources to airborne particulate matter (PM) emissions from animal houses. To this end, we compared the chemical and morphological characteristics of fine and coarse PM from known sources collected from animal houses with the characteristics of on-farm fine and coarse airborne PM using two methods: classification rules based on decision trees and multiple linear regression. Fourteen different farms corresponding to seven different housing systems for poultry and pigs were sampled during winter. A total of 28 fine and 28 coarse on-farm airborne PM samples were collected, together with a representative sample of each known source per farm (56 known source samples in total). Source contributions were calculated as relative percentage contributions in particle numbers and then estimated in particle mass. Based on particle numbers, results showed that in poultry houses, most on-farm airborne PM originated from feathers (ranging from 4% to 43% in fine PM and from 6% to 35% in coarse PM) and manure (ranging from 9% to 85% in fine PM and from 30% to 94% in coarse PM). For pigs, most on-farm airborne PM originated from manure (ranging from 70% to 98% in fine PM and from 41% to 94% in coarse PM). Based on particle mass, for poultry most on-farm airborne PM still originated from feathers and manure; for pigs, however, most PM originated from skin and manure. Feed had a negligible contribution to on-farm airborne PM compared with other sources. Results presented in this study improve the understanding of sources of PM in different animal housing systems, which may be valuable when choosing optimal PM reduction technique

Effects of air quality on chicken health

Houses for intensive poultry production likely contain very high concentrations of airborne contaminants that may negatively affect human and animal health. However, very little is known of the relations between concentrations, size, nature and composition of airborne particles on animal health in intensive livestock housing. Also, mechanisms of responses of animals to unhygienic conditions such as airborne particles, and adaptation responses are unknown. It is likely that animals under high pressure for production such as broiler chickens may be affected severely by continuous antigenic stimulation. Accordingly, the aim of this thesis was to determine effects of airborne dust and its components, and particle size, respectively on the immune system of broilers, and consequently disease resistance and performance (in this case growth). The objectives were to address 1) dust concentrations and particle size distribution present in counts and in mass inside (and around) animal houses; 2) whether dust or its components (with emphasis on pathogen associated molecular patterns or PAMP) affect the immune competence and specific immune response of broilers after challenge via the respiratory tract at different ages; 3) whether broilers may adapt to respiratory challenge with dust and its different components, and particle size; 4) whether dust and its components including particle size affect growth (and heart parameters) of broilers; and finally 5) localization of 1 µm and 10 µm (fluorescent-labelled polystyrene) particles as a model for localization and transport of dust particles in the body of broilers after challenge via the respiratory route In terms of mass, the dust concentration in poultry houses was generally higher than in pig houses, cattle houses, and mink houses. Mass concentrations of PM10 (particles with aerodynamic diameter smaller than 10 µm) was 0.83 to 4.60 mg m-3 in poultry houses, 0.13 to 1.62 mg m-3 in pigs farms, and 0.02 to 0.12 mg m-3 in cattle and mink farms. In counts, most particles (92%) inside were found smaller than 2.5 µm, whereas these particles only contributed for 2.6% to mass. Fine dust and coarse dust collected from broiler houses also affected specific antibody responses to a model antigen (HuSA), either declining or enhancing, depending on age of challenge and isotype measured. Components known to be part of dust and with known or expected immunologically mediating features like lipopolysaccharide (LPS), β-glucan, lipoteichoic acid, chitin, NH3, heat-dust, respectively, were used to intratracheally challenge broilers at 3 and 7 weeks of age. Especially LPS and β-glucan enhanced immune responses, but depressed body weight gain of the broilers after primary and secondary challenge. LPS also enhanced antigen-specific responses at various ages, even when administered 4 weeks prior to the antigen. After intratracheal (and also cloacal) challenge, fluorescent-labelled polystyrene beads from two sizes (1 µm and 10 µm) were present in all tissues from the broiler studied during at least one week. Such beads might have been taken up by phagocytic cells or were transferred via the blood stream. It was concluded that airborne particles in different sizes and with different components could alert the immune system of broilers as exemplified by enhanced primary responses in an antigen- nonspecific fashion. The absence of major effects of dust components on secondary immune responses on the other hand may indicate a regulating role of dust components on the immune system. Dust (components), however, had an important negative impact on body weight gain and heart parameters. It is concluded that there are relationships between hygienic conditions in broiler houses and immune mediated health, and as a consequence likely disease resistance and/or sensitivity to vaccination and other health management procedures. The current study urges further studies on the presence (and identification) and consequences of airborne constituents to protect health of poultry

Effects of 2 size classes of intratracheally administered airborne dust particles on primary and secondary specific antibody responses and body weight gain of broilers: A pilot study on the effects of naturally occurring dust

We studied the effects of a concurrent challenge on slow-growing broilers with 1) airborne particles of 2 sizes: fine dust (smaller than 2.5 microns) and coarse dust (between 2.5 and 10 microns) that were directly collected from a broiler house and 2) lipopolysaccharide on intratracheal immunizations with the specific antigen human serum albumin (HuSA) and measured primary and secondary systemic (total) antibody responses and (isotype-specific) IgM, IgG, and IgA responses at 3 and 7 wk of age. All treatments affected immune responses at several ages, heart morphology, and BW gain, albeit the latter only temporarily. Dust particles significantly decreased primary antibody (IgT and IgG) responses to HuSA at 3 wk of age but enhanced IgM responses to HuSA at 7 wk of age. Dust particles decreased secondary antibody responses to HuSA, albeit not significantly. All of the birds that were challenged with dust particles showed decreased BW gain after the primary but not after the secondary challenge. Relative heart weight was significantly decreased in birds challenged with coarse dust, fine dust, lipopolysaccharide, and HuSA at 3 wk of age, but not in birds challenged at 7 wk of age. Morphology (weight, width, and length) of hearts were also affected by the dust challenge at 3 wk of age. The present results indicate that airborne dust particles obtained from a broiler house when intratracheally administered at an early age affect specific humoral immune responsiveness and BW gain of broilers to simultaneously administered antigens differently than when administered at a later age. The hygienic status of broiler houses at a young age may be of importance for growth and immune responsiveness, and consequently, for vaccine efficacy and disease resistance in broilers. The consequences of our findings are discussed

Deeltjesgrootteverdeling en bronnen van stof in stallen : [samenvattende rapportage]

In dit rapport wordt de deeltjesgrootteverdeling van stof en de bijdrage van verschillende bronnen aan stof in stallen gekwantificeerd. Voor de belangrijkste combinaties van diercategorieën en stalsystemen is onderzocht hoe de stofdeeltjes over de verschillende diameter-klassen zijn verdeeld en welke bronnen in de stal bijdragen tot de vorming van fijn stof

Effects of repeated intratracheally administered lipopolysaccharide on primary and secondary specific antibody responses and on body weight gain of broilers

Earlier, we reported that pathogen-associated molecular patterns such as lipopolysaccharide (LPS), when administered intratracheally (i.t.), affected primary and secondary specific antibody responses to antigens administered concurrently, either i.t. or systemically, and also affected BW gain (BWG) of layers and broilers. In the present study, we evaluated the effects of repeated i.t. challenge with LPS concurrently with or before i.t. immunizations with the specific antigens human serum albumin (HuSA) and rabbit gamma globulin (RGG) on primary (HuSA, RGG) and secondary (HuSA) systemic antibody responses and (isotype) IgM and IgG responses at 2 different ages. Broilers were challenged via the trachea at 3 and 7 wk of age with various combinations of LPS, HuSA, and RGG. All treatments affected immune responses at several time points and also affected BWG, albeit temporarily for the latter. Lipopolysaccharide enhanced primary antibody responses to HuSA and to RGG, when challenged concurrently, but birds challenged solely with LPS at 3 wk of age also showed enhanced primary antibody responses to HuSA and RGG given at 7 wk of age. This was true for IgM as well as IgG isotype responses. Lipopolysaccharide challenge negatively affected BWG at 3 wk of age, whereas the negative effects of LPS after a secondary LPS challenge at 7 wk of age were most pronounced in the birds challenged with LPS at 3 wk of age. The present results indicated that LPS, when administered i.t. at a young age, may affect specific humoral immune responsiveness to antigens administered simultaneously and to BWG of broilers, but also when challenged 4 wk later with specific antigens, suggesting an enhanced status of immune reactivity or sensitivity. The hygienic status of broiler houses at a young age may thus influence BWG, immune responsiveness, and, consequently, the vaccine efficacy and disease resistance in broilers at later ages. The consequences of our findings are discussed

Deeltjesgrootteverdeling en bronnen van stof in stallen : [samenvattende rapportage]

In dit rapport wordt de deeltjesgrootteverdeling van stof en de bijdrage van verschillende bronnen aan stof in stallen gekwantificeerd. Voor de belangrijkste combinaties van diercategorieën en stalsystemen is onderzocht hoe de stofdeeltjes over de verschillende diameter-klassen zijn verdeeld en welke bronnen in de stal bijdragen tot de vorming van fijn stof

Source identification and quantification of particulate matter emitted from livestock houses

There is need to identify and quantify the contribution of different sources to airborne particulate matter (PM) emissions from animal houses. To this end, we compared the chemical and morphological characteristics of fine and coarse PM from known sources collected from animal houses with the characteristics of on-farm fine and coarse airborne PM using two methods: classification rules based on decision trees and multiple linear regression. Fourteen different farms corresponding to seven different housing systems for poultry and pigs were sampled during winter. A total of 28 fine and 28 coarse on-farm airborne PM samples were collected, together with a representative sample of each known source per farm (56 known source samples in total). Source contributions were calculated as relative percentage contributions in particle numbers and then estimated in particle mass. Based on particle numbers, results showed that in poultry houses, most on-farm airborne PM originated from feathers (ranging from 4% to 43% in fine PM and from 6% to 35% in coarse PM) and manure (ranging from 9% to 85% in fine PM and from 30% to 94% in coarse PM). For pigs, most on-farm airborne PM originated from manure (ranging from 70% to 98% in fine PM and from 41% to 94% in coarse PM). Based on particle mass, for poultry most on-farm airborne PM still originated from feathers and manure; for pigs, however, most PM originated from skin and manure. Feed had a negligible contribution to on-farm airborne PM compared with other sources. Results presented in this study improve the understanding of sources of PM in different animal housing systems, which may be valuable when choosing optimal PM reduction technique

Particulate matter emitted from poultry and pig houses: source identification and quantification

There is need to identify and quantify the contribution of different sources to airborne particulate matter (PM) emissions from animal houses. To this end, we compared the chemical and morphological characteristics of fine and coarse PM from known sources collected from animal houses with the characteristics of on-farm fine and coarse airborne PM using two methods: classification rules based on decision trees and multiple linear regression. Fourteen different farms corresponding to seven different housing systems for poultry and pigs were sampled during winter. A total of 28 fine and 28 coarse on-farm airborne PM samples were collected, together with a representative sample of each known source per farm (56 known source samples in total). Source contributions were calculated as relative percentage contributions in particle numbers and then estimated in particle mass. Based on particle numbers, results showed that in poultry houses, most on-farm airborne PM originated from feathers (ranging from 4% to 43% in fine PM and from 6% to 35% in coarse PM) and manure (ranging from 9% to 85% in fine PM and from 30% to 94% in coarse PM). For pigs, most on-farm airborne PM originated from manure (ranging from 70% to 98% in fine PM and from 41% to 94% in coarse PM). Based on particle mass, for poultry most on-farm airborne PM still originated from feathers and manure; for pigs, however, most PM originated from skin and manure. Feed had a negligible contribution to on-farm airborne PM compared with other sources. Results presented in this study improve the understanding of sources of PM in different animal housing systems, which may be valuable when choosing optimal PM reduction technique