Effects of airborne particle on the immune system of broilers

HỌC VIỆN NÔNG NGHIỆP VIỆT NAM LAI THI LAN HUONG EFFECTS OF AIRBORNE PARTICLE ON THE IMMUNE SYSTEM OF BROILERS AGRICULTURAL UNIVERSITY PRESS - 2017 i INTRODUCTION 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 book is to determined 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 of this book 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 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 ii CONTENTS Chapter GENERAL INTRODUCTION Chapter SIZE DISTRIBUTION OF AIRBORNE PARTICLES IN ANIMAL HOUSES 15 Chapter EFFECTS OF DUST AND AIRBORNE-DUST-COMPONENTS ON ANTIBODY RESPONSES OF BROILERS 40 Chapter EFFECTS OF REPEATED INTRATRACHEALLY ADMINISTERED LIPOPOLYSACCHARIDE ON ANTIBODY RESPONSES OF BROILERS 62 Chapter A PILOT STUDY ON THE EFFECTS OF NATURALLY OCCURRING DUST IN BROILER 90 Chapter LOCALISATION AND QUANTIFICATION OF FLUORESCENT BEADS IN CHICKEN 115 iii Chapter GENERAL INTRODUCTION Poultry meat is high in protein and low in fat, is the second most widely eaten meat in the world, after pork, and accounts for 30% of world meat production (Raloff, 2003) In 2010, 81 million tons of poultry meat were delivered to the global market, with the US as leading producer, contributing 16.8 million tons (USDA, 2011) In the Netherlands, 103 million chickens were reared in 2010 on approximately 3000 chicken farms, which contributed 0.75 million tons of chicken meat to the market (CBS, 2011) Over the last decade intensive livestock production has contributed 2% to Dutch GDP; however, it contributed more than 15% to particulate matter (PM) emissions (Chardon and Van de Hoek, 2002) Intensive poultry production contributes over 50% to total PM emission from livestock production in the Europe (EMEP-CORINAIR., 2007) Besides the high PM emission rates, one of the main problems in intensive poultry production in temperate areas is the bad air quality in poultry houses, which is caused by low ventilation rates, especially in winter time Poultry houses have been found to have the highest dust concentrations of all livestock houses (Wathes et al., 1998) Dust production is especially high in floor systems with bedding Animal welfare legislation has led to a ban on cages, thereby enabling the birds to use perches and to dust bathe in bedding material These welfare demands probably affect air quality inside poultry houses This aspect of animal welfare, which could seriously affect animal health, is often ignored or given little attention Airborne dust in livestock houses may cause respiratory diseases in farmers and veterinarians (Andersen et al., 2004; Donham, 1993; Radon et al., 2001; Vogelzang et al., 1997) The dust in livestock houses has been characterized to some extent in terms of its concentration and its particle shape, particle size, density, and source (Cambra-Lopez et al., 2011a; 2011b) An airborne particle may contain many microorganisms such as bacteria, fungi, and viruses These particles can therefore spread animal and zoonotic diseases that may affect public health (Martin et al., 1996; Simecek et al., 1986; Seedorf et al., 1998) Furthermore, some components present in microorganisms can be very harmful for human and animal health The main harmful components in airborne dust that have been described are endotoxins, lipoteichoic acid (LTA), β-glucans (BGL), chitin, and ammonia; it is probable that more harmful dust components will be identified in due course Endotoxins or lipopolysaccharides (LPS) are components originating from the cell wall of gram-negative bacteria, LTA are components from gram-positive bacteria, BGL originate from fungi, chitin is derived from plants and arthropods, and ammonia from animal excreta Eduard et al (2009) have shown that intensive livestock farmers are at greater risk of respiratory morbidity and mortality Aerial gaseous pollutants, e.g ammonia and odorous compounds, are also found in dust particles and these compounds can also affect human and animal health (Al Homidan and Robertson, 2003, Bolhuis et al., 2003) Dust concentrations in animal houses are generally 10 to 100 times higher than concentrations in the outdoor environments (Zhang, 2004a) Concentrations of airborne dust have been measured in various studies (Cambra-López et al., 2009; Heber et al., 2006; Aarnink et al., 2004; Aarnink et al., 2011) Regarding intensive poultry production in closed housing systems, a study by Takai et al (1998) reported that mean dust concentrations in poultry houses were 0.45 mg m-3 for particles smaller than µm and 3.6 mg m-3 for particles smaller than 100 µm Airborne dust from animal houses is mainly comprised of organic matter (up to 90%); the rest is inorganic (Aarnink et al., 1999, Seedorf and Hartung, 2001) Organic dust originates from feedstuff, manure, bedding, animal skin, feathers, and microorganisms (Aarnink et al., 1999; Martin et al., 1996) The contribution of each of these sources depends on several factors, such as housing system, type of bedding material, ventilation system, and animal activity, and it varies, depending on dust particle size (Heber et al., 1988b; Takai et al., 1998; Donham et al., 1986) In poultry houses, airborne dust primarily originates from feathers and manure in the litter (Cambra-Lopez et al., 2011b) Muller and Wieser (1987) reported that airborne dust in a floor layer system mainly originated from bedding material in the litter Endotoxin (LPS) is one of the major components of organic dust in animal houses that affects health Endotoxins have proven to be harmful for farmers and their neighbours (Skorska et al., 2007; Muller et al., 2004; Schenker, 2004; Eduard et al., 2009) LPS is present in the outer membrane of gram-negative bacteria In the Netherlands, the advised limit of the endotoxin level during an average 8-hour working day is 90 endotoxin units per m3 (EU m-3) (≈ ng m-3) (The Health Council of the Netherlands, 2010) In Dutch poultry houses it has been found that the exposure levels are on average 10 to 20 times higher (Spaan et al., 2006) Wathes et al (1997) measured LPS concentrations inside broiler and layer facilities in the UK and found that these varied between winter and summer, but were always much higher (by amounts ranging from 100 to 400 ng m-3) than the recommended threshold In a study on poultry houses, pig houses, and cattle houses Seedorf et al (1998) found that the mean inhalable endotoxin concentrations (in particles 1,000) and (not countable and/or rateable) Scale humerus and radius: (no beads), (