Little is known about the implications of accessing an outdoor range for broiler chicken welfare, particularly in relation to the distance ranged from the shed. Therefore, we monitored individual ranging behaviour of commercial free-range broiler chickens and identified relationships with welfare indicators. The individual ranging behaviour of 305 mixed-sex Ross 308 broiler chickens was tracked on a commercial farm from the second day of range access to slaughter age (from 16 to 42 days of age) by radio frequency identification (RFID) technology. The radio frequency identification antennas were placed at pop-holes and on the range at 2.7 and 11.2 m from the home shed to determine the total number of range visits and the distance ranged from the shed. Chickens were categorised into close-ranging (CR) or distant-ranging (DR) categories based on the frequency of visits less than or greater than 2.7 m from the home shed, respectively. Half of the tracked chickens (n=153) were weighed at 7 days of age, and from 14 days of age their body weight, foot pad dermatitis (FPD), hock burn (HB) and gait scores were assessed weekly. The remaining tracked chickens (n=152) were assessed for fear and stress responses before (12 days of age) and after range access was provided (45 days of age) by quantifying their plasma corticosterone response to capture and 12 min confinement in a transport crate followed by behavioural fear responses to a tonic immobility (TI) test. Distant-ranging chickens could be predicted based on lighter BW at 7 and 14 days of age (P=0.05), that is before range access was first provided. After range access was provided, DR chickens weighed less every week (P=0.001), had better gait scores (P=0.01) and reduced corticosterone response to handling and confinement (P<0.05) compared to CR chickens. Longer and more frequent range visits were correlated with the number of visits further from the shed (P<0.01); hence distant ranging was correlated with the amount of range access, and consequently the relationships between ranging frequency, duration and distance were strong. These relationships indicate that longer, more frequent and greater ranging from the home shed was associated with improved welfare. Further research is required to identify whether these relationships between ranging behaviour and welfare are causal.

Salmonellosis, caused by Salmonella spp., is a widely reported foodborne zoonosis frequently associated with ingestion of poultry products. Salmonella vaccination of chickens can be used to reduce bacterial shedding and risk of human infection. To determine Salmonella burden in chicken farms, culture methods of environmental samples that require a turn-around time of 5-7 days are usually used. Rapid screening using molecular assays such as PCR of pre-enriched broth has been reported for Salmonella spp. detection in feed, floor dust, and drag swabs within 2-3 days. Here we report an adaptation of the method for detection of Salmonella in poultry dust samples collected using a settle plate method under experimental conditions. Key features:

• Passive dust sample collection using dry settle plates without media suspended from dropper lines of drinkers.
• Small amount of sample required for the pre-enrichment process.
• Quantification of Salmonella DNA with high sensitivity using an inexpensive extraction protocol.

Context. Drinking water vaccination of young meat chickens with Infectious Laryngotracheitis (ILT) vaccine is problematic. Vaccine failure and adverse vaccine reactions are frequently reported. Variations in the technique of applying ILT vaccines by this mass vaccination method need to be understood to contribute to improving the success of vaccination.

Aims. This study aimed to examine variations in the techniques of application of Infectious Laryngotracheitis vaccines via drinking water for young meat chickens.

Methods. Drinking water vaccination techniques were observed and recorded across 52 broiler flocks during ILT outbreaks in three geographic areas of Australia. Descriptive statistics for all variables were computed and variations between integrator company procedures were statistically compared.

Key results. Despite rigorous standard operating procedures, wide variations were observed in time of water deprivation prior to vaccination (3–15 min), time drinking water was stabilised prior to addition of vaccine and the type of stabiliser product used, time to activate the flock following filling of the water lines with vaccine (10–127 min), time for the vaccine to be consumed (36–226 min) and the volume of drinking water per bird used to provide the vaccine (11–48 mL/bird).

Conclusions. Variation in vaccination technique can affect the success of drinking water vaccination against ILT in young meat chickens.

Implications. Understanding the importance of the variable factors in vaccine application method can improve the success of water vaccination against ILT.

In Ethiopia, most chicken disease outbreaks and mortalities are attributed to a respiratory syndrome known as “fengil” with variable clinical signs and undefined etiology. The main goal of this study was to determine whether key respiratory pathogens that could contribute to the fengil syndrome circulate in Ethiopia. Specifically, we aimed to determine the seroprevalence of infectious laryngotracheitis virus (ILTV), infectious bronchitis virus (IBV), Newcastle disease virus (NDV), Mycoplasma gallisepticum (Mg), and avian metapneumovirus (aMPV). A cross-sectional survey was conducted in 158 scavenging and 42 small and medium-scale intensive chicken holdings in the East, West and North Shewa Zones of central Ethiopia. Blood from 495 chickens was collected and serological tests were used to determine exposure to these pathogens. Vaccination against NDV was the only immunization practiced with a significantly higher vaccination rate in the intensive than the scavenging system. Serological evidence of a high level of exposure to all pathogens was detected, including the first report on the seroprevalence of aMPV, ILTV, and IBV in the East Shewa Zone. The chicken and holding seroprevalence rates were respectively 91% and 94% for IBV, 34% and 57% for aMPV, 47% and 66% for Mg, 27% and 51% for ILTV and in unvaccinated flocks, 39% and 53% for NDV. These pathogens could contribute to the fengil syndrome, commonly ascribed to NDV. The seroprevalence of aMPV and ILTV was higher in chickens under the scavenging system. Exposure to multiple pathogens was common, with more than 50% of chickens positive for three or more pathogens in the scavenging system. This was reflected in significant positive associations between seropositivity to ILTV, Mg, ILTV, and IBV. The role of these pathogens in the causation of respiratory disease in the field requires further investigation.