Ranging Behaviour of Commercial Free-Range Broiler Chickens 2: Individual Variation

Little is known about broiler chicken ranging behaviour. Previous studies have monitored ranging behaviour at flock level but whether individual ranging behaviour varies within a flock is unknown. Using Radio Frequency Identification technology, we tracked 1200 individual ROSS 308 broiler chickens across four mixed sex flocks in two seasons on one commercial farm. Ranging behaviour was tracked from first day of range access (21 days of age) until 35 days of age in winter flocks and 44 days of age in summer flocks. We identified groups of chickens that differed in frequency of range visits: chickens that never accessed the range (13 to 67% of tagged chickens), low ranging chickens (15 to 44% of tagged chickens) that accounted for

Ranging Behaviour of Commercial Free-Range Broiler Chickens 1: Factors Related to Flock Variability

Little is known about the ranging behaviour of chickens. Understanding ranging behaviour is required to improve management and shed and range design to ensure optimal ranging opportunities. Using Radio Frequency Identification technology, we tracked 300 individual broiler chickens in each of four mixed sex ROSS 308 flocks on one commercial farm across two seasons. Ranging behaviour was tracked from the first day of range access (21 days of age) until 35 days of age in winter and 44 days of age in summer. Range use was higher than previously reported from scan sampling studies. More chickens accessed the range in summer (81%) than winter (32%; p p

An attention bias test to assess anxiety states in laying hens

Fear is a response to a known threat, anxiety is a response to a perceived threat. Both of these affective states can be detrimental to animal welfare in modern housing environments. In comparison to the well-validated tests for assessing fear in laying hens, tests for measuring anxiety are less developed. Perception of a threat can result in an attention bias that may indicate anxious affective states in individual hens following playback of an alarm call. In Experiment 1, an attention bias test was applied to hens that differed in their range access to show that hens that never ranged were more vigilant (stretching of the neck and looking around: P P = 0.01) compared with hens that ranged daily. All hens showed a reduction in comb temperature following the first alarm call (P meta-Chlorophenylpiperazine (m-CPP) in adult laying hens. Hens dosed with 2 mg/kg showed reduced locomotion compared with a saline solution (P m-CPP or saline was administered to adult hens previously habituated to the open field arena to pharmacologically validate an attention bias test as a measure of anxiety. Hens dosed with m-CPP were slower to feed (P = 0.02) and faster to vocalize following a second alarm call playback (P = 0.03) but these hens did not exhibit the same vigilance behavior as documented in Experiment 1. The m-CPP hens also spent more time stepping and vocalizing (both P m-CPP resulted in motionless behavior when the environment was novel, but more movement and vocalizing when the environment was familiar. The extreme behavioral phenotypes exhibited by individually-tested birds may both be indicators of negative states

Primaquine dose and the risk of haemolysis in patients with uncomplicated Plasmodium vivax malaria: a systematic review and individual patient data meta-analysis

Background: Primaquine radical cure is used to treat dormant liver-stage parasites and prevent relapsing Plasmodium vivax malaria but is limited by concerns of haemolysis. We undertook a systematic review and individual patient data meta-analysis to investigate the haematological safety of different primaquine regimens for P vivax radical cure. Methods: For this systematic review and individual patient data meta-analysis, we searched MEDLINE, Web of Science, Embase, and Cochrane Central for prospective clinical studies of uncomplicated P vivax from endemic countries published between Jan 1, 2000, and June 8, 2023. We included studies if they had active follow-up of at least 28 days, if they included a treatment group with daily primaquine given over multiple days where primaquine was commenced within 3 days of schizontocidal treatment and was given alone or coadministered with chloroquine or one of four artemisinin-based combination therapies (ie, artemether–lumefantrine, artesunate–mefloquine, artesunate–amodiaquine, or dihydroartemisinin–piperaquine), and if they recorded haemoglobin or haematocrit concentrations on day 0. We excluded studies if they were on prevention, prophylaxis, or patients with severe malaria, or if data were extracted retrospectively from medical records outside of a planned trial. For the meta-analysis, we contacted the investigators of eligible trials to request individual patient data and we then pooled data that were made available by Aug 23, 2021. The main outcome was haemoglobin reduction of more than 25% to a concentration of less than 7 g/dL by day 14. Haemoglobin concentration changes between day 0 and days 2–3 and between day 0 and days 5–7 were assessed by mixed-effects linear regression for patients with glucose-6-phosphate dehydrogenase (G6PD) activity of (1) 30% or higher and (2) between 30% and less than 70%. The study was registered with PROSPERO, CRD42019154470 and CRD42022303680. Findings: Of 226 identified studies, 18 studies with patient-level data from 5462 patients from 15 countries were included in the analysis. A haemoglobin reduction of more than 25% to a concentration of less than 7 g/dL occurred in one (0·1%) of 1208 patients treated without primaquine, none of 893 patients treated with a low daily dose of primaquine (<0·375 mg/kg per day), five (0·3%) of 1464 patients treated with an intermediate daily dose (0·375 mg/kg per day to <0·75 mg/kg per day), and six (0·5%) of 1269 patients treated with a high daily dose (≥0·75 mg/kg per day). The covariate-adjusted mean estimated haemoglobin changes at days 2–3 were –0·6 g/dL (95% CI –0·7 to –0·5), –0·7 g/dL (–0·8 to –0·5), –0·6 g/dL (–0·7 to –0·4), and –0·5 g/dL (–0·7 to –0·4), respectively. In 51 patients with G6PD activity between 30% and less than 70%, the adjusted mean haemoglobin concentration on days 2–3 decreased as G6PD activity decreased; two patients in this group who were treated with a high daily dose of primaquine had a reduction of more than 25% to a concentration of less than 7 g/dL. 17 of 18 included studies had a low or unclear risk of bias. Interpretation: Treatment of patients with G6PD activity of 30% or higher with 0·25–0·5 mg/kg per day primaquine regimens and patients with G6PD activity of 70% or higher with 0·25–1 mg/kg per day regimens were associated with similar risks of haemolysis to those in patients treated without primaquine, supporting the safe use of primaquine radical cure at these doses. Funding: Australian National Health and Medical Research Council, Bill & Melinda Gates Foundation, and Medicines for Malaria Venture

Socializing One Health: an innovative strategy to investigate social and behavioral risks of emerging viral threats

In an effort to strengthen global capacity to prevent, detect, and control infectious diseases in animals and people, the United States Agency for International Development’s (USAID) Emerging Pandemic Threats (EPT) PREDICT project funded development of regional, national, and local One Health capacities for early disease detection, rapid response, disease control, and risk reduction. From the outset, the EPT approach was inclusive of social science research methods designed to understand the contexts and behaviors of communities living and working at human-animal-environment interfaces considered high-risk for virus emergence. Using qualitative and quantitative approaches, PREDICT behavioral research aimed to identify and assess a range of socio-cultural behaviors that could be influential in zoonotic disease emergence, amplification, and transmission. This broad approach to behavioral risk characterization enabled us to identify and characterize human activities that could be linked to the transmission dynamics of new and emerging viruses. This paper provides a discussion of implementation of a social science approach within a zoonotic surveillance framework. We conducted in-depth ethnographic interviews and focus groups to better understand the individual- and community-level knowledge, attitudes, and practices that potentially put participants at risk for zoonotic disease transmission from the animals they live and work with, across 6 interface domains. When we asked highly-exposed individuals (ie. bushmeat hunters, wildlife or guano farmers) about the risk they perceived in their occupational activities, most did not perceive it to be risky, whether because it was normalized by years (or generations) of doing such an activity, or due to lack of information about potential risks. Integrating the social sciences allows investigations of the specific human activities that are hypothesized to drive disease emergence, amplification, and transmission, in order to better substantiate behavioral disease drivers, along with the social dimensions of infection and transmission dynamics. Understanding these dynamics is critical to achieving health security--the protection from threats to health-- which requires investments in both collective and individual health security. Involving behavioral sciences into zoonotic disease surveillance allowed us to push toward fuller community integration and engagement and toward dialogue and implementation of recommendations for disease prevention and improved health security

Relationships between ranging behaviour and welfare of commercial free-range broiler chickens

© 2017 Dr. Peta Simone TaylorFree-range chicken meat consumption has increased, partly driven by consumer perception that free-range housing is better for welfare. However, there have been few scientific investigations into the implications of ranging on broiler chicken welfare. Furthermore, how and why chickens access an outdoor range is largely unknown. Previous research has monitored broiler chicken ranging and welfare at the flock level. However, not all chickens access the range when the opportunity is provided. Subsequently, measures at the flock level may not be an accurate assessment of the implications of range use. With the advancement of technology, tracking individual chicken ranging behaviour is now possible. The research presented throughout this thesis was designed to obtain a greater understanding of the relationships between individual ranging behaviour of free-range broiler chickens on commercial farms and the relationships with welfare. Chapters Three and Four provide descriptive analysis of the environmental factors associated with ranging behaviour. Tracking individual chicken ranging behaviour showed that the proportion of the flock that accessed the range was greater than previously estimated with alternate methodologies. Range use was season dependent with fewer chickens and range visits observed in winter flocks. Heterogeneous flock ranging behaviour was considerable, including chickens that only accessed the range once (8 to 12% of tracked chickens) and high frequency ranging chickens (3 to 9% of tracked chickens) that accounted for more than one third to a half of all range visits within the flock. Chapters Five and Six investigated relationships between ranging behaviour, individual chicken characteristics and welfare. Few relationships were identified in winter flocks, which may be reflective of minimal range use. In summer flocks, lower weight, better gait scores, increased plumage cover and lower physiological stress responses prior to range access were predictive of subsequent ranging behaviour. These results suggest that individual characteristics and/or early life experience may be partially responsible for heterogeneous flock ranging behaviour. Furthermore, accessing the range was related to welfare in summer flocks after range access; including reduced fear responses and improved gait scores and cardiovascular function. The study presented in Chapter Seven, investigated relationships between distance ranged from the shed and chicken welfare. Bi-directional relationships between ranging distance and body weight were observed. Frequently ranging further from the shed was associated with improved gait scores, less hock burn, and reduced acute physiological fear responses to confinement after range access was provided. Increased foot pad dermatitis was associated with increased range visits, but not ranging distance. These results suggest that ranging further from the shed had subsequent implications for welfare. This thesis provides evidence that accessing an outdoor range has bi-directional relationships with chicken welfare. Due to the nature of the research presented in this thesis causation could not be identified. However, the research contributes to the limited knowledge of free-range broiler chicken welfare. As such, the broader understanding of ranging and welfare on commercial farms obtained through this thesis provides industry relevant, hypothesis generating evidence to aid optimal ranging behaviour on commercial farms that promotes good welfare

Indoor side fidelity and outdoor ranging in commercial free-range chickens in single- or double-sided sheds

The ranging behaviour of broiler chickens kept in free-range housing systems remains poorly understood, despite access to the outdoor range being their main feature. We investigated the impact of allowing chickens to have range access on both sides vs. one side of the shed, using 24 flocks of approximately 40,000 Ross 308 chickens of mixed sex on one commercial farm across winter and summer. Sheds were identical and pseudo-randomly allocated to either double-sided (no modification) or single-sided (by keeping one side closed at all time) range access treatment. Flocks were first provided with range access from 15 to 17 and 21 to 27 days of age for summer and winter flocks, respectively. Live outdoor observations were conducted daily for the first week after first range access and every other day from the second week onwards until the day prior to depopulation (44 days of age), twice daily in each morning and evening during anticipated peaks of range use. Indoor side fidelity was also assessed by spray marking 320 chickens in total on the right- and left-hand side of the shed, one colour each side, and conducting two to four repeated counts of the colour-marked individuals in each location over the week following marking. Indoor count results showed that colour-marked chickens had 50% chance of being found on either side of the shed (

A Preliminary Study Investigating the Impact of Musical Concerts on the Behavior of Captive Fiordland Penguins (Eudyptes pachyrhynchus) and Collared Peccaries (Pecari tajacu)

Captive animal welfare is important for establishments that exhibit species for education, conservation, and research. However, captive animals are often exposed to a number of potential stressors, such as visitors and anthropogenic noise. We aimed to identify the impact of a concert series on the behaviour of Fiordland penguins (Eudyptes pachyrhynchus; n = 2), and solitary- (n = 1) or group- (n = 4)-housed collared peccaries (Pecari tajacu). Animal behaviour, visitor density, and visitor behaviour was monitored pre-concert (afternoons; 16:00–19:00), during the concert (evenings; 19:00–21:00), and post-concert (nights; 21:00–00:00) on concert days (penguin n = 7 days; peccary n = 8 days) and in the same periods on days when there was no concert (penguin n = 8 days; peccary n = 6 days). Fiordland penguins spent more time surface swimming and diving in the pool on concert afternoons and evenings (all p p p = 0.019), and engaged with their habitat less on concert evenings and nights (p = 0.002) compared to these periods on days without a concert. The group-housed peccaries slept more in the afternoon and evening (p ⋜ 0.01) and were more vigilant at night (p = 0.009) on concert days compared to no-concert days. The solitary-housed peccary slept more on concert nights (p = 0.035), rested more frequently across all time periods on concert days (p

What's in a name - the role of education and rhetoric in improving laying hen welfare

The rhetoric of laying hen welfare influences people's emotions. Terms like 'cage-free' and 'caged' connotes 'liberty' or 'imprisonment', or simply, 'good' or 'bad' for the hen. Science can determine the risk that the chicken egg industry (hereafter industry) practices pose to hen welfare, but a social license to operate will ultimately determine whether these practices are acceptable. Science and social licence do not always align and can lead to serious negative welfare consequences for hens. Furnished cages were designed as a compromise between the welfare implications of conventional cage and free-range systems, but societal concerns may still occur on the rhetoric that any cage is still a 'cage'

Anticipatory Behavior for a Mealworm Reward in Laying Hens Is Reduced by Opioid Receptor Antagonism but Not Standard Feed Intake

It is widely accepted that the absence of suffering no longer defines animal welfare and that positive affective experiences are imperative. For example, laying hens may be housed in environments that do not cause chronic stress but may lack particular resources that promote positive affective experiences, such as conspecifics or effective enrichment. Despite a consensus of how important positive affect is for animal welfare, they are difficult to identify objectively. There is a need for valid and reliable indicators of positive affect. Pharmacological interventions can be an effective method to provide insight into affective states and can assist with the investigation of novel indicators such as associated biomarkers. We aimed to validate a pharmacological intervention that blocks the subjective hedonistic phase associated with reward in laying hens via the administration of the non-selective (μ, δ, and κ) opioid receptor antagonist, nalmafene. We hypothesized that nonfood deprived, hens that did not experience a positive affective state when presented with a mealworm food reward due to the administration of nalmefene, would show minimal anticipatory and consummatory behavior when the same food reward was later presented. Hens (n = 80) were allocated to treatment groups, receiving either nalmefene or vehicle (0.9% saline) once or twice daily, for four consecutive days. An anticipatory test (AT) was performed on all days 30 min post-drug administration. Behavioral responses during the appetitive and consummatory phase were assessed on days 1, 3 and 4. Anticipatory behavior did not differ between treatment groups the first time hens were provided with mealworm food rewards. However, antagonism of opioid receptors reduced anticipatory and consummatory behavior on days 3 and 4. Feed intake of standard layer mash was not impacted by treatment, thus nalmefene reduced non-homeostatic food consumption but not homeostatic consumption. Behavioral observations during the AT provided no evidence that nalmefene treated hens were fearful, sedated or nauseous. The results suggest that we successfully blocked the hedonistic subjective component of reward in laying hens and provide evidence that this method could be used to investigate how hens perceive their environment and identify associated novel indicators to assess hen welfare