Now showing 1 - 10 of 22
  • Publication
    Anticipatory Behavior for a Mealworm Reward in Laying Hens Is Reduced by Opioid Receptor Antagonism but Not Standard Feed Intake
    (Frontiers Research Foundation, 2020-01-14) ; ;
    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.
  • Publication
    Frequent range visits further from the shed relate positively to free-range broiler chicken welfare
    (Elsevier BV, 2020) ;
    Hemsworth, P H
    ;
    ;
    Gebhardt-Henrich, S G
    ;
    Rault, J-L

    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.

  • Publication
    Effect of woodchip bedding during wet conditions on feedlot cattle productivity, behaviour and relative adrenal gland weight

    Problems associated with muddy pens have been identified as some of the most serious animal welfare issues related to outdoor feedlot beef production, but there is relatively little work examining the use of woodchip bedding for lot-fed beef cattle under conditions of cold, wet, but non-freezing winters on soil under-bases. This study examined the effects of graded levels of woodchip on the performance and behaviour of feedlot cattle housed in wet pen conditions. Bos taurus steers (n = 300" 379.1 ± 24.1 kg) were blocked by weight and breed and randomly assigned to 30 10-steer feedlot pens provided with either no woodchip bedding (Control, n = 10) manure interface only, or 15 cm depth of woodchip bedding (W15, n = 10) or 30 cm depth of woodchip bedding (W30, n = 10). The steers were housed in these treatment pens for 109 days on a feedlot ration, and the pens were irrigated so that approximately 74 mm of total precipitation (irrigation + natural rainfall) fell onto the pen surface every 30 days. Temperatures were mostly <20 C maximum and 1 to 5 C minimum. Steers were weighed on five occasions. Animal position and posture in pen were recorded once a week over an 8-hour day-time period. Carcase characteristics were measured, and adrenal gland weights were recorded. Providing woodchip bedding increased liveweight gain (P < 0.001) and gain:feed (G:F, P = 0.012) after day 28, increased DM intake (DMI) after day 92 (P = 0.049), and increased carcase weight (P = 0.001) and dressing percentage (P = 0.023). There was no additional benefit of W30 over W15 for liveweight gain or DMI, but the benefit of W15 for G:F was lower than that of W30 by the end of the feeding period (P = 0.012). There were no effects of bedding on other carcase quality traits. Steers in Control pens utilised the front of the pen for lying and standing more than the W15 and W30 steers (P < 0.001) suggesting the steers in the Control pens perceived the front of the pen as less aversive, potentially due to increased drainage compared to rest of the pen and proximity to feed bunk. Adrenal gland weight/kg and carcase weight tended to be higher in the Control treatment group than the W30 steers (P = 0.077). This research has demonstrated that for a 109-day feeding period in cold, wet conditions, steer performance and welfare can be improved by providing a minimum of 15 cm woodchip bedding.

  • Publication
    A Preliminary Study Investigating the Impact of Musical Concerts on the Behavior of Captive Fiordland Penguins (Eudyptes pachyrhynchus) and Collared Peccaries (Pecari tajacu)
    (MDPI AG, 2020-11-04)
    Fanning, Lara
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    Larsen, Hannah
    ;
    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 < 0.001), more time in the nest on concert nights (p < 0.001), preened less on concert afternoons and nights (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 < 0.001), and used the front of the enclosure more across all concert time periods (p < 0.001) compared to no-concert days. We provide evidence that behaviour was altered on event days; however, we cannot determine the nature of these changes. Further research is needed to understand the impact of music concerts on zoo animal welfare.
  • Publication
    Effect of pecking stones and age on feather cover, hen mortality, and performance in free-range laying hens
    (Elsevier BV, 2020-05) ; ; ; ;
    Perez-Maldonado, Rider Anderson
    ;
    Severe feather pecking is frequently associated with impaired egg production, poor hen welfare, and increased mortality. The aim of this study was to investigate the potential of pecking stones to ameliorate the incidence of feather pecking. A total of 18 flocks of Hy-Line Brown laying hens were randomly assigned to control (n = 9 no pecking stone access) or treatment (n = 9 pecking stone access) flocks and housed in commercial fixed sheds (farm A, n = 10) or commercial mobile sheds (farm B, n = 8) differing in various housing conditions. Beak length, feather score, egg production, and mortality were evaluated at 16 wk of age and every 10 wk until at least 46 wk of age. On farm A, hens with access to pecking stones had significantly lower mortality than hens without pecking stone access (P = 0.001). A significant interaction between pecking stone and age was observed on feather scores of wings of hens housed in farm A. Hens of the pecking stone group in farm A had higher wing feather score (indicating better feather condition) at the age of 56 and 66 wk than hens with no access to pecking stones (pecking stone × age, P = 0.002). The age of the hens was significantly associated with lower overall feather scores (poorer feather condition), reduced egg production, and higher mortality (P,0.05). Although pecking stones reduced some feather loss and mortality, this effect was only present on one farm and therefore may be related to farm management. Especially the impact of pecking stones on mortality was inconclusive as the cumulative mortality in farm B was nearly twice as high compared with that in control flocks. Further investigations are warranted including the effects of pecking stone provision at an early age such as during rearing (0–17 wk of age).
  • Publication
    The role of education and attitudes towards hen welfare: a case study of furnished cages
    (Poultry Hub Australia, 2020-06-20) ; ;
    Hemsworth, Lauren

    The aim of this research was to develop an understanding of the Australian community's knowledge and perception of hen welfare and furnished cages and to determine the impact of and effectiveness education campaigns in relation to language. Additionally, this research attempted to understand the potential barriers of communication between industry and the Australian community in matters of hen welfare and housing systems. We hypothesised that the community's knowledge of poultry housing and welfare would be low, there would be little awareness of furnished cages and that effectiveness of education campaigns and positive perceptions of furnished cage systems would be related to education and language.

    Knowledge of hen welfare, management practices and the Australian egg industry was low, suggesting that appropriate education campaigns are likely to improve the dialogue between the Australian community and egg industry. Education treatment groups increased knowledge of hen welfare, management and practices. Language did not impact the level of knowledge scores post treatment. Respondents predominately supported furnished cage housing systems for egg laying hens, but education campaigns were required. There was little evidence to support concerns that the 'a cage is a cage' rhetoric negatively impacts support for furnished cage support in Australia (Weary, Ventura et al. 2016). Therefore, industry may consider investing in RD&E to optimise the furnished cage design for Australian conditions to safeguard hen welfare, worker health and safety, and economics to ensure the industry is ready for transition to such an alternate housing system should the market require.

    A lack of industry participation in the current study prevented insight into the similarities and disparities in values, language and belief between community and industry stakeholders. This understanding is critical to ensure future dialogue and consultation processes are respectful and productive. Further efforts to increase industry engagement is required to obtain an understanding of the similarities' and differences in language, values and perceptions of hen welfare between industry and the community. We provide some evidence that discussions industry and community stakeholders may be using terminology that is interpreted through differences in experiences, knowledge and values. However, the validity of these findings are questionable because of the low sample size of industry participants. The current industry survey could be altered to focus on differences in language and values regarding hen welfare to provide a greater understanding.

    Although these data suggest belief can be overcome by education tools, further research is required to determine the specific factors that resulted in an effective education campaign, for example the scientific approach, industry-independent education or short engaging animations. However, there are clear benefits and opportunities for education campaigns that can improve the understanding and support for the Australian egg industry and hen welfare.

  • Publication
    Operant learning is disrupted when opioid reward pathways are blocked in the domesticated hen
    (Elsevier BV, 2020-11) ;
    Hazel, Susan J
    ;
    Ryan, Terry
    ;

    There is limited research into mesolimbic function specific to birds and, specifically, how neurobiological reward mechanisms affect learning in domestic laying hens (Gallus gallus domesticus). A more thorough understanding of these mechanisms has implications for the improvement of welfare. Reward is proposed to involve two separate processes of 'wanting' regulated by dopamine and 'liking' regulated by opioids. This study examined the effect the opioid antagonist, nalmefene, on learning in domesticated hens.

    Eighteen Isa Brown hens were randomly assigned into either a saline or nalmefene treatment group. Hens in the saline group (N = 9) received 0.9 % saline (0.5 mL/kg pectoral muscle injection). Hens in the nalmefene treatment group (N = 9) were administered an opioid antagonist (0.4 mg/kg nalmefene in 0.9 % saline pectoral muscle injection) to disrupt the reward pathway. Prior to administration of treatments, hens were habituated to the training table, cup and trainer. Training occurred over three consecutive days on a series of three tasks using operant conditioning. Hens were dosed with either saline or nalmefene thirty minutes prior training. Hens were trained for one five minute session each day. Learning tasks included (1) pecking a target, (2) colour stimulus discrimination, and (3) pecking a target on cue presentation. All tasks were trained by the same trainer who was blind to treatment, using clicker training to shape responses. By the final day of training (Day 3), more saline hens had completed Task 1 and Task 2 than hens that received nalmefene (P < 0.0001). No hens in the nalmefene treatment group completed any training task. This study demonstrates that hens treated with an opioid antagonist failed to learn any tasks during operant training sessions, using a food reinforcer, over three days. We show that hens did not learn when the ability to experience reward is blocked, providing evidence that performing operant tasks is rewarding to hens.

  • Publication
    An effective environmental enrichment framework for the continual improvement of production animal welfare
    (Cambridge University Press, 2023-02-14) ;
    Schrobback, Peggy
    ;
    Verdon, Megan
    ;

    Substrates and objects are provided to farm animals on the assumption that they improve animal welfare by enriching the environment, but these often fail to consider the extent to which an environmental enrichment (EE) improves animal welfare, if at all. Furthermore, there are numerous definitions of EE, each with a unique expectation. If expectations of animal welfare improvement are set too high, industry uptake may be thwarted, but if thresholds are set too low it will not result in meaningful improvements to animal welfare. We propose an EE framework based on revised definitions of EE that reflect improvements to various components of animal welfare: (i) pseudo-enrichment" (ii) EE for meeting basic needs" (iii) EE for pleasure" and (iv) EE for positive welfare balance. This framework requires short- and long-term assessments to determine the impact of the EE, although many are lacking in the production animal literature. Redefining EE with a focus on specific animal welfare outcomes will assist producers in identifying the optimal EE for their enterprise. Subsequently, we encourage dialogue between farmers, researchers and industry stakeholders when designing environmental enrichment programmes. This framework is a science-based tool that can be used to inform the development of clear EE assessment protocols and requirements for animal welfare legislation, assurance programmes and industry. This evidence-based framework ensures that the focus is on the outcome of EE programmes rather than the intent. Importantly, this framework has the flexibility to adapt even as baseline environments evolve, ensuring the continual improvement to production animal welfare.

  • Publication
    Visual access to an outdoor range early in life, but not environmental complexity, increases meat chicken ranging behavior
    (Elsevier BV, 2023) ;
    Fanning, L
    ;
    ; ;
    Dekoning, C
    ;
    McCarthy, C
    ;
    Rault, J L

    Not all chickens access an outdoor range when the opportunity is provided. This may be related to the abrupt change in environments from the stable rearing conditions to the complexity of the outdoor range. We aimed to prepare chickens to range by increasing the complexity of the indoor environment early in life with the intention to encourage range use. Mixed sex Cobb500 chickens were allocated to 1 of 3 treatment groups: visual access (VA) treatment provided VA to the outdoor range from day old via transparent pop-hole covers" environmental complexity (EC) treatment provided an artificial haybale, fan with streamers and a solid vertical barrier" Control treatment was a representative conventional environment. Chickens were given access to the outdoor range at 21 d of age. Behavior in the home pen was assessed in wk 1, 2 and 5 and individual ranging behavior was monitored through radio frequency identification (RFID) technology. The VA chickens were more active compared to EC (P = 0.006) and Control (P = 0.007) chickens and spent more time foraging than control chickens (P = 0.036) during the first week of life. More VA chickens accessed the range area compared to EC chickens (P = 0.015). VA chickens accessed the range sooner after they were first provided access and spent more time on the range than EC and control chickens (P < 0.001). Mortality was lower in the VA treatment compared to EC (P = 0.024) and control group (P = 0.002). There was evidence that VA chickens weighed less than Control and EC chickens, however results were inconsistent between age and sex. Hence, providing meat chickens with VA to an outdoor range early in life increased activity in early life, decreased latency to first access the range and increased time on the range and lowered mortality. Future work should aim to understand the mechanism behind these changes in behavior to develop recommendations for producers to implement in commercial conditions.

  • Publication
    Research note: Expert opinions of feather sucking and licking behavior in meat chicken breeder birds
    (Elsevier BV, 2024-06) ;
    Hemsworth, P H
    ;
    ;
    DeKoning, C

    Feather sucking, or feather licking, has been reported anecdotally by employees in the Australian meat chicken breeder industry, but scarcely in the scientific literature. Consequently, the causes and implications of this behavior in meat chicken breeding chickens is relatively unknown. We surveyed 17 industry experts to generate hypotheses about feather sucking behavior. We aimed to understand the frequency and when it occurs, and attempted to understand what may cause an "outbreak". The recruitment of participants was intentionally biased towards Australian perspectives" only 5 of the 17 participants were international. All participants, except 1, had seen feather sucking/licking behavior (94.1%) and most participants (80%) suggested that the behavior was most frequently observed during rearing. Participants presented varying concerns about this behavior, ranging from the perspective that it was "normal" and had no impact on welfare, to concerns about mating injuries due to damaged feathers, increased risk of feather pecking and cannibalism, and psychological stress indicated by expression of repetitive (seemingly) functionless behavior. "Feather licking," "feather sucking," "feather eating," and "feather pecking" were terms used interchangeably, leading to confusion by participants about the cause and implications of the target behavior. The most common factors reported as the cause were boredom (52.9%), nutritional deficiencies (47.1%), and feed restriction (41.2%) and more than 80% of respondents agreed that stress contributes to feather sucking. The outputs from this study reflect only a small, but expert, number of opinions on feather sucking/licking behaviors in the Australian meat chicken breeder industry. A systematic understanding of this behavior is needed to provide insight into causation and the implications for welfare.