Browsing by Browse by SEO 2020 "100408 Minor livestock (e.g. alpacas, ostriches, crocodiles, farmed rabbits)"

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Journal Article
Alpaca Field Behaviour When Cohabitating with Lambing Ewes
(MDPI AG, 2020)
Matthews, Paige T
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Barwick, Jamie
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Doughty, Amanda K
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Doyle, Emma K
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Morton, Christine L
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Brown, Wendy Y
A common strategy to reduce predator attack on livestock is the deployment of guardian alpacas. However, little research has been conducted on the behaviour of this species while housed with other livestock. This study monitored two male alpacas cohabitating with 180 lambing ewes in order to quantify field behaviour in two phases. Phase one assessed diurnal patterns of alpacas and lambing ewes using Global Navigation Satellite System (GNSS) collars recording data over 41 days, in combination with observational recordings. Phase two developed an alpaca behavioural ethogram through continuous observations from 05:30 to 19:30 h over a 3-day period. The two alpacas shared similar behaviours with commonality of distance travelled, and both species exhibited an increase in activity level based on speed between the times of 05:00 and 17:00 h. The GNSS data indicated that the alpacas flocked with the ewes at night sharing the same resting location, however, would spend time during the day on the outskirts of the paddock. Alpacas were observed to spend the majority of the observation period in two behavioural states: grazing (57%) and resting (27%). As a result of this study we were able to catalogue a range and frequency of field behaviours which alpacas exhibit while cohabitating with lambing ewes. However, further research is needed to determine in more detail how these behaviours correspond with the effectiveness of this species as a livestock guardian.
1083 171
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Journal Article
Application of open field, tonic immobility, and attention bias tests to hens with different ranging patterns
(PeerJ, Ltd, 2019-11-25)
Campbell, Dana L M
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Dickson, Emily J
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Lee, Caroline
Assessment of negative affective states is a key component of animal welfare research. In laying hens, excessive fearfulness results in reduced production and increased sensitivity to stress. Fearfulness can be defined as a response to a known threat, but anxiety is a response to an unknown threat and may have similar negative consequences. The open field test and tonic immobility test are commonly applied to measure fearfulness in laying hens. An attention bias test that measured individual hen's responses to playback of a conspecific alarm call in the presence of food was recently pharmacologically validated using an anxiogenic drug but was confounded by the hen's typical motionless response in a novel environment. The current study used 56-week old free-range layers to further assess the validity of an attention bias test to differentiate ranging treatment groups in comparison with the open field and tonic immobility tests. The selected hens varied in their range use patterns as tracked by radio-frequency identification technology. 'Indoor' hens did not access the range and 'outdoor' hens ranged daily; previous research has confirmed higher fearfulness in hens that remain indoors. The tonic immobility test did not differentiate ranging groups (P = 0.34), but indoor birds were slower to first step (P = 0.03) and stepped less (P = 0.02) in the open field test. The attention bias test occurred in an isolated wooden box using a conspecific alarm call playback (a threat) and mixed grain (a positive stimulus). The behavioural response of latency to resume eating following playback of the alarm call was measured to differentiate the anxiety states of the indoor and outdoor ranging birds. Before the attention bias test could occur, birds had to be habituated to the test box across three separate 5-minute sessions to increase the willingness to feed within the novel test environment. All birds ate faster across time (P < 0.001) but the indoor birds were slower to eat than the outdoor birds (P < 0.001). In this study, the latency to resume eating following an alarm call was determined to be a poor measure for highly anxious birds as they failed to eat at all. Forty-six percent of indoor hens were excluded for not eating across the 5-minute test. Of the birds that did eat, only 7% of indoor hens ate following playback of the alarm call, compared with 36% of outdoor hens. This repetition of an attention bias test for laying hens highlights the challenges in assessing hens with extreme fearful/anxious responses and that information may be missed when non-performing hens are excluded from behavioural tests. We suggest that latency to eat in a novel arena without any alarm call playback is an informative measure of anxious state that can be applied to all hens but consideration must be made of potential differences in food motivation.
1180 141
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Journal Article
An attention bias test to assess anxiety states in laying hens
(PeerJ, Ltd, 2019-07-10)
Campbell, Dana L M
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Taylor, Peta S
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Hernandez, Carlos E
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Stewart, Mairi
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Belson, Sue
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Lee, Caroline
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 < 0.001) and slower to feed following the second alarm call playback (P = 0.01) compared with hens that ranged daily. All hens showed a reduction in comb temperature following the first alarm call (P < 0.001). In Experiment 2, an open field test was used to determine an effective dose of 2 mg/kg for the anxiogenic drug meta-Chlorophenylpiperazine (m-CPP) in adult laying hens. Hens dosed with 2 mg/kg showed reduced locomotion compared with a saline solution (P < 0.05). In Experiment 3, 2 mg/kg 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 < 0.001) than the saline hens. An attention bias test could be used to assess anxiety. However, behavioral responses of hens may vary depending on their age or test environment familiarity, thus further refinement of the test is required. In these tests, 2 mg/kg of 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.
1112 150
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Journal Article
Early rearing enrichments influenced nest use and egg quality in free-range laying hens
(Cambridge University Press, 2020)
Bari, M S
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Cohen-Barnhouse, A M
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Campbell, D L M
In Australia, free-range egg production pullets are typically reared indoors, but adult layers get outdoor access. This new environment may be challenging to adapt to, which could impair egg production and/or egg quality. Adaptation might be enhanced through rearing enrichments. We reared 1386 Hy-Line Brown® chicks indoors with three treatments across 16 weeks: (1) a control group with standard litter housing conditions, (2) a novelty group providing novel objects that changed weekly, and (3) a structural enrichment group with custom-designed structures to partially impair visibility across the pen and allow for vertical movement. Pullets were transferred to a free-range system at 16 weeks of age with daily outdoor access provided from 25 until 64 weeks. Daily egg production at different laying locations (large nests, small nests and floor), weekly egg weights and egg abnormalities were recorded from 18 to 64 weeks old. External and internal egg quality parameters of egg weight, shell reflectivity, albumen height, haugh unit, yolk colour score, shell weight and shell thickness were measured at 44, 52, 60 and 64 weeks. There was a significant interaction between rearing treatment and nest box use on hen-day production from weeks 18 to 25 (P < 0.0001) with the novelty hens laying the most eggs and the control hens the fewest eggs in the nest box. Similarly, from 26 to 64 weeks, the novelty hens laid more eggs in the large nest boxes and fewer eggs on the floor than both the structural and control hens (P < 0.0001). Egg weight and abnormalities increased with age (P < 0.0001), but rearing treatment had no effect on either measure (both P ≥ 0.19). Rearing treatment affected shell reflectivity and yolk colour with the control hens showing paler colours across time relative to the changes observed in the eggs from enriched hens. The novelty hens may have established nest box laying patterns as they were more accustomed to exploring new environments. The differences in egg quality could be related to stress adaptability or ranging behaviour. This study shows that enriching environments during rearing can have some impacts on production parameters in free-range hens.
1042 3
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Journal Article
The effects of antibiotic-free supplementation on the ruminal pH variability and methane emissions of beef cattle under the challenge of subacute ruminal acidosis (SARA)
(Elsevier Ltd, 2023-07)
Simanungkalit, Gamaliel
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Bhuiyan, Momenuzzaman
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Bell, Robert
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Sweeting, Ashley
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Morton, Christine L
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Cowley, Frances
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Hegarty, Roger
Subacute ruminal acidosis (SARA) in feedlot cattle during the feed transition to grain-based diets is a significant constraint to animal health and productivity. This experiment assessed an antibiotic-free supplement (ProTect®) effects on ruminal pH variability and methane (CH₄) emissions of cattle during the challenge of SARA. Ten 18-month-old Angus steers (472 ± 4.8 kg) were randomly allocated into monensin (n = 5) and ProTect® groups (n = 5) and progressively introduced to grain diets incorporating monensin or ProTect® for 36 days of the experiment [starter (7 days; 45% grain), T1 (7 days; 56% grain), T2 (7 days; 67% grain), finisher (15 days; 78% grain)]. The pH variability on the finisher period was reduced by the ProTect® supplement (6.6% vs. 5.2%; P < 0.01), with CH₄ emissions being significantly higher relative to the monensin group [88.2 g/day (9.3 g CH₄/kg DMI) vs. 133.7 g/day (14.1 g CH₄/kg DMI); P < 0.01]. There was no difference between treatments in the time spent on the ruminal pH < 5.6 or < 5.8 (P > 0.05). The model evaluation for the ruminal pH variation indicated that the mean absolute error (MAE) proportion for both groups was good within the same range [4.05% (monensin) vs. 4.25% (ProTect®)] with identical root mean square prediction error (RMSPE) (0.34). It is concluded that the ProTect® supplement is an effective alternative to monensin for preventing SARA in feedlot cattle by managing ruminal pH variation during the transition to high-grain diets. Both monensin and ProTect® supplemented cattle exhibited lower CH₄ yield compared to cattle fed forages and low-concentrate diets.
342 2
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Journal Article
Effects of outdoor ranging on external and internal health parameters for hens from different rearing enrichments
(PeerJ, Ltd, 2020)
Bari, Md Saiful
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Laurenson, Yan C S M
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Cohen-Barnhouse, Andrew M
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Walkden-Brown, Stephen W
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Campbell, Dana L M
In Australia, free-range layer pullets are typically reared indoors, but adult layers go outdoors, and this mismatch might reduce adaptation in laying environments. Enrichments during rearing may optimise pullet development and subsequent welfare as adult free-range hens. In the outdoor environment, hens may have greater opportunities for exercise and natural behaviours which might contribute to improved health and welfare. However, the outdoor environment may also result in potential exposure to parasites and pathogens. Individual variation in range use may thus dictate individual health and welfare. This study was conducted to evaluate whether adult hens varied in their external and internal health due to rearing enrichments and following variation in range use. A total of 1386 Hy-Line Brown® chicks were reared indoors across 16 weeks with three enrichment treatments including a control group with standard housing conditions, a novelty group providing novel objects that changed weekly, and a structural group with custom-designed structures to increase spatial navigation and perching. At 16 weeks of age the pullets were moved to a free-range system and housed in nine identical pens within their rearing treatments. All hens were leg-banded with microchips and daily ranging was assessed from 25 to 64 weeks via radio-frequency identification technology. At 64–65 weeks of age, 307 hens were selected based on their range use patterns across 54 days up to 64 weeks: indoor (no ranging), low outdoor (1.4 h or less daily), and high outdoor (5.2–9 h daily). The external and internal health and welfare parameters were evaluated via external assessment of body weight, plumage, toenails, pecking wounds, illness, and post-mortem assessment of internal organs and keel bones including whole-body CT scanning for body composition. The control hens had the lowest feather coverage (p < 0.0001) and a higher number of comb wounds (P = 0.03) than the novelty hens. The high outdoor rangers had fewer comb wounds than the indoor hens (P = 0.04), the shortest toenails (p < 0.0001) and the most feather coverage (p < 0.0001), but lower body weight (p < 0.0001) than the indoor hens. High outdoor ranging decreased both body fat and muscle (both p < 0.0001). The novelty group had lower spleen weights than the control hens (P = 0.01) but neither group differed from the structural hens. The high outdoor hens showed the highest spleen (P = 0.01) and empty gizzard weights (P = 0.04). Both the rearing enrichments and ranging had no effect on keel bone damage (all P ≥ 0.19). There were no significant interactions between rearing treatments and ranging patterns for any of the health and welfare parameters measured in this study (P ≥ 0.07). Overall, rearing enrichments had some effects on hen health and welfare at the later stages of the production cycle but subsequent range use patterns had the greatest impact.
1192 204
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Thesis Doctoral
Evaluation of Feed Quality and Supply to the Small-to-Medium-Scale Poultry Sector in Tanzania
(University of New England, 2019-10-15)
Chang'a, Edwin peter
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Iji, Paul
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Gibson, John
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Said Mbaga
Poultry performance is largely dependent on feed quality and supply. This thesis incorporated four studies, two based on survey instruments and two on feeding trials, conducted to evaluate feed quality and supply to the small-to-medium (SM) scale poultry sector in Tanzania. Trial interventions to improve the feed quality using Tanzanian replica diets were undertaken. A comprehensive literature review examined the role of poultry in Tanzanian society, the poultry production systems, broiler chicken nutritional requirements, common ingredients for commercial poultry feeds, common antinutritional factors affecting feed utilization and nutrient availability, and methods of improving feed quality and supply (Chapter 2).

The findings of the survey carried out among SM-scale broiler farmers in Tanzania presented in Chapter 3 revealed the low production performance level of broiler chickens, attributable to poor feed quality and supply, high feed costs, the low market price of birds, and diseases. Chickens are sold at between five and six weeks, weighing about 1.6 kg, with an average profit margin of TZS 1 100.00 per bird. The analysis of the nutritive values of Tanzania-type chicken diets indicates that most of the diets from a variety of feed millers were low in crude protein, metabolizable energy (ME), and amino acids (Chapter 4). Eight diets were formulated at UNE, Australia, based on ingredients which are commonly used in Tanzania. The diets were formulated in pellet and mash forms, with or without microbial enzymes (Axtra XB and Quantum Blue), supplemented singly or in combination (Chapters 5 and 6). It was found that pelleted diets increased feed intake (FI) and body weight gain (BWG), and reduced feed conversion ratio (FCR). The addition of microbial enzymes, particularly in a combination of Axtra XB and Quantum Blue (phytase-containing product) also improved FI, BWG and FCR. The breasts, thighs, and drumsticks were heavier in birds fed the pelleted diets and were further improved with enzyme supplementation. Birds fed mash diets had heavier gizzard plus proventriculus, pancreas, and small intestine.

Pelleted diets also increased the apparent metabolizable energy (AME), metabolizable energy intake (MEI), net energy of production (NEp), energy retained as protein (RE_p), and efficiency of ME use for energy and protein retention, while enzymes only improved the AME and RE_p (Chapter 6). Both pelleted diets and microbial enzyme supplementation increased the digestibility of gross energy, starch, protein, and fat. The digestibility of amino acids was higher in birds fed pellets, as well as with enzyme supplementation. In addition, the digestibility of minerals (Ca, P, K, S, Zn, and Fe) was higher in birds fed pelleted diets. The microbial enzyme, Quantum Blue (QB) increased the digestibility of P, K, and Zn while Ca and P digestibility was highest when a combination of Axtra XB+QB was added to diets. The ash content, weight, length, width, and breaking strength of the tibia bones were highest in birds fed pelleted diets. The microbial enzymes improved most bone traits, with the best results observed when a combination of QB and Axtra XB was added (Chapter 6).

Cassava was evaluated as a substitute for maize in broiler diets (Chapter 7). Cassava meal was substituted for maize in four different proportions; namely, no cassava, low (25 %), medium (50 %) and high (75 %), supplemented with a cocktail of exogenous enzyme products, Rhonozyme (A and VP). High levels of cassava reduced BWG and increased FCR, which improved with the inclusion of enzymes. The dressing percentage (DP) and relative weight of drumsticks were reduced as the cassava level increased. Enzyme supplementation increased the DP, as well as absolute and relative breast, thigh and drumstick weight. The tibia ash content, weight, length, width, and bone strength decreased with higher levels of cassava but increased with the addition of the enzymes. The Ca, K, and Zn content of bones increased with higher levels of cassava, while P and Mg decreased. All mineral contents in the tibia bones improved with enzymes. Body fat and energy retained as fat (RE_f) decreased as the cassava level increased, while body protein and RE_p were unaffected by the cassava level. The inclusion of enzymes increased the body protein content and RE_p with a slight increase in body fat. In general, broiler performance was depressed by higher levels of cassava in the diets but was improved with microbial enzyme supplementation.

The principal findings of this thesis confirm that the overall low performance of broiler chickens in Tanzania is linked to poor quality feeds and the high cost of ingredients. Most commercial feeds from Tanzanian producers exhibited low levels of the major nutrients and there was great variation in the feeds from different mills. Feed form also influenced the performance of broilers, with birds fed pelleted diets exhibiting superior performance to those on mash diets. Cassava meal can replace up to 50 % maize in broiler diets with no deleterious effects to bird performance. The application of the interventions tested in this study could benefit the Tanzanian poultry sector.
391 2
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Open Access
Journal Article
Free-range egg production: its implications for hen welfare
(CSIRO Publishing, 2021)
Campbell, D L M
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Bari, M S
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Rault, J-L
Free-range laying hen housing systems are prevalent in Australia and perceived by consumers to provide greater opportunities for the expression of natural behaviour resulting in higher hen welfare. However, all housing systems have both benefits and risks and scientific evidence is needed on the welfare outcomes of free-range systems. In this review, the scientific literature is summarised from the past 10 years, from research conducted within Australia or internationally with brown laying-hen strains kept in free-range systems. It compiles information on range use by laying hens, hen behaviour while on the range, factors that affect range use, and impacts of ranging on hen health and other aspects of welfare. Novel insights have come from the use of radio-frequency identification systems that allow tracking of individual hens and have shown that the majority of hens access the range with multiple visits across the day, but a small proportion of hens within most flocks choose to remain indoors. Hens also vary in which areas of the range they use, and provision of natural or man-made shelters can increase both range access and range distribution. Hens spend most of their time foraging while outdoors, but the types and frequencies of behaviours vary depending on the resources available and other factors. Range access can be linked to health benefits such as improved plumage condition and reduced footpad dermatitis but there are also health risks associated with free-range systems such as greater susceptibility to disease (e.g. spotty liver disease), heat stress, predation, and potentially parasites in comparison to loose or cage housing systems. Design of the range area, indoor shed, management practices and rearing environments can all influence how hens utilise free-range housing systems. Further research is crucially needed on the impact of ranging on hen welfare in variable Australian climatic conditions, encompassing intense heat and sunlight as well as cooler or wet environments.
1144 6
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Journal Article
Identification of a novel microRNA important for melanogenesis in alpaca ('Vicugna pacos')
(American Society of Animal Science, 2015)
Yang, S
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Fan, R
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Dong, C
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Shi, Z
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Ji, K
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Zhang, J
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Wang, H
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Herrid, Muren
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Zhang, Q
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Yao, J
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Smith, G W
The molecular mechanisms underlying the formation of coat colors in animals are poorly understood. Recent studies have demonstrated that microRNA play important roles in the control of melanogenesis and coat color in mammals. In a previous study, we characterized the miRNA expression profiles in alpaca skin with brown and white coat color and identified a novel miRNA (named lpa-miR-nov-66) that is expressed significantly higher in white skin compared to brown skin. The present study was conducted to determine the functional roles of this novel miRNA in the regulation of melanogenesis in alpaca melanocytes. lpa-miR-nov-66 is predicted to target the soluble guanylate cyclase ('sGC') gene based on presence of a binding site in the sGC coding sequence (CDS). Overexpression of lpa-miR-nov-66 in alpaca melanocyes upregulated the expression of sGC both at the mRNA and protein level. Overexpression of lpa-miR-nov-66 in melanocyes also resulted in decreased expression of key melanogenic genes including tyrosinase ('TYR'), tyrosinase related protein 1 ('TYRP1'), and microphthalmia transcription factor ('MITF'). Our ELISA assays showed increased cyclic guanosine monophosphate (cGMP) but decreased cyclic adenosine monophosphate (cAMP) production in melanocytes overexpressing lpa-miR-nov-66. In addition, overexpression of lpa-miR-nov-66 also reduced melanin production in cultured melanocytes. Results support a role of lpa-miR-nov-66 in melanocytes by directly or indirectly targeting sGC, which regulates melanogenesis via the cAMP pathway.
1895
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Book Chapter
Poultry welfare monitoring: wearable technologies
(Burleigh Dodds Science Publishing Limited, 2020-09-28)
Campbell, Dana L M
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Erasmus, Marisa A
This chapter reviews poultry welfare monitoring, specifically focusing on wearable technologies. It begins by discussing the use of radio-frequency identification technology (RFID) systems in chickens and other housing systems. The chapter then goes on to address wearable sensors and accelerometers, focusing on the effects of these sensors on chicken behaviour and how the different behavioural activities can be classified. It also highlights how these sensors can be used for monitoring disease and euthanasia in chickens, as well as monitoring perching, jumping, falls and collision. A section on the importance of using wearable technologies for measuring physical activity levels is also included, which is then followed by a case study that analyses outdoor stocking density in free-range laying hens. The chapter concludes by providing potential areas for future research as well as giving examples of resources for further information on the subject.
1437 4
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Journal Article
Rearing Enrichments Affected Ranging Behavior in Free-Range Laying Hens
(Frontiers Research Foundation, 2020-08-14)
Campbell, Dana L M
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Dyall, Tim R
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Downing, Jeff A
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Cohen-Barnhouse, Andrew M
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Lee, Caroline
Within Australia, free-range systems are prevalent, but pullets destined for range access are reared indoors. This mismatch between rearing and layer housing may hinder adaptation to the free-range environment. Rearing enrichments could enhance pullet development. A total of 1,386 Hy-Line Brown® chicks were reared inside an experimental facility across 16 weeks with 3 enrichment treatments including (1) a control group with standard floor-housing, (2) a novelty group providing novel objects that changed weekly ("novelty" hens), and (3) a structural group with custom-designed H-shaped structures including opaque sides ("structural" hens). At 16 weeks of age, all pullets were leg-banded with microchips and moved to an experimental free-range system with 9 identical pens (n = 3/rearing treatment). From 25 to 64 weeks, individual hen daily ranging behavior was tracked via radio-frequency identification technology and grouped into 6 age periods per rearing treatment. Video footage was used to count the number of hens at different distances on the range for the first 14 days of access, and eggs were assessed for albumen corticosterone concentrations 4 days prior to (n = 450) and 1 week after first range access (n = 450). Across most age periods, the structural hens spent the most time ranging (P ≤ 0.01), the novelty hens showed the fewest number of visits to the range (P < 0.0001), and both enriched hen groups had the longest maximum visit durations (P ≤ 0.02). Range use increased with age across all treatments with only 3% of hens never going outside. All hens were initially slow to use the range area with fewer novelty hens venturing farther onto the range (P ≤ 0.03). The structural hens had higher albumen corticosterone concentrations and variance (both P ≤ 0.004) prior to range access. All hens showed an increase in albumen corticosterone following the first week of range access resulting in no differences between rearing treatments in means (P = 0.92) and variance (P = 0.63). Different enrichments have differing impacts on ranging behavior, but further research is needed to understand the mechanisms of effects, with differences in brain lateralization a potential hypothesis to be tested.
1082 146
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Open Access
Journal Article
Relationship between Range Use and Fearfulness in Free-Range Hens from Different Rearing Enrichments
(MDPI AG, 2021-01-25)
Bari, Md Saiful
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Allen, Simon S
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Mesken, Jarrod
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Cohen-Barnhouse, Andrew M
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Campbell, Dana L M
Inconsistency between the environments of indoor pullet rearing and adult outdoor housing may increase the fearfulness in free-range hens. Rearing enrichments and/or range use may reduce adult fearfulness. Hy-Line Brown® chicks (n = 1700) were reared inside across 16 weeks with three enrichment treatments: weekly changing novel objects, custom-designed perching/navigation structures, or no additional enrichments. Pullets were transferred to a free-range system at 16 weeks of age, with range access provided from 25 weeks. At 62 weeks, 135 hens were selected from the three rearing treatments and two ranging groups (indoor: no ranging and outdoor: daily ranging) based on individual radio-frequency identification tracking. Individual behavioural tests of tonic immobility, emergence, open field, and novel object (pen level) were carried out on hens. Spectrograms of vocalisations were analysed for the open field test, as well as computer vision tracking of hen locomotion. The results showed few effects of rearing treatments, with outdoor rangers less fearful than indoor hens. The latency to step in the open field test negatively correlated with hen feather coverage. These results show that individual variation in ranging behaviours is present even following rearing enrichment treatments, and subsequent range use might be an indicator of bird fearfulness.
1152 132
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Journal Article
Relationships Between Rearing Enrichments, Range Use, and an Environmental Stressor for Free-Range Laying Hen Welfare
(Frontiers Research Foundation, 2020-08-14)
Bari, Md Saiful
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Downing, Jeff A
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Dyall, Tim R
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Lee, Caroline
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Campbell, Dana L M
Enrichments during pullet rearing may improve adaptation and welfare of hens as they move from indoor rearing to a free-range system. Individual variation in outdoor ranging may also affect welfare. This study assessed the effects of rearing enrichments and an imposed environmental stressor on hen welfare and egg quality along with the association of welfare with ranging. Hy-Line Brown® chicks (n = 1,386) were reared indoors until 16 weeks with 3 enrichment treatments including a "control" group with standard floor litter, a "novelty" group that received novel objects that were changed weekly, and a "structural" group with H-shaped perching structures. Pullets were then moved to a free-range system with three replicates of each rearing treatment. Daily ranging was individually tracked from 25 to 64 weeks via radiofrequency identification technology. Individual hen welfare assessments were performed at 25, 33, 43, 56, and 64 weeks and correlated with ranging time prior to these dates. At 44 weeks, the range area was reduced by 80% for 11 days to induce stress. Changes in ranging behavior, albumen corticosterone concentrations and egg quality were evaluated. GLMMs showed significant interactions between hen age and rearing treatment for live weight, number of comb wounds, plumage coverage, and toenail length (all P ≤ 0.003), with the enriched hens showing more consistent live weight at the later ages, fewer comb wounds at 33 weeks, and better plumage coverage at the later ages, whereas the structural hens had shorter toenails as age increased. Plumage coverage showed a positive relationship with range use across most age points (P < 0.0001). Hens reduced ranging time following the imposed stressor but increased their number of visits with the lowest increase by the structural hens (P = 0.03). Significant interactions between rearing treatment and stressor for albumen corticosterone concentrations showed the structural hens decreased concentrations immediately post-stress, but the control and novelty groups increased (P < 0.006). The stressor increased or decreased values of most egg quality parameters across all rearing groups (all P ≤ 0.02). Overall, provision of rearing enrichments and greater range use may have positive impacts on hen welfare.
1082 147
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Journal Article
A review of environmental enrichment for laying hens during rearing in relation to their behavioral and physiological development
(Elsevier BV, 2019-01-01)
Campbell, D L M
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de Haas, E N
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Lee, C
Globally, laying hen production systems are a focus of concern for animal welfare. Recently, the impacts of rearing environments have attracted attention, particularly with the trend toward more complex production systems including aviaries, furnished cages, barn, and free-range. Enriching the rearing environments with physical, sensory, and stimulatory additions can optimize the bird's development but commercial-scale research is limited. In this review, “enrichment” is defined as anything additional added to the bird's environment including structurally complex rearing systems. The impacts of enrichments on visual development, neurobehavioral development, auditory stimulation, skeletal development, immune function, behavioral development of fear and pecking, and specifically pullets destined for free-range systems are summarized and areas for future research identified. Visual enrichment and auditory stimulation may enhance neural development but specific mechanisms of impact and suitable commercial enrichments still need elucidating. Enrichments that target left/right brain hemispheres/behavioral traits may prepare birds for specific types of adult housing environments (caged, indoor, outdoor). Similarly, structural enrichments are needed to optimize skeletal development depending on the adult layer system, but specific physiological processes resulting from different types of exercise are poorly understood. Stimulating appropriate pecking behavior from hatch is critical but producers will need to adapt to different flock preferences to provide enrichments that are utilized by each rearing group. Enrichments have potential to enhance immune function through the application of mild stressors that promote adaptability, and this same principle applies to free-range pullets destined for variable outdoor environments. Complex rearing systems may have multiple benefits, including reducing fear, that improve the transition to the layer facility. Overall, there is a need to commercially validate positive impacts of cost-effective enrichments on bird behavior and physiology.
1033 109
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Book Chapter
Salvia Spp. as an Additive in Diets for Rabbits (Oryctolagus Cuniculus)
(Nova Science Publishers, Inc, 2020)
Hernandez Marquez, Veda Anaid
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Robles Jimenez, Lizbeth Esmeralda
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Dougherty, Holland
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Gonzalez Ronquillo, Manuel
Salvia spp. are a genus of herbaceous plants characterized by woody stems and lanceolate leaves grouped in spikes of bluish-purple leaves with wavy margins. The salvia species most commonly used as additives in animal diets are: Salvia lavandulifolia, Salvia officinalis and Salvia ispanica. One species of particular interest for livestock nutrition is Salvia hispanica, for which favorable results for average daily gain have been observed at dietary inclusion rates of 1-40% in species as varied as rabbits, goats, chickens, lambs, cattle, and quail. In rabbits, Salvia hispanica is added to diets with the goal of improving vascular function in hypercholesterolemic conditions. Common commercial rabbit diets can raise cholesterol levels, while Salvia hispanica increases levels of triacylglycerol and alpha linoleic acids, the latter of which are involved in improved vascular function. Addition of Salvia hispanica additionally alters fat partitioning and storage in rabbits, improving meat quality. Supplementation of diets with Salvia hispanica contributes to improved efficiency and improved economic gains for small producers, thereby improving the sustainability of rabbit production. The use of natural herbs such as Salvia spp. also allows for improved productivity in a manner perceived by consumers and regulatory agencies to be more "natural" than synthetic growth promoters. The objective of this review is therefore to demonstrate the benefits of the addition of Salvia spp. to commercial rabbit diets.
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Journal Article
Skeletal health of layers across all housing systems and future research directions for Australia
(CSIRO Publishing, 2021)
Campbell, D L M
Modern laying hens have been selected for an astounding rate of egg production, but the physiological calcium demand takes a significant toll on their skeletal health. Bones can be assessed both in vivo and ex vivo, using a combination of different structural and mechanical analysis methods. Typically, the properties of leg, wing and keel bones are measured. Conventional caged layers are restricted in movement, which imbalances structural bone resorption and new bone formation, resulting in osteoporosis. Hens within alternative housing systems have opportunities to exercise for strengthening bones, but they can also suffer from higher rates of keel fractures and/or deviations that are likely to have resulted from collisions or pressure force. Limited research has been conducted within Australian commercial housing systems to assess hen skeletal health, including prevalence of keel damage across different system types. Research conducted on both brown and white hen strains approximately within the past decade internationally (2009 onward) has shown that skeletal health is impaired across all housing systems. Keel-bone damage is of specific concern as it occurs at high rates, particularly in multi-tiered systems, is painful, can alter hen behaviour, and reduce both production and egg quality. Management strategies such as the provision of ramps to access perches and tiers can reduce the incidence of keel-bone damage to a degree. Bone strength can be improved through exercise opportunities, particularly when available during pullet rearing. Genetic selection for high bone strength may be necessary for hens to adequately adapt to loose-housed systems, but the best strategy for improving skeletal health is likely to be multifactorial.
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Journal Article
Using Radio-Frequency Identification Technology to Measure Synchronised Ranging of Free-Range Laying Hens
(MDPI AG, 2018-11-16)
Campbell, Dana L M
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Horton, Brian J
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Hinch, Geoff N
Free-range laying hen systems provide individuals a choice between indoor and outdoor areas where range use may be socially influenced. This study used radio-frequency identification technology to track the ranging of individually-tagged hens housed in six experimental free-range pens from 28 to 38 weeks of age (46–50 hens/pen). All daily visits to the range were used to study group behaviour. Results showed that 67.6% (SD = 5.0%) of all hen movements through the pop-holes outdoors or indoors were following the movement of another hen (‘pop-hole-following’) compared to only 50.5% of movements in simulated random data. The percentage overlap in time that all combinations of hen pairs within each pen spent simultaneously outdoors or indoors showed a median value of overlap greater than the 90th percentile of random data. Pens housing hens that had been provided variable enrichments from 4 to 21 days (n = 3 pens) showed higher ‘pop-hole-following’ behaviour and a higher percentage of hen-pair association compared to hens reared in non-enriched conditions (n = 3 pens). These results show that birds in each free-range pen were primarily a cohesive flock and early enrichment improved this social cohesiveness. These results have implications for understanding free-range flock-level behaviour.
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