| 1. |
- Alm, Malin, et al.
(författare)
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Corticosterone metabolites in laying hen droppings-Effects of fiber enrichment, genotype, and daily variations
- 2014
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Ingår i: Poultry Science. - : Elsevier BV. - 0032-5791 .- 1525-3171. ; 93, s. 2615-2621
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Tidskriftsartikel (refereegranskat)abstract
- There is growing interest and concern for animal welfare in commercial poultry production. To evaluate stress and welfare in an objective and noninvasive way, fecal corticosterone metabolites (FCM) in droppings can be analyzed. However, the influence of diet, genotype, and daily variations in FCM and production of droppings in laying hens has been poorly investigated. This study examined the effect of insoluble fiber by adding 3% ground straw pellets to the feed to Lohmann Selected Leghorn (LSL) and Lohmann Brown (LB) hens housed in furnished cages between 20 and 40 wk of age. In total, 960 hens were included in the study. Droppings were collected 4 times per day for 3 consecutive days and analyzed by corticosterone immunoassay. Biological validation confirmed the ability of the assay to detect changes in FCM levels. Inclusion of straw pellets in the feed increased FCM concentration in both hen genotypes and increased excretion rate of FCM in LB hens. The LB hens also produced greater amounts of droppings than LSL hens. Both FCM levels and production of droppings varied during the day, although no distinct diurnal rhythm was found. These findings demonstrate that when using FCM to evaluate stress and welfare in laying hens, many factors (e.g., diet, genotype used, and so on) need to be taken into account to allow accurate interpretation of the results. In addition, under certain conditions, excretion rate of FCM might be more appropriate to use compared with FCM concentration.
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| 2. |
- Alm, Malin, et al.
(författare)
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Welfare and performance in layers following temporary exclusion from the litter area on introduction to the layer facility
- 2015
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Ingår i: Poultry Science. - : Elsevier BV. - 0032-5791 .- 1525-3171. ; 94, s. 565-573
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Tidskriftsartikel (refereegranskat)abstract
- When introduced to the laying facility, pullets are sometimes temporarily excluded from the litter area in order to help them locate food and water, and to prevent floor-laid eggs. This procedure is not permitted in Sweden, because it involves denying access to both litter and space, which may have a negative effect on bird welfare. The present study investigated how the welfare and performance of layers were affected by this temporary exclusion on introduction of hens to the laying facility. The study included 600 floor-reared Dekalb White layers obtained at 16wk age and housed in 6 groups of 100 in a conventional single-tier floor-laying system. Birds were either given full access to the litter area during the whole study or were excluded from the litter area during the first 2 wk after transfer to the laying facility. From 18 to 72 wk age, birds in both treatments had full access to the litter area. Excluding birds from the litter area for 2wk resulted in better feather cover and reduced fearfulness, according to novel object and tonic immobility tests. Furthermore, birds initially excluded from the litter area produced eggs with a lower proportion of shell irregularities than birds with full access to the litter area throughout. No difference was found in corticosterone metabolites in droppings rate of lay, mortality, or proportion of floor-laid eggs. In conclusion, none of the parameters studied indicated that the welfare of laying hens was compromised by temporary exclusion from the litter area on introduction to the laying facility. In fact, some of the data suggested that bird welfare had improved.
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| 3. |
- Alm, Malin, et al.
(författare)
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Welfare indicators in laying hens in relation to nest exclusion
- 2016
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Ingår i: Poultry Science. - : Elsevier BV. - 0032-5791 .- 1525-3171. ; 95, s. 1238-1247
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Tidskriftsartikel (refereegranskat)abstract
- Consumer concerns about the welfare of laying hens are increasing, leading to increased interest in identifying reliable ways to assess welfare. The present study evaluated invasive and non-invasive welfare indicators in relation to a stressful challenge. The study included 126 Lohmann Selected Leghorn hens housed in furnished cages. Welfare indicators were measured between 61 and 70 wk of age in birds excluded from their nests for 5 consecutive d and control birds that had continuous access to nests. Baseline recordings were carried out in both groups prior to and post exclusion period. The assessed indicators were: corticosterone metabolites in droppings (FCM), corticosterone concentration in yolk, corticosterone concentration in plasma, irregularities of eggshells, heterophil to lymphocyte (H:L) ratio, tonic immobility duration, and feather cover. Behavioral observations showed that the birds had a clear preference for using the secluded nest sites, confirming that they were likely to perceive nest exclusion as an undesirable experience. Further, elevated levels of FCM in droppings, yolk corticosterone concentrations, H:L ratios and irregular eggshells were detected in both nest deprived and control birds during the exclusion. This suggests that these indicators were able to detect an increased stress response arising from nest deprivation, and it is hypothesized that the stress spread to birds in adjacent cages with access to nests. There was a positive and consistent correlation between FCM in droppings and eggshell irregularities, also supporting the use of eggshell irregularities as a potential non-invasive welfare indicator. However, the pattern of the stress response varied between indicators and correlations were generally few and inconsistent, highlighting the complexity of the relationship among welfare indicators.
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| 4. |
- Bassler, Arnd, et al.
(författare)
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Potential risk factors associated with contact dermatitis, lameness, negative emotional state, and fear of humans in broiler chicken flocks
- 2013
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Ingår i: Poultry Science. - : Elsevier BV. - 0032-5791 .- 1525-3171. ; 92, s. 2811-2826
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Tidskriftsartikel (refereegranskat)abstract
- The objectives of this study were to 1) identify determinants of poor welfare in commercial broiler chicken flocks by studying the associations between selected resource-based measures (RBM, potential risk factors), such as litter quality and dark period, and animal-based welfare indicators (ABM), such as foot pad dermatitis and lameness, and 2) establish the breadth of effect of a risk factor by determining the range of animal welfare indicators associated with each of the risk factors (i.e., the number of ABM related to a specific RBM). Eighty-nine broiler flocks were inspected in 4 European countries (France, Italy, the United Kingdom, and the Netherlands) in a cross-sectional study. The ABM were contact dermatitis (measured using scores of foot-pad dermatitis and hock burn, respectively), lameness (measured as gait score), fear of humans (measured by the avoidance distance test and the touch test), and negative emotional state (measured using qualitative behavior assessment, QBA). In a first step, risk factors were identified by building a multiple linear regression model for each ABM. Litter quality was identified as a risk factor for contact dermatitis. Length of dark period at 3 wk old (DARK3) was a risk factor for the touch test result. DARK3 and flock age were risk factors for lameness, and the number of different stockmen and DARK3 were risk factors for QBA results. Next, the ABM were grouped according to risk factor and counted. Then, in a second step, associations between the ABM were investigated using common factor analysis. The breadth of a risk factor's effect was judged by combining the number (count) of ABM related to this factor and the strength of association between these ABM. Flock age and DARK3 appeared to affect several weakly correlated ABM, thus indicating a broad range of effects. Our findings suggest that manipulation of the predominant risk factors identified in this study (DARK3, litter quality, and slaughter age) could generate improvements in the related ABM and thereby enhance the birds' overall welfare status.
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| 5. |
- Berg, Lotta
(författare)
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Associations between carcass weight uniformity and production measures on farm and at slaughter in commercial broiler flocks
- 2019
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Ingår i: Poultry Science. - : Elsevier BV. - 0032-5791 .- 1525-3171. ; 98, s. 4261-4268
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Tidskriftsartikel (refereegranskat)abstract
- In poultry flocks, flock weight uniformity is often defined as the percent individuals within 10% of the mean body weight (BW) and the variability of this uniformity can be expressed as the CV of BW. Flock weight uniformity is a standardized and objective measured, and could potentially be used as a welfare indicator; however, little is known about the relationship between flock uniformity and other production measures on-farm or at slaughter. The aim of this study was to investigate the associations between carcass weight uniformity (CV of BW) and production measures on-farm and at slaughter in Norwegian commercial broiler flocks. A total of 45 randomly selected mixed-sex Ross 308 broiler flocks were visited prior to slaughter at 28 to 30 D of age (average slaughter age 30.6 D). All flocks were raised under similar farm management systems. The Welfare Quality protocol for broilers was used to assess different animal welfare indicators in each flock. All production data from the slaughterhouse were collected for each flock, including carcass weight uniformity (%), mortality (%), growth rate (g), feed conversion ratio (FCR), and rejected birds (%) in different rejection categories. Univariable and multivariable linear regression models were used to investigate the associations between flock weight uniformity and production and welfare measures. The results showed that flock uniformity varied from 11% to 18% between flocks within the same hybrid, similar management standards, and similar slaughter age (day 29 to 32). Poorer uniformity (i.e., high CV) was associated with increased first week mortality (P < 0.004, r = 1.48, increased total mortality (P < 0.013, r = 0.01), increased FCR (i.e., less efficient growth) (P < 0.024, r = 0.06), reduced growth rate (P < 0.0012, r = -0.01), and a reduced rejection rate at slaughter (P < 0.006, r = -0.01). The results show that flock uniformity varies across broiler flocks, and is associated with several production measures.
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| 6. |
- Brunberg, Emma, et al.
(författare)
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Feather pecking behavior in laying hens : Hypothalamic gene expression in birds performing and receiving pecks
- 2011
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Ingår i: Poultry Science. - : Elsevier BV. - 0032-5791 .- 1525-3171. ; 90:6, s. 1145-1152
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Tidskriftsartikel (refereegranskat)abstract
- Feather pecking (FP) is a welfare and economic problem in the egg production sector. Beak trimming, the current method used to reduce FP, is also criticized. The present study used gene expression to explore the biological mechanisms underlying this behavior, which could lead to a greater understanding of the cause and a tool to mitigate the problem. White Leghorn hens performing and receiving FP, as well as neutral control birds, were identified on a commercial farm. Hypothalamic RNA from 11 peckers, 10 victims, and 10 controls was hybridized onto GeneChip Chicken Genome Arrays (Affymetrix Inc., Santa Clara, CA) to compare gene expression profiles in the different groups. Eleven transcripts corresponding to 10 genes differed significantly between the 3 groups (adjusted P < 0.05). Eight of these transcripts differed in the peckers compared with the controls, 1 was upregulated in the victims compared with the controls, and 6 differed significantly in the peckers compared with the victims. Additionally, 5 transcripts showed a trend (adjusted P < 0.1) to differ in the pecker-victim comparison. Some of the products of the differently expressed genes are involved in disorders, such as intestinal inflammation and insulin resistance, which fit well with the previously proposed hypothesis that FP is an abnormal foraging behavior. Other findings may also support the proposal that FP is linked to immune mechanisms and may serve as an animal model for obsessive compulsive disorder in humans. In conclusion, this study provides a gene list that may be useful in further research on the mechanisms behind FP.
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| 7. |
- Chenxuan, Huang, et al.
(författare)
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Melatonin alleviates ovarian function damage and oxidative stress induced by dexamethasone in the laying hens through FOXO1 signaling pathway
- 2023
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Ingår i: Poultry Science. - 0032-5791 .- 1525-3171. ; 102
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Tidskriftsartikel (refereegranskat)abstract
- Oxidative stress can trigger follicular atresia, and decrease follicles quantity in each develop-ment stage, thereby alleviating reproductive activity. The induction of oxidative stress in chickens through intraperitoneal injection of dexamethasone is a reliable and stable method. Melatonin has been shown to miti-gate oxidative stress in this model, but the underlying mechanism remains unclear. Therefore, this study aimed to investigate whether melatonin can recover aberrant antioxidant status induced by dexamethasone and the specific mechanism behind melatonin-dependent protec-tion. A total of 150 healthy 40-wk-old Dawu Jinfeng lay-ing hens with similar body weights and laying rates were randomly divided into three groups, with five replicates per group and 10 hens per replicate. The hens in the con-trol group (NS) received intraperitoneal injections of normal saline for 30 d, the dexamethasone group (Dex +NS) received 20 mg/kg dose of dexamethasone for the first 15 d, followed by the 15 d of normal saline treat-ment. While in the melatonin group (Dex+Mel), dexa-methasone (20 mg/kg dose) was injected intraperitoneally in the first 15 d, and melatonin (20 mg/kg/d) was injected in the last 15 d. The results showed that dexamethasone treatment significantly enhanced oxidative stress (P < 0.05), while melatonin not only inhibited the oxidative stress but also notably enhanced the antioxidant enzymes superoxide dismutase (SOD), catalase activity (CAT), glutathione peroxi-dase (GSH-Px), and antioxidant genes CAT, superox-ide dismutase 1 (SOD1), glutathione peroxidase 3 (GPX3), and recombinant peroxiredoxin 3 (PRDX3) expression (P < 0.05). Melatonin treatment also markedly reduced 8-hydroxy deoxyguanosine (8-OHdG), malondialdehyde (MDA), and reactive oxy-gen species (ROS) levels (P < 0.05) and apoptotic genes Caspase-3, Bim, and Bax in the follicle. In the Dex+Mel group, the Bcl-2 and SOD1 protein levels were also increased (P < 0.05). Melatonin inhibited the forkhead Box Protein O1 (FOXO1) gene and its protein expres-sion (P < 0.05). In general, this investigation revealed that melatonin might decrease oxidative stress and ROS by enhancing antioxidant enzymes and genes, activating the antiapoptotic genes, and inhibiting the FOXO1 pathway in laying hens.
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| 8. |
- Crossley, D A, et al.
(författare)
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Effect of selection for commercially productive traits on the plasticity of cardiovascular regulation in chicken breeds during embryonic development
- 2012
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Ingår i: Poultry Science. - : Poultry Science Association. - 0032-5791 .- 1525-3171. ; 91:10, s. 2628-2636
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Tidskriftsartikel (refereegranskat)abstract
- Domesticated animal breeds have experienced profound anatomical and physiological changes as a result of human-driven genetic selection. In poultry, this selection process has resulted in many distinct phenotypes from the ancestral bird, the Red Jungle-fowl. Growth rate and egg-laying capacity are 2 traits that have been commercially prioritized, and this has resulted in a fast-growth breed, the broiler, and a prolific egg layer, the White Leghorn. In this study, we investigated basic cardiovascular physiology in these 3 breeds at 90% of incubation. We aimed to identify breed-specific features of arterial blood pressure and heart rate as well as the physiological mechanisms regulating them. Specifically, we investigated mechanisms mediated by the autonomic nervous system by means of cholinergic and adrenergic receptors. Our overriding hypothesis was that selection for rapid growth would require an acceleration of heart rate and arterial pressure development in broilers compared with White Leghorns and the ancestral breed. The embryonic broiler is characterized by resting relative hypertensive bradycardia, whereas the White Leghorn is hypotensive. All 3 breeds maintained resting arterial pressure and heart rate via a similar beta- arid alpha-adrenergic receptor tone; however, cholinergic tone on heart rate was absent in the embryonic White Leghorn. Each breed responded differently to incubation in chronic hypoxic conditions (14% O-2). White Leghorn relied on augmenting cholinergic heart rate tone, and broilers relied on reducing beta-adrenergic tone on pressure. We concluded that selection for rapid growth shifts cardiovascular regulatory plasticity to emphasize mechanisms that modulate pressure, and that selection for egg-laying capacity emphasizes mechanisms that modulate heart rate.
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| 9. |
- Dzieciolowski, Tomasz, et al.
(författare)
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Cleaning and disinfection of transport crates for poultry - comparison of four treatments at slaughter plant
- 2022
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Ingår i: Poultry Science. - : Elsevier BV. - 0032-5791 .- 1525-3171. ; 101
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Tidskriftsartikel (refereegranskat)abstract
- Transport crates for poultry can contribute to the spread of pathogens, with those of public health interest, for example, Campylobacter, being of particular importance. A strict cleaning procedure and use of an effective disinfection method for transport equipment are thus important to avoid introduction of Campylobacter to chicken and poultry farms, particularly during flock thinning. This study evaluated the efficacy of the disinfection procedure currently in use at one of the largest slaughter plants in Sweden and compared the effects with those of other disinfection methods. The evaluation was based on treatment ability to reduce the presence and amount of indicator bacteria belonging to the family Enterobacteriaceae and total aerobic bacteria. In 4 trials, sodium hypochlorite, peracetic acid, and drying with hot air, with or without sodium hypochlorite for final disinfection, were compared. The analysis was based on 40 cotton swab samples taken in each treatment, 20 after the soaking stage and 20 after the final disinfection step.The results showed that use of a chemical disinfectant in combination with drying with hot air (dehumidifier) was the most effective treatment, with an average reduction of 3.4 log for total aerobic bacteria and 3.8 log for Enterobacteriaceae. Since all crates treated with hot air were dry, transport conditions for the birds also improved, particularly in cold weather. A disadvantage is that this treatment is energy-consuming and would require substantial technical changes to the current cleaning process, increasing operating costs at the slaughter plant. However, considering the contribution of improved crate cleaning to overall hygiene control within the poultry supply chain and the beneficial effect on animal welfare, the costs may be justified.
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| 10. |
- Gunnarsson, Stefan
(författare)
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Associations between neck plumage and beak darkness, as well as comb size measurements and scores with ranging frequency of Sasso and Green-legged Partridge chickens
- 2021
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Ingår i: Poultry Science. - : Elsevier BV. - 0032-5791 .- 1525-3171. ; 100
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Tidskriftsartikel (refereegranskat)abstract
- Despite the intensive genetic selection in modern poultry, variability of domestic fowl phenotypes has remained, especially in breeds adapted to local conditions. The relevance of this variability to the chicken outdoor ranging activities remains unknown. The aim of this study was to investigate if external features were associated with the ranging frequency of the 48 female chickens from each of the 2 breeds: Sasso and Green -legged Partridge. In each of 6 single-breed pens, 8 hens and 2 roosters were housed under conditions of EU requirements for organic meat chicken production, including free access to an outdoor range, from wk 5 to 10 of age. The birds were video-recorded during the experiment to obtain frequencies of individual birds' use of the ranges. Comb size (length and height) was measured using a digital ruler, while the sizes of the dark area of neck plumage and beak were processed and analyzed using ImageJ software. The same traits were scored using direct visual assessment by a trained observer on a scale of 1-3. In addition, the eye color of the bird was recorded. Statistical analysis was conducted independently for each breed using regression models, ANOVAs and Spearman correlations. Significant positive associations between neck plumage (P < 0.01), beak darkness (P = 0.03) measurements, comb length (P < 0.01) and comb height (P < 0.01) and frequency of range use were identified for Sasso. Sasso hens scored with darkest neck plumage (P = 0.03) and biggest comb size (P = 0.04) ranged the most, while their external features were significantly and positively correlated between each other, except beak darkness and comb length. No significant associations between ranging and external features were found in Green-legged Partridge birds, except that their comb height was significantly and positively correlated with neck plumage and beak darkness (r = 0.39 and 0.33, respectively). In some genetic strains, better understanding of the associations between chickens' external features with ranging behavior could contribute to improve selection programs and bird welfare, assuring production of breeding stock suitable for outdoor conditions.
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