Contrafreeloading and foraging-related behavior in hens differing in laying performance and phylogenetic origin

Different breeds of domestic and junglefowl differ in foraging strategies indicating that domestication resulted in modified energy saving behavioral strategies. In the present study we investigated foraging strategies and foraging-related behavior in 4 lines of laying hens differing in phylogenetic origin and laying performance to analyze a possible relationship between foraging and the level of egg production. High performing brown and white pure bred lines were compared with their low performing brown and white counterparts. To control possible effects on behavior other than genetic effects, all hens were reared and kept in an identical environment. A total of 72 hens from each line were kept in 6 compartments with 12 hens per compartment, respectively. Observations were done for 3 times during one laying period. Foraging strategy was tested by a contrafreeloading (CFL) paradigm. CFL describes a behavior in which animals prefer food that requires effort to obtain, although at the same time food is freely available. The hens were offered a commercial standard diet in one trough and a mixture of wood shavings and commercial standard diet in another trough. The behavior of hens was video recorded and the activity level of individual hens in the litter area was recorded by an antenna-transponder system. The high performing layers showed less CFL and foraging-related behavior compared with their low performing counterparts in both the white and brown layers. Despite differences in CFL, all hens showed a preference for the commercial standard diet compared to the mixture of wood-shavings. Our results show an association between foraging strategy and level of egg production. This suggests that a high level of egg production is accompanied by behaviors enabling the hens to satisfy their higher energy demand more efficiently. Saving energy by reduced activity probably allows them to reallocate energy into reproduction, that is, laying performance.

Daily energy expenditure and water turnover in two breeds of laying hens kept in floor housing

Laying hens are increasingly kept in barn or free-range systems, which not only allows birds to move freely but also potentially entails higher energy expenditures due to higher locomotor activity. Therefore, the aim of our study was to quantify the daily energy expenditure (DEE) and water turnover in freely moving laying hens. For that purpose, 10 Lohmann Selected Leghorn (LSL) and 10 Lohmann Brown (LB) hens were obtained from a conventional breeding company at 17 weeks of age. The trial started when birds reached an age of 34 weeks. All 20 birds were kept together in the same littered floor pen (12.1 m²). The pen was equipped with perches, a nest box, feeding and nipple drinkers. The DEE was determined individually for all experimental birds (n = 20) for a total of nine days using the doubly labelled water (DLW) method. Lohmann Brown hens were heavier than LSL hens, but laying rate did not differ between the two breeds, that is, one egg per hen and day during the study period. Average egg mass was 63.1 ± 0.20 g in LB and 61.7 ± 0.12 g in LSL hens, which converted to an egg energy content of 420 and 410 kJ/egg, respectively. Dilution spaces for oxygen and hydrogen differed between the breeds but not the respective turnover rates. Total body water as a percentage of body mass (LB: 54.4%, LSL: 53.8%; SEM = 0.7, F_1,18 = 0.41, P = 0.513) and total water intake (TWI) per day (LB: 275 ml/day, LSL: 276 ml/day; SEM = 20, F_1,17 = 0, P = 0.994) did not differ between LB and LSL hens. Individual DEE increased with body mass in LB but not in LSL hens. Average DEE did not differ between the two breeds (LB: 1501 kJ/day; LSL: 1520 kJ/day; SEM = 32.1, F_1,17 = 2.54, P = 0.131). However, when comparing the DEE on a metabolic mass basis, LSL hens expended with 984 kJ/kg^0.75 on average significantly more energy per day than LB hens (895 kJ/kg^0.75; SEM = 20.3, F_1,18 = 10.1, P = 0.005). Our results suggest that the DLW technique is a viable method to measure the energy expenditure and water turnover over several days in laying hens. Furthermore, we show that laying hens kept in floor pens fit into the general pattern of DEE among wild birds.

Research Note: Injurious pecking in fattening turkeys (Meleagris gallopavo f. dom.)-video analyses of triggering factors and behavioral sequences in small flocks of male turkeys

Injurious pecking is one of the main welfare issues in fattening turkey husbandry. Birds pecked by conspecifics can suffer from serious injuries that may even lead to the death of the victimized animals or require their culling. In the present study, the behavior of male turkeys was documented day and night using video recordings throughout the entire fattening period of 19 wk. Thus, when a turkey was found injured or dead in the barn, a retrospective analysis of video recordings was carried out to clarify the circumstances surrounding the death or injuries of the bird in the present study. In 3 fattening trials with a total of 1,620 male turkeys with intact beaks, 41 birds (2.5%) were found either seriously injured (n = 24) or dead (n = 17) in the barn as a result from conspecific pecking. The detailed evaluation of the video recordings showed that the onset of injurious pecking was mainly in the afternoon after the last daily visual controls of animals and that one third of the dead found animals died a natural death without any pecking incidents. The duration of injurious pecking directed against a certain conspecific was on average 794 min, ranging from 84 min to 1,437 min, that is up to almost an entire day. Pecking activities lasting more than 10 h were interrupted from the light regime between dusk and dawn but continued with the onset of light in the morning. Duration of injurious pecking events decreased with age (P = 0.031). If the victims laid down or were impaired in their mobility, they would be surrounded by up to 10 turkeys that would still be forcefully pecking at the occipital and neck area of the badly injured or moribund birds.

Is the rotarod test an objective alternative to the gait score for evaluating walking ability in chickens?

Walking ability is related to motor co-ordination which, in rodents, can be assessed by an established test in pharmacological studies — the rotarod test. The purpose of this study was to evaluate a modified rotarod test for chickens and its relation to the often-used gait score system. At the end of their rearing period, we tested 138 male chickens (Gallus gallus domesticus) from three differing growth performance strains: Ross 308 (fast-growing; n = 46), Lohmann Dual (medium-growing; n = 46) and Lohmann Brown Plus (slow-growing; n = 46). First, the chickens gait scores were assessed and, immediately following this, they were placed gently onto a steady rod. The velocity of the rotating rod gradually increased, and the latency to leave the rod was recorded. By using a linear mixed model, we were able to show that the latency to leave the rotating rod was significantly predicted by the gait score. Fast-growing chickens had shorter durations on the rotating rod, and these durations were associated with gait score. We conclude that the rotarod test provides an objective alternative method for assessing walking ability in chickens without the need for intense observer training or the risk of observer biases and propose that this novel methodology has the potential to function as a precise, objective indicator of animal welfare.

Perches or grids? What do rearing chickens differing in growth performance prefer for roosting?

The domestic fowl (Gallus gallus f. dom.) is highly motivated to roost on elevated structures. Previous studies indicated that broiler chickens hardly use elevated perches but frequently use elevated platforms. However, it is unclear which height and type of elevated structures broilers prefer at various daytimes.We investigated the use of elevated perches and grids varying in height (10, 30, and 50 cm above the floor) by chickens of 3 strains differing in growth performance. In 2 successive trials, male chickens of Ross 308 (Ross, fast growing, n = 200), Lohmann Dual (Dual, medium growing, n = 200), and Lohmann Brown Plus (LB, slow growing, n = 200) were tested in 12 experimental compartments (each strain in 4 compartments), respectively. Usage of structures was recorded on video and analyzed with time-sampling observation for each week of age during dawn, the light period, dusk, and the dark period. In addition, behavioral activity was measured with an antenna-transponder system.The results showed that Ross and Dual chickens preferred grids to perches throughout the entire observation period. With increasing age, chickens of all strains increasingly used the elevated structures during all daytimes. In contrast to Dual and LB, Ross chickens reduced the use of structures from the 3rd to 4th week of age during the light but not the dark period. Additionally, during the dark period, chickens of all 3 strains at the end of fattening period used elevated structures at 50 cm height most often. The behavioral activity decreased significantly in all 3 strains but was much lower in Ross chickens compared with Dual and LB.The results indicated that chickens are motivated to roost at nighttime on high-elevated and suitable structures such as grids. Further studies are needed to assess the space requirements for elevated structures that should be offered to chickens.

High, low, or familiar? Nest site preferences of experienced laying hens

1. The aim of this study was to investigate which nest heights are preferred by laying hens in the absence of familiar nest locations and whether preferred nest heights are more attractive than a familiar location. In two experiments, a total of 108 hens of four different layer breeds, which were at least 50 weeks of age, were studied. 2. In the first experiment, hens were given individual free choice between nests for 1-week at four different heights (0 cm, 39 cm, 78 cm, and 117 cm above ground). Hens of the four breeds differed in their nest height preferences (P = 0.0013). However, hens of three breeds preferred ground level nests (P < 0.007) and the fourth line showed an equal preference for the ground level and level three, the latter level corresponding to the height of the nests in their home compartments. 4. In the second experiment, hens from the four breeds were given a choice between ground level nests and nests at a familiar location, i.e. at the same location as in their home compartment. Hens of all strains preferred the familiar nest location (P = 0.002) and preferences did not differ between strains (P = 0.77). 5. Laying hens seem to prefer nests at ground level in the absence of a familiar nest. However, if possible, experienced 50 week old hens continue to use a familiar nest location instead of a ground nest location. The results are discussed with respect to a potential primary preference that may be modifiable by experience and with respect to possible relevance in commercial housing.

Ghrelin plasma concentration does not covary with energy demand in adult laying hens

The peptide hormone ghrelin is suggested to be involved in food intake regulation in young growing chicken. Whether ghrelin is involved in the regulation of energetic balance associated with laying performance in adult laying hens was studied by use of 4 chicken lines that differ in laying performance and phylogeny (4 lines; 16 hens per line). As housing conditions are also known to affect energy demand, half of the hens per line were housed in single cages and the other half of hens were maintained in a floor housing system. Plasma samples were collected at 17 to 19, 33 to 35, 49 to 51, and 72 wk of age and analyzed with a chicken ghrelin ELISA Kit. From caged hens, individual food consumption and laying performance additionally was recorded. Due to its function in growth and its relationship with ghrelin, also GH plasma concentrations were analyzed. Ghrelin concentrations did not differ between the 4 lines at any of the test periods (all P > 0.05). Ghrelin was negatively related to food consumption only in the growing period of the high-performing lines (both P < 0.0001). During this phase, floor-housed hens showed greater ghrelin concentrations compared with caged hens (P < 0.0001). Our results suggest that in adult layers ghrelin is not involved in regulating energy intake related to laying performance but rather seems to be related to body growth and housing condition before start of lay, the latter possibly due to differences in hens' behavioral activity.

Determination of body width in brown and white layer pullets by image analyses

1. Specific legal requirements for keeping pullets are not available in the European Union. However, two of the most important rearing factors for pullets are sufficient perching and feeder space. Both factors represent horizontal space dimensions which derive from the body width of the birds. 2. The body width of two strains of layer pullets (brown (BL) and white (WL) layer pullets) based on the measurement of distances in digital images was conducted on front-view digital photographs of BL and WL pullets taken at 8, 12 and 19 weeks of life. 3. Depending on live weight, age and body position, BL pullets measured an average body width between 10.70 ± 1.10 and 13.96 ± 1.11 cm. The width of WL pullets ranged from 10.30 ± 0.86 to 13.00 ± 1.14 cm. 4. Compared with WL, BL pullets occupied more horizontal space during rearing. Age influenced the body width of BL and WL pullets at the end of rearing. The tested body positions of the pullets did not affect the measured body width. 5. The biometric data obtained in this study are a useful basis for developing legal requirements for pullets, especially for defining minimum perch width and feeder space allowances.

Interobserver reliability of the 'Welfare Quality(®) Animal Welfare Assessment Protocol for Growing Pigs'

The present paper focuses on evaluating the interobserver reliability of the 'Welfare Quality(®) Animal Welfare Assessment Protocol for Growing Pigs'. The protocol for growing pigs mainly consists of a Qualitative Behaviour Assessment (QBA), direct behaviour observations (BO) carried out by instantaneous scan sampling and checks for different individual parameters (IP), e.g. presence of tail biting, wounds and bursitis. Three trained observers collected the data by performing 29 combined assessments, which were done at the same time and on the same animals; but they were carried out completely independent of each other. The findings were compared by the calculation of Spearman Rank Correlation Coefficients (RS), Intraclass Correlation Coefficients (ICC), Smallest Detectable Changes (SDC) and Limits of Agreements (LoA). There was no agreement found concerning the adjectives belonging to the QBA (e.g. active: RS: 0.50, ICC: 0.30, SDC: 0.38, LoA: -0.05 to 0.45; fearful: RS: 0.06, ICC: 0.0, SDC: 0.26, LoA: -0.20 to 0.30). In contrast, the BO showed good agreement (e.g. social behaviour: RS: 0.45, ICC: 0.50, SDC: 0.09, LoA: -0.09 to 0.03 use of enrichment material: RS: 0.75, ICC: 0.68, SDC: 0.06, LoA: -0.03 to 0.03). Overall, observers agreed well in the IP, e.g. tail biting (RS: 0.52, ICC: 0.88; SDC: 0.05, LoA: -0.01 to 0.02) and wounds (RS: 0.43, ICC: 0.59, SDC: 0.10, LoA: -0.09 to 0.10). The parameter bursitis showed great differences (RS: 0.10, ICC: 0.0, SDC: 0.35, LoA: -0.37 to 0.40), which can be explained by difficulties in the assessment when the animals moved around quickly or their legs were soiled. In conclusion, the interobserver reliability was good in the BO and most IP, but not for the parameter bursitis and the QBA.

Haematological and febrile response to Escherichia coli lipopolysaccharide in 12-week-old cockerels of genetically diverse layer lines fed diets with increasing L-arginine levels

Due to its decisive function in the avian metabolic, endocrine and immune system L-arginine (Arg) is dietary indispensable for chickens. In 12-week-old cockerels of two high- and two low-performing purebred layer lines, the effects of increasing dietary Arg on the haematological and febrile response were studied over 48 h after single lipopolysaccharide (LPS) injection. The offered diets contained Arg equivalent to 70%, 100% and 200% of recommended supply. Pathophysiological alterations in weight gain, feed intake, body temperature and differential blood count were examined in comparison with their physiological initial values. Within the first 24 h after LPS injection, cockerels reduced feed intake and lost body weight subsequently. Thereby, low-performing genotypes lost body weight to a lesser extent than high-performing ones. The loss of body weight was further intensified by deficient dietary Arg. Within the following 24 h, cockerels recovered by improving feed intake and weight gain. Furthermore, LPS induced genotype-specific fever response: both brown genotypes showed initial hypothermia followed by longer lasting moderate hyperthermia, whereas the white genotypes exhibited biphasic hyperthermia. Fever response was accompanied by significant changes in differential blood counts. Characterized by lymphopenia and heterophilia, a severe leucopenia was observed from 4 to 8 h after LPS injection and replaced by a marked leucocytosis with longer lasting monocytosis up to 48 h after LPS injection. Under given pathophysiological conditions, deficiently Arg-supplied cockerels showed higher total leucocyte counts than adequately and excessively Arg-supplied cockerels. However, deficient and surplus dietary Arg tended to cause higher ratios between heterophils and lymphocytes. To conclude, present results confirmed that LPS induced numerous immunological changes in 12-week-old cockerels and emphasized that chicken's genotype is a source of variation to be considered for immunological studies. Deficient dietary Arg intensified acute changes in differential blood counts and weight gain during LPS-induced inflammation.

Training veterinarians and agricultural advisers on a novel tool for tail biting prevention

Introduction

Many health and welfare problems in modern livestock production are multifactorial problems which require innovative solutions, such as novel risk assessment and management tools. However, the best way to distribute such novel - and usually complex - tools to the key applicants still has to be discussed.

Materials and methods

This paper shares experiences from distributing a novel tail biting prevention tool (‘SchwIP’) to 115 farm advisers and 19 veterinarians in 23 one-day workshops. Participants gave written and oral feedback at the end of the workshops, which was later analysed together with the number of farms they had visited after the workshops. Workshop groups were categorised into groups showing (a) HIGH, (b) INTermediate or (c) LOW levels of antagonism against SchwIP or parts of it during workshop discussions.

Results

Group types did not significantly differ in their evaluation of knowledge transfer. However, HIGH group members evaluated the on-farm usability of the tool significantly lower in the workshop feedback and tended to visit fewer farms.

Conclusions

As antagonistic discussion can influence workshop output, future workshop leaders should strive for basic communication training as well as some group leadership experience before setting up and leading workshops.

Methods for assessment of keel bone damage in poultry

Keel bone damage (KBD) is a critical issue facing the laying hen industry today as a result of the likely pain leading to compromised welfare and the potential for reduced productivity. Recent reports suggest that damage, while highly variable and likely dependent on a host of factors, extends to all systems (including battery cages, furnished cages, and non-cage systems), genetic lines, and management styles. Despite the extent of the problem, the research community remains uncertain as to the causes and influencing factors of KBD. Although progress has been made investigating these factors, the overall effort is hindered by several issues related to the assessment of KBD, including quality and variation in the methods used between research groups. These issues prevent effective comparison of studies, as well as difficulties in identifying the presence of damage leading to poor accuracy and reliability. The current manuscript seeks to resolve these issues by offering precise definitions for types of KBD, reviewing methods for assessment, and providing recommendations that can improve the accuracy and reliability of those assessments.

Analysis of landing behaviour of three layer lines on different perch designs

1. The prevalence of keel bone deformities in laying hens is high and is partly associated with unsuitable perch designs, which impose a risk of injury due to an unstable footing. 2. Over two experiments, 9 or 10 hens of each of three layer lines (Lohmann Selected Leghorn (LSL), Lohmann Tradition (LT) and Lohmann Brown (LB)) were filmed while landing on three different perch types, including steel perches of various diameters, a commercial mushroom-shaped plastic perch and a newly developed prototype perch with a soft surface material. 3. Data on landing behaviour (safe vs. unsafe or failed landing) following downward jumps were collected for 25, 50 and 60 cm vertical distances and 75 cm horizontal distance between a wooden start perch and the different destination perches. 4. The highest proportion of safe landings occurred on the prototype perch, whereas least safe landings were observed on steel perches, irrespective of their diameter. The mushroom-shaped perch was intermediate with regard to the safeness of landing. 5. A threshold of 50 cm vertical distance (34° slope) was identified as the optimum for downward jumps on perches in order to reduce the risk of unsafe or failed landings. Above this threshold, the proportion of safe landings declined significantly. 6. Brown shell layer types (LB and LT) had a lower proportion of safe landings compared to the white shell layer type (LSL), whereas no difference was found between LB and LT layer lines. 7. Although steel perches prevail in commercial housing, these perches were found to be least advantageous with regard to landing behaviour. The prototype perch provided the most stable footing on perching and is a promising alternative to replace commercial steel perches, thus helping to reduce the risk of perch-related keel bone injury.

Pressure load on specific body areas of gestating sows lying on rubber mats with different softness

Rubber mats offer a possibility to increase lying comfort for sows with positive effects on sow lying behavior and health. However, until now, no information has been reported about the relationship between the softness of rubber mats and the pressure load on certain body areas of sows. We used a total of 68 (40 multiparous, 28 primiparous) German Landrace × German Landrace sows with a BW within the range of 90 to 330 kg (divided in 3 weight classes) to measure peak force and distribution of pressure during lying in the sternal and half recumbent position. Measures were done in an experimental pen that was equipped with a pressure sensor map system (5400 NTL; Tekscan Inc., Boston, MA). Three rubber mats differing in softness (penetration depth: hard mat, 4.0 mm [HM]; soft mat, 14.6 mm [SM]; very soft mat, 43.0 mm [VSM]) were tested and compared to concrete floor (CF) as a reference. Pressure load was analyzed in the sternal position for the sternum, belly, and ham body regions and also in the half recumbent position for the shoulder. For each lying position we determined the body region with the highest pressure load and analyzed the peak force (PF) and the contact area (CA) using a mixed model ANOVA (MIXED procedure of SAS Enterprise, version 4.3., SAS Inst. Inc., Cary, NC) with floor type, weight class of sows, and their interaction as fixed factors. Overall, the highest values for PF in the sternal position were found on the sternum (median: 1.62 N/cm(2)) and in the half recumbent position on the shoulder (median: 2.72 N/cm(2)). In the sternal position PF on the sternum was lower on VSM compared to CF (P = 0.001). In the half-recumbent position PF on the shoulder was lower on VSM compared to CF (P = 0.013) and compared to HM (P = 0.011). The weight of the sows affected PF on the sternum in the sternal position, with lower values in weight class 1 compared to weight class 2 (P = 0.001) and weight class 3 (P = 0.002). Contact area under the sternum was larger on SM (P = 0.016) and VSM (P = 0.008) compared to CF in the sternal position, and this was affected by weight class (P = 0.0002). In the half-recumbent position floor type did not affect CA under the shoulder, but CA was larger in weight classes 2 and 3 compared to weight class 1 (all P < 0.05). Assuming that a reduced PF in combination with pressure distributed over a larger area will increase lying comfort, hard rubber mats do not seem to offer a high lying comfort with regard to pressure load on debited body regions such as the sternum or shoulder.

Dustbathing in food particles does not remove feather lipids

Within the European Union, dustbathing material in cage-housing systems for laying hens became compulsory in 2012. In practice, most producers use food particles as litter substrate. The feed is dropped in small amounts on scratching mats by an automatic transporting system. However, because dustbathing behavior is meant to remove stale lipids from hens' plumage, food particles may not be a suitable substrate due to their fat content. This study analyzes feather lipid concentration (FLC) of laying hens with access to food particles (F) or lignocellulose (L) as litter substrates. In each of 2 identical trials, 84 laying hens of 2 genotypes (Lohmann Selected Leghorn, Lohmann Brown) were kept in 12 compartments (7 hens each). Compartments were equipped with a grid floor and additionally contained a closed dustbathing tray holding F or L. Feather samples (150 feathers) were taken 2 times throughout the experiment. At 23 wk of age, 4 hens per compartment were sampled after they were allowed pair-wise access to a dustbath for 2.5 h and 3 hens were sampled without access to a dustbathing tray (control). After 10 wk of free access to the dustbathing trays, all hens were sampled again. In trial 2, an additional third sampling was made after dustbaths had been closed again for 6 wk. Here, 6 hens per compartment were sampled immediately before and after a dustbath. Dustbathing in F resulted in higher FLC compared with L and control (P < 0.001), whereas no significant difference was found between L and control (P = 0.103). When open access to litter was provided, hens had higher FLC in F compared with L (P < 0.001). The FLC immediately after dustbathing in F was higher compared with the level before dustbathing (P < 0.001), whereas it was lower after dustbathing in L (P = 0.006). These results show that F are not suitable litter material for laying hens because they lead to lipid accumulation on the plumage.

Litter lipid content affects dustbathing behavior in laying hens

Within the European Union, the provision of dustbathing material in layer housing systems will be compulsory beginning in 2012. In cage systems, food particles are mainly used as litter material and are provided on scratching mats by an automatic transporting system. However, because dustbathing is a means for hens to remove stale lipids from their plumage, lipid content of a substrate may be an important asset with regard to its adequacy. This study analyzes dustbathing behavior as affected by lipid content of feed used as litter material. A total of 72 laying hens of 2 genotypes (Lohmann Selected Leghorn, Lohmann Brown) were kept in 12 compartments (6 hens each). Compartments were equipped with a plastic grid floor (G) and additionally contained 3 different dustbathing trays (each 1,000 cm(2)/hen) holding low-lipid (0.82%; L), normal-lipid (4.2%; N), and high-lipid (15.7%; H) food particles. The experiment began at 20 wk of life, and video recordings were done at wk 23, 26, and 29. Number of dustbaths, time spent dustbathing, average dustbath duration, foraging, and single behaviors within dustbaths were analyzed during the light period over 2 d in each observation week. Dustbaths occurred most frequently in the L compared with the N, H, and G treatments (all P < 0.001). Total time spent dustbathing was longest in the L treatment compared with the N and H treatments (P < 0.001). No difference in the average duration of single dustbaths was found between the L, N, and H treatments. However, when dustbath interruptions (less than 10 min) were excluded, the duration of single dustbaths was longer in the H compared with the L (P = 0.009) and N (P = 0.024) treatments. Foraging was most frequently observed in the N compared with the L, H, and G treatments (all P < 0.001). More body wing shakes occurred in the L compared with the N treatment, and the number of vertical wing shakes was higher in the N compared with the H treatment (all P ≤ 0.05). Our results showed that preference for a dustbathing substrate increased with decreasing lipid content, implying that food particles may not be a suitable dustbathing substrate.

Application of machine learning methodology for PET-based definition of lung cancer

We applied a learning methodology framework to assist in the threshold-based segmentation of non-small-cell lung cancer (nsclc) tumours in positron-emission tomography–computed tomography (pet–ct) imaging for use in radiotherapy planning. Gated and standard free-breathing studies of two patients were independently analysed (four studies in total). Each study had a pet–ct and a treatment-planning ct image. The reference gross tumour volume (gtv) was identified by two experienced radiation oncologists who also determined reference standardized uptake value (suv) thresholds that most closely approximated the gtv contour on each slice. A set of uptake distribution-related attributes was calculated for each pet slice. A machine learning algorithm was trained on a subset of the pet slices to cope with slice-to-slice variation in the optimal suv threshold: that is, to predict the most appropriate suv threshold from the calculated attributes for each slice. The algorithm’s performance was evaluated using the remainder of the pet slices. A high degree of geometric similarity was achieved between the areas outlined by the predicted and the reference suv thresholds (Jaccard index exceeding 0.82). No significant difference was found between the gated and the free-breathing results in the same patient. In this preliminary work, we demonstrated the potential applicability of a machine learning methodology as an auxiliary tool for radiation treatment planning in nsclc.

Pressure load on keel bone and foot pads in perching laying hens in relation to perch design

The provision of perches in housing systems for laying hens is meant to improve hens' welfare by allowing a more natural behavior repertoire. However, the use of perches is associated with welfare problems, such as keel bone deviations and foot pad lesions, that may possibly result from high mechanical pressure load during extended perching activities. The aim of this study was to analyze peak force and contact area of hens' keel bones and foot pads on solid test perches of square, round, and oval shape with 3 different diameters each (experiment 1) and on commercially used perches (round steel tube, 2 sizes of mushroom-shaped plastic, and flattened round plastic) together with 2 prototypes of soft, round polyurethane perches (experiment 2). Test perches were covered with a pressure sensor film and 36 laying hens (18 Lohmann Selected Leghorn, 18 Lohmann Brown) were consecutively placed on each perch in an experimental cage during nighttime. Peak force (N/cm(2)) and contact area (cm(2)) were measured while hens were sitting and standing on the different test perches. Pressure peaks on the keel bone were approximately 5 times higher compared with single foot pad. On square perches, keel bone peak force was lower (P < 0.05) and contact area was larger (P < 0.001) compared with round and oval perches. In addition, peak force on foot pads in standing hens was higher on square perches (P < 0.05) compared with oval perches. Perch size did not affect peak forces on keel bones in sitting hens and foot pads in standing hens (experiment 1). On prototype perches, peak force on the keel bone was lower and contact area was larger compared with all commercial perches tested (P < 0.001). Peak force on foot pads was lower on prototype perches compared with steel perches (P < 0.01; experiment 2). Perches with a soft surface may possibly reduce keel bone and foot pad welfare problems in perching laying hens.

Food, wood, or plastic as substrates for dustbathing and foraging in laying hens: A preference test

The provision for dustbathing material will be a legal requirement in cage-housing systems for laying hens within the European Union beginning in 2012. At present, food particles are widely used and typically offered in small amounts on Astroturf mats one or more times per day to facilitate dustbathing, pecking, and scratching. In the present study, we compared layers' preference for food and 3 other (nonnutritive) substrates for foraging and dustbathing. In each of 2 identical trials, 72 hens of 2 genotypes (Lohmann Selected Leghorn and Lohmann Brown) were kept in 12 compartments (6 hens each). Compartments were equipped with a plastic grid floor and additionally contained 4 different dustbathing trays (each 1,000 cm(2)/hen) holding either wood shavings (WS), lignocellulose (LN, soft wood fiber, pelleted), Astroturf mat without substrate (AT), or food particles (FP). Hens were housed from 18 wk of age and video recordings were done at wk 21, 24, and 27. Time spent and frequency of dustbathing, duration of a single dustbath (DB), frequency of foraging behavior, and relative frequency and duration of behavioral patterns within a single DB were recorded during the light period over 2 d in each observation week. The FP treatment was preferred for foraging over WS, LN, and AT. Time spent dustbathing and number of DB were higher in LN compared with WS, FP, and AT, whereas average duration of a single DB was longer in FP compared with LN and WS. More vertical wing shakes and scratching bouts within a single DB were observed in LN compared with AT. Bill raking occurred more frequently in WS and LN in comparison to FP and AT. No differences in the relative durations of behavioral patterns within a single DB were found. In conclusion, FP were preferred for foraging but not for dustbathing, indicating that FP may not be an optimal dustbathing substrate for laying hens.

Storage of neutrophil granulocytes (PMNs) in additive solution or in autologous plasma for 72 h

Neutropenia may necessitate polymorphonuclear (PMN) transfusion, but among other reasons, PMN short shelf-life complicates realization of innovative transfusion strategies. In 18 donors, PMNs were mobilized using rHuG-CSF + dexamethasone. (8.3 +/- 1.6) x 10(10) PMNs were harvested in 203 +/- 8.7 mL. PMNs were stored undiluted (1, n = 18) and diluted 1-in-2, 1-in-4, 1-in-8 using T-Sol (2, n = 6), T-Sol + 1% HSA (3, n = 6), or autologous plasma (4, n = 6) for 72 h. Haemograms, pH values, phagocytosis, oxidative burst, and interleukin (IL)-1beta, IL-8 and tumour necrosis factor (TNF)-alpha levels were assessed every 24 h. PMN count decreased from (4.3 +/- 0.8) x 10(10) to (2.2 +/- 1.0) x 10(10), and pH value dropped from 6.4 +/- 0.3 to 5.4 +/- 0.2 within 72 h (1), whereas 1-in-4 and 1-in-8 dilutions exhibited consistent haemograms and pH values above 6.0. 1-in-8 dilution (4) stabilized pH at 7.1 +/- 0.4 after 72 h. Function deteriorated to about 50% within 24 h (1), but 1-in-8 (3), 1-in-4 and 1-in-8 diluted PMNs (4) kept it >90% for 72 h. In all collectives, cytokine levels increased during storage. After all, IL-1beta ranged between 31.0 +/- 16.3 (1-in-4, 4) and 100.0 +/- 21.4 (1-in-4, 2), IL-8 from 513 +/- 454 (1) to 3180 +/- 760 (1-in-8, 2), and TNF-alpha between 3.8 +/- 1.7 (1-in-2, 2) and 23.2 +/- 11.8 (1-in-8, 4) (pg mL(-1)). PMN function may be preserved for 72 h in vitro by dilution of PMN apheresates with, preferably, autologous plasma.

Individual Consistency of Dairy Cows’ Activity in Their Home Pen

The aim of this research was to investigate the long-term individual consistency of dairy cow activity in the home pen. Activity in a loose-housing barn was examined in 35 Holstein-Friesian dairy cows using an automatic monitoring system. Different amounts of activity could be distinguished by dynamic thresholds. Subsequently, the following categories of activities were calculated as mean daily values: number of high activity counts (NHA), number of low activity bouts (NLB), and mean duration of low activity bouts (DLB). Category NHA reflects locomotor behavior, and NLB and DLB reflect resting behavior. Recordings were repeated 4 times during a period of 2 lactations for 10 d each (total observation time: 40 d). Effects of parity, week of lactation, and environmental conditions (light intensity and ambient temperature) on activity were also assessed. Our results reveal a high degree of consistency in individual cow activity throughout 2 lactations. Repeatability (REP), calculated using covariance parameters, was high for all traits, although the REP of NHA (REP = 0.62) was higher than the REP of NLB (0.40) or DLB (0.49). Parity, week of lactation, and environmental conditions had no significant effects on activity. In conclusion, our results indicate that activity of dairy cows in their home pen was highly consistent over time, and thus, could be considered as individual traits.

A laser-based method to measure thermal nociception in dairy cows: short-term repeatability and effects of power output and skin condition

To validate a laser-based method to measure thermal nociception in dairy cows (e.g., for the use in studies on stress-induced analgesia), we performed three experiments to observe the behavioral responses to a computer-controlled CO2 laser beam applied to the skin on the caudal aspect of the metatarsus. In Exp. 1, effects of power output (0, 1.3, 1.8, 2.2, 2.4 and 2.6 W) on nociceptive responses were examined using 18 dairy cows kept and tested in tie stalls. Increasing the power output affected the latencies to respond (decreasing latencies, P < or = 0.01), types of response (less nonresponding and more kicking, P < 0.0001), and behavior during (increasing frequency of tail flicking, P = 0.003) and between single laser exposures (increasing frequency of kicking, P = 0.02). Therefore, behavioral responses to a laser stimulus seem to be a valid measure of nociception in dairy cows. Repeatability within 15 min was investigated in Exp. 2 using n = 36 dairy cows kept and tested in tie stalls and a power output of 1.8 W. The variables' latency to move the exposed leg and frequency of tail flicking during laser exposure showed the highest level of repeatability (0.50 and 0.38, respectively). However, retesting at t = 15 min led to increased responses in terms of shorter latencies to respond (P < 0.05), increased kicking (P = 0.05), and tail flicking (P = 0.02), which probably can be explained by sensitization. Effects of power output (1.0 vs. 1.8 W) and skin condition (naked vs. intact) were examined in Exp. 3 on 11 group-housed dairy cows, tested just outside their home pen. Increasing the power output and shaving off hair led to increased responses as seen by shorter latencies to respond (P < 0.0001), less nonresponding (P < 0.0001), and increased kicking (P = 0.0003), as well as reduced intra- and interindividual variability (P < or = 0.04). In conclusion, the results of these experiments suggest that behavioral responses to laser stimulation are a valid and reliable measure of nociception in dairy cows, especially when applied on naked skin, both in the home environment and just outside a group pen. The fact that repeated testing in itself at t = 15 min led to increased responses means that the test will be a conservative measure of stress-induced analgesia.

Temporal differences in the responses of the pituitary adrenocortical axis, the sympathoadrenomedullar axis, heart rate, and behaviour to a daily repeated stressor in domestic pigs

In this study we examined responses of domestic pigs (Sus scrofa domestica) to a daily repeated stressor. In particular, we focused on differences in temporal changes across treatment repetition between the pituitary adrenocortical axis, the sympathoadrenomedullar axis, heart rate, and behaviour. To induce a stress response, we separated eight castrated male pigs from their group mates visually and auditorily for 1 h on 10 successive days. Overall, enhanced plasma levels of cortisol, ACTH, and adrenaline indicated a clear stress response. Levels of cortisol and ACTH decreased continuously with repetition of exposures to the stressor. In contrast, levels of adrenaline, behavioural activity, and heart rate did not change consistently across repetition of exposures. Interestingly, therefore, hormones of the pituitary adrenocortical axis showed a process of adaptation whereas subjects did not adapt to the stressor with respect to titres of adrenaline, heart rate, and particular behaviours (e.g., grid pressing, vocalisation, locomotion). Instead, they continued to react actively towards the social separation. Our results suggest that different stress systems can differ in temporal pattern of their response towards a repeated stressor. Such temporal differences should be considered when studying the effects of repeated stress.

Relationship of plasma epinephrine and circulating eosinophils to nocturnal asthma

The mechanisms of nighttime airway obstruction are not fully established, but include circadian fluctuations in epinephrine and cortisol. To evaluate the relationship of circadian patterns in epinephrine and cortisol to nighttime airflow obstruction, 10 young adult asthma patients (ages 19 to 25 yr) were admitted to a hospital clinical research unit for a 3-day study during which plasma concentrations of epinephrine, cortisol, and histamine were determined along with white blood cell and eosinophil counts every 6 h (1600, 2200, 0400, and 1000 h). Six of the 10 patients experienced at least one episode of nocturnal asthma (defined by more than a 15% decrease in antemeridian (A.M.) to postmeridian (P.M.) FEV1 values). Plasma epinephrine levels (pg/ml) showed a circadian pattern, and the concentration at 2200 h was significantly (p = 0.039) different for the nocturnal and non-nocturnal asthma groups. Circulating eosinophil numbers were greater in subjects who had more frequent episodes of nocturnal asthma, and correlated with the frequency of nocturnal asthma (r = 0.732, p = 0.02, Spearman rank correlation) and average percent decrease in FEV1 (r = 0.667, p = 0.035). Plasma cortisol concentrations also showed circadian patterns, but no direct association with nocturnal asthma; plasma histamine concentrations showed no circadian patterns and no association with nocturnal asthma. Our findings indicate that changes in plasma epinephrine precede the development of nocturnal airway obstruction and contribute to the likelihood of nighttime airflow obstruction.

Characteristics of peripheral blood eosinophils in patients with nocturnal asthma

A number of mechanisms have been proposed to explain nocturnal exacerbations of asthma including circadian patterns in circulating cortisol and catecholamines. These factors may influence airway smooth muscle tone and circulating eosinophil characteristics and function. Because recent evidence has indicated that eosinophils contribute to airway inflammation and the severity of asthma, we evaluated the relationship among peripheral blood eosinophils, their density distribution, and the appearance of nocturnal asthma. Fifteen patients with asthma were evaluated. Spirometry (FEV1 and FVC) was determined at 0400 and 1600, and the number and density distribution of peripheral blood eosinophils were determined. Five patients had nocturnal asthma, defined as a 15% or greater fall in FEV1 at 0400 versus 1600. The patients with nocturnal asthma had greater numbers of eosinophils (cells x 10(6)/ml) at 0400 (0.845 +/- 0.13 versus 0.351 +/- 0.03) and 1600 (0.651 +/- 0.18 versus 0.319 +/- 0.07) and a greater circadian variation with peak eosinophilia at 0400. Furthermore, we found a significant circadian increase in low-density eosinophils (as determined by Percoll density gradient centrifugation) at 0400, but only in patients with nocturnal asthma. These observations suggest that a circadian variation in low density eosinophils may contribute to nocturnal exacerbations of asthma.