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ABSTRACT: Domestic laying hens rely primarily on their hindlimbs for terrestrial locomotion. Although they perform flapping flight, they appear to use maximal power during descent and thus may lack control for maneuvering and avoiding injuries on landing. This in turn may result in injury in open rearing systems. Wing-assisted incline running (WAIR) requires a bird to use its wings to assist the hindlimbs during climbing of an incline, and training in WAIR may therefore provide a useful method to increase a hen's power reserve and control for flight. We subjected hens to an exercise regimen involving inclines to induce WAIR for 16 wk during rearing. We then measured wing and body kinematics during aerial descent from a 155 cm platform. We hypothesized that birds reared with exercise would be better able to modulate their wing and body kinematics for making slower, more-controlled descent and landing. Brown-feathered birds exhibited greater wing beat frequencies than white-feathered birds, which is consistent with the higher wing loading of brown-feathered birds and WAIR-trained birds exhibited greater initial flight velocities compared to control birds. This may indicate that WAIR training provided an improved capacity to modulate flight velocity and strengthen the leg muscles. Providing incline exercises during rearing may therefore improve welfare for adult laying hens as greater initial flight velocity should reduce the power required for supporting body weight in the air and allow a hen to direct her excess power toward maneuvering.

Domestic chickens may live in environments which restrict wing muscle usage. Notably, reduced wing activity and accompanying muscle weakness are hypothesized risk factors for keel bone fractures and deviations. We used radio-frequency identification (RFID) to measure duration spent at elevated resources (feeders, nest-boxes), ultrasonography to measure muscle thickness (breast and lower leg) changes, radiography and palpation to determine fractures and deviations, respectively, following no, partial (one-sided wing sling) and full (cage) immobilization in white- and brown-feathered birds. We hypothesized partially immobilized hens would reduce elevated resource usage and that both immobilization groups would show decreased pectoralis thickness (disuse) and increased prevalence of fractures and deviations. Elevated nest-box usage was 42% lower following five weeks of partial immobilization for brown-feathered hens but no change in resource usage in white-feathered birds was observed. Fully immobilized, white-feathered hens showed a 17% reduction in pectoralis thickness, while the brown-feathered counterparts showed no change. Lastly, fractures and deviations were not affected in either strain or form of wing immobilization; however, overall low numbers of birds presented with these issues. Altogether, this study shows a profound difference between white- and brown-feathered hens in response to wing immobilization and associated muscle physiology.

ABSTRACT: The impact of varying light intensities on layer pullets is not yet well understood. Behaviorally, brighter illumination may increase pullet activity levels by allowing better navigation in the complexity of non-cage systems. In addition, light intensity was previously demonstrated to affect the levels of calcium and phosphate regulating hormones in mice. The objective of this study was to examine how exposure of pullets to different light intensity affects their calcium and phosphorus homeostasis. Lohmann LSL-Lite and Lohmann Brown-Lite pullets were randomized into 4 individually controlled rooms with 6 pens per room, which were assigned to 10 or 50 lux light intensity supplied via white LED lighting during the photophase. After 8 and 16 wk of exposure, plasma calcium, phosphorus, and magnesium were measured by inductively coupled plasma optical emission spectrometry; and parathyroid hormone, 1,25-dihydroxyvitamin D, fibroblast growth factor 23, and markers of bone formation and resorption were measured by ELISA. Intestine and kidney samples were collected at 16 wk and gene expression of receptors for calcium and phosphate regulating hormones was assessed. The data were analyzed by one-way ANOVA. Lohmann Brown-Lite pullets exposed to 50 lux for 8 wk exhibited lower ionized Ca levels and a trend for increased bone formation markers compared to pullets reared in 10 lux. Thus, higher light intensity during rearing may beneficially affect calcium homeostasis and bone formation in young Lohmann Brown-Lite chicken.

Effects of rearing cage type and dietary limestone particle size (LPS) on growth, apparent retention (AR) of nutrients, and bone quality were investigated. The treatments were arranged in a 2 × 3 factorial with cage (conventional, CON and furnished, FUR) and LPS (fine, < 0.595 mm, F; medium, 0.595 to < 1.68 mm, M; and 1:1 mixture of F and M wt/wt; FM). A total of 900-day-old Lohmann LSL-Lite chicks were placed in CON (20 chicks/cage) and FUR (30 chicks/cage) based on BW. The diets were formulated according to breeder's nutrient specifications for starter, grower, and developer phases. At the end of 4, 12, and 16 wk of age (woa), 2 pullets/cage were euthanized for samples. At 12 and 16 woa, 1 pullet/cage was transferred to metabolism cages for AR measurements. There was no interaction (P > 0.05) between cage type and LPS on response variables. At 4 woa, body (P = 0.002) and bone (P < 0.05) weight was higher for CON than FUR pullets, but this was reversed (P

Emerging market differentiation for broiler meat from strains exhibiting a range of growth rates is necessitating comparative research on various physiological and production aspects of these strains. The objective of the present study was to compare select gastrointestinal, tibial, and plasma attributes in a sample of 48-day-old (50 male and 50 female) broilers obtained from fast-and slow-growing flocks maintained under similar feed and management regimens. Eight birds were randomly selected from a fast (B; representative of modern commercial strains) and each of the 4 slow-growing strains (SG; D, H, M, and E). The strains differed by estimated time to reach 2.2 kg bodyweight corresponding to 36, 50, 42, 44, and 50 D for B, D, H, M, and E, respectively. Blood samples were collected to determine plasma metabolites, and birds were subsequently euthanized, weighed, and necropsied for gizzard and small intestine weight, jejunal tissue for histomorphology, ceca digesta samples for concentration of short-chain fatty acids (SCFA) and left tibia for ash content. Gizzard was heavier (P 0.05) strain differences on SCFA, jejunal villus height and crypt depth, plasma proteins, and electrolytes. Strains D, H, and M exhibited higher (P = 0.01) tibia ash concentration than B; E was intermediate and not different (P > 0.05) from any strain. Specifically, the tibia ash for B, D, H, SG 3, and E were 1.24, 1.44, 1.43, 1.49, and 1.39 g/kg BW, respectively. The B birds showed higher (P

Feather loss in domestic chickens can occur due to wear and tear, disease or bird-to-bird pecking. Flight feather loss may decrease wing use, cause pectoral muscle loss and adversely impact the keel bone to which these muscles anchor. Feather loss and muscle weakness are hypothesized risk factors for keel bone fractures that are reported in up to 98% of chickens. We used ultrasound to measure changes in pectoral muscle thickness and X-rays to assess keel bone fracture prevalence following symmetric clipping of primary and secondary feathers in white- and brown-feathered birds. Four and six weeks after flight feather clipping, pectoralis thickness decreased by approximately 5%, while lower leg thickness increased by approximately 5% in white-feathered birds. This pectoralis thickness decrease may reflect wing disuse followed by muscle atrophy, while the increased leg thickness may reflect increased bipedal locomotion. The lack of effect on muscle thickness in brown-feathered hens was probably due to their decreased tendency for aerial locomotion. Finally, pectoralis thickness was not associated with keel bone fractures in either white- or brown-feathered birds. This suggests that the white-feathered strain was more sensitive to feather loss. Future prevention strategies should focus on birds most susceptible to muscle loss associated with flight feather damage.

Ground-dwelling species of birds, such as domestic chickens (Gallus gallus domesticus), experience difficulties sustaining flight due to high wing loading. This limited flight ability may be exacerbated by loss of flight feathers that is prevalent among egg-laying chickens. Despite this, chickens housed in aviary style systems need to use flight to access essential resources stacked in vertical tiers. To understand the impact of flight feather loss on chickens' ability to access elevated resources, we clipped primary and secondary flight feathers for two hen strains (brown-feathered and white-feathered, n = 120), and recorded the time hens spent at elevated resources (feeders, nest-boxes). Results showed that flight feather clipping significantly reduced the percentage of time that hens spent at elevated resources compared to ground resources. When clipping both primary and secondary flight feathers, all hens exhibited greater than or equal to 38% reduction in time spent at elevated resources. When clipping only primary flight feathers, brown-feathered hens saw a greater than 50% reduction in time spent at elevated nest-boxes. Additionally, brown-feathered hens scarcely used the elevated feeder regardless of treatment. Clipping of flight feathers altered the amount of time hens spent at elevated resources, highlighting that distribution and accessibility of resources is an important consideration in commercial housing.

Abstract Background There is a critical need to develop appropriate on-farm euthanasia methods for poultry species. Euthanasia methods should affect the brain first causing insensibility, followed by cardiorespiratory arrest. Neck or cervical dislocation methods, either manual (CD) or mechanical (MCD), are reported to cause a prolonged time to loss of sensibility and death with inconsistent results upon application, especially MCD methods. However, there is limited information on cervical dislocation in turkeys. The overall objective of this study was to assess the welfare implications of CD and a newly developed MCD device for euthanasia of cull turkeys in comparison with intravenous (IV) pentobarbital sodium (1 mL/4.5 kg), the gold standard euthanasia method. Time to death using electroencephalographic (EEG) and behavioural responses were monitored in eight and eighteen week-old turkeys for five minutes after each euthanasia method application. Spectral analyses of EEG responses and onset of isoelectric EEGs were compared to baseline EEG recordings of birds under anesthesia and behavioural responses were studied among euthanasia treatments. A significant decrease in brain activity frequencies analysis and isoelectric EEG were recorded as time of brain death. Results All turkeys euthanized with IV pentobarbital sodium presented a rapid and irreversible decrease in the EEG activity at approximately 30s post-injection with minimal behavioural responses. CD and MCD methods caused EEG responses consistent with brain death at approximately 120 s and 300 s, respectively. Additionally, isoelectric EEGs resulted in all pentobarbital sodium and CD groups, but only in 54 and 88% of the eight and eighteen week-old turkeys in the MCD groups, respectively. There were few clear patterns of behavioural responses after CD and MCD application. However, cessation of body movement and time to isoelectric EEG after CD application were positively correlated. Conclusions Use of CD and MCD resulted in a prolonged time to death in both age groups of turkeys. MCD application presents a number of welfare risks based on electroencephalographic and behavioural findings. Intravenous pentobarbital sodium induced rapid brain death, but possesses several on-farm limitations. To develop improvements in cervical dislocation methods, further investigations into combined or alternative methods are required to reduce the prolonged time to insensibility and death.

The effects of light intensity (L) are not well studied in pullets. Our research objective was to study the effect of L on navigational success, behavior, and welfare of two pullet strains (S). In two repeated trials, a 3 × 2 × 4 factorial arrangement tested three L (10, 30, 50 lux) and two S (Lohmann Brown-Lite (LB), LSL-Lite (LW)) at four ages. One thousand eight hundred pullets/S (0–16 wk) were randomly assigned to floor pens within light-tight rooms (three pens/S/room, four rooms/L) containing four parallel perches and a ramp. Data collection included jumping frequency and success (24h continuous sampling), novel object tests (fear), heterophil to lymphocyte (H/L) ratios (stress), and behavior (instantaneous scan sampling) during photoperiods. L did not affect injurious behavior, fear, or H/L. Pullets reared at 50 lux spent more time preening than at 10 lux. Pullets reared at 10 lux spent more time wall pecking than at 50 lux. Time spent standing and preening and total number and accuracy of jumping increased with age. Pullets reared at 30 lux had higher jumping frequency than at 10 lux; accuracy was not affected. LW jumped more than LB, but with similar success. LB spent more time exploring and scored higher in the fear and stress assessments, suggesting S differences.

This study investigated changes in the electroencephalograph (EEG) power spectrum as well as physiological and behavioral responses to on-farm killing via mechanical cervical dislocation (MCD), manual cervical dislocation (CD) or intravenous pentobarbital sodium administration in lightly anesthetized laying hens, to evaluate the welfare impact of each method. A mixed group of 44 white Leghorn and Smoky Joe laying hens (60 weeks-old) were anesthetized with isoflurane in oxygen and maintained at 1.5–2% isoflurane/O2 until the killing method was applied. Birds were randomly assigned to one of three experimental groups on each trial day. The EEG was recorded bilaterally in a four-electrode montage. After recording a 5-min baseline, the killing method was applied and EEGs and other behavioral and physiological responses, including convulsions, gasping, cessation of body movements and feather erection were recorded for 5 min. Changes in EEG frequency bands (alpha, beta, delta, theta), median frequency (F50), 95% spectral edge frequency (F95), and total power (Ptot) were used to assess the quality of the on-farm killing event. Within 15 s after administration of pentobarbital sodium, there were significant decreases in mean frequency bands, increases in mean F50 and F95, and decreases in Ptot, suggesting brain death. In addition, birds presented a shorter latency to cessation of movement after pentobarbital sodium injection compared to MCD and CD (22 vs. 115 s and 136 s, respectively). There were significant increases in F95 and decreases in Ptot at 120 s after application of CD; and a concomitant decrease in the frequency bands at 135 s and isoelectric EEG at 171 ± 15 s. Changes consistent with brain death after MCD included isoelectric EEG at 207 ± 23 s and a significant decreases in some frequency bands at 300 s post-application. No other significant spectrum frequency changes were observed in the MCD group, suggesting brain death likely occurred near the 5-min endpoint. There was no clear association between behavioral, physiological, and EEG responses within CD and MCD treatments. The data demonstrate that pentobarbital sodium induced a rapid death with minimal behavioral and physiological responses regardless of strain of hens. In comparison, use of CD and MCD resulted in a slow onset of brain death in hens.

A total of 2,145 pigs were transported for 8 h in summer (six trips) and winter (five trips) using a pot-belly trailer accommodating pigs in four locations (upper deck or UD, bottom-nose or BN, middle deck or MD and bottom deck or BD). Heart rate of pigs during loading and transportation and lactate and creatine kinase (CK) concentrations in exsanguination blood were measured. Meat quality was evaluated in the Longissimus thoracis (LT), Semimembranosus (SM) and Adductor (AD) muscles. During summer, pigs loaded in the UD and MD had higher (P < 0.05) heart rate at loading compared to those located in the BD and BN. Blood lactate and CK concentrations were higher (P < 0.001) in winter than in summer. Lactate concentration was higher (P = 0.01) in the blood of pigs transported in the BN. Pigs transported in the BN had higher pHu values in the LT, SM and AD muscles (P = 0.02, P < 0.001 and P = 0.002, respectively) and lower (P = 0.002) drip loss values in the SM muscle. This study confirms that some locations within the PB trailer have a negative impact on the welfare of pigs at loading and during transport with more pronounced effects in the winter due to the additive effect of cold stress.

The authors would like to add that “Sébastien Goumon was supported by Grant No MZERO0716 from the Czech Ministry of Agriculture” in the Acknowledgement Section of their paper published in Animals [...]

The objective of this study was to assess the effects of the season, travel duration and trailer compartment location on blood creatine-kinase (CK), lactate and cortisol concentrations in 384 pigs and assess their relationships with trailer temperature, heart rate and gastrointestinal tract temperature (GTT), behavior, carcass damage scores and meat quality. Blood CK was greater in pigs transported in summer (p = 0.02), after 18 h transportation (p < 0.001) and in pigs located in C4, C5 and C10 (p = 0.002). In winter, the concentration of blood lactate was higher (p = 0.04) in pigs transported for 6 h in C5. Pigs located in C10 showed higher (p = 0.01) concentration of cortisol than those transported for 18h in C4 in summer. The highest correlations were between blood cortisol and GTT (r = 0.53; p < 0.001), and between blood CK and GTT (r = 0.41; p < 0.001), truck temperature (r = 0.42; p < 0.001), and pHu in the longissimus muscle (r = 0.41; p < 0.001). In conclusion, although increased blood cortisol and CK levels appear to indicate a physical stress condition in transported pigs, the weak to moderate correlations with environmental and other animal welfare indicators suggest that blood stress parameters can only be used as a complementary measurement in the assessment of the pigs’ response to transport stress.