Providing elevated structures in the pullet rearing environment affects behavior during initial acclimation to a layer aviary.

Spatial abilities of hens are particularly sensitive to development during early life. Experiences in pullet housing may have lasting consequences on adult hens' movements in cage-free environments. We tested whether opportunities to access elevated spaces during rearing improved hens' use of a multitiered aviary. Female Dekalb White pullets were reared in either floor pens (FL), single-tiered aviaries (ST), or 2-tiered aviaries (TT; n = 5 pens/environment) through 16 wk of age. Rearing structures were replaced with identical multitiered aviaries at 17 wk. The distribution of the flock within the aviary and the vertical transitions of 10 focal hens/pen across the aviary were determined from videos recorded during their first (D1) and seventh (D7) day of aviary access, as well as at 19, 23, and 27 wk of age. Prevalence of floor eggs was recorded weekly from 17 to 28 wk of age. On D1, more ST and TT hens utilized the aviary during the daytime (P = 0.0077), made more vertical transitions when searching for a roosting spot in the evening (P = 0.0021), and maintained a consistent distance traveled during transitions compared to FL hens (P = 0.02). These differences disappeared by D7, except that ST and TT hens continued to roost on the highest perches of the aviary more (P < 0.0001) than FL hens through 27 wk of age. FL hens laid more floor eggs than ST and TT hens for the first 2 wk of lay (P < 0.0001). The majority (97.9%) of vertical transitions was controlled. Uncontrolled transitions were highest at D1 and decreased by D7 (P = 0.0009) and were not affected by rearing (P = 0.33). The results suggest that hens reared with minimal height are hesitant to use the laying hen aviaries when they are first transferred. They acclimate within 1 to 2 wk, but continue to roost less in the highest accessible level.

The effect of expressive writing on wound healing: Immunohistochemistry analysis of skin tissue two weeks after punch biopsy wounding.

OBJECTIVE: To investigate the effects of expressive writing and its timing (pre or post wounding) on re-epithelialisation and leucocyte subsets within healing tissue. We previously showed expressive writing pre-wounding improved re-epithelialisation. Here we investigate cellular processes in the wound. METHODS: In a 2(writing content) x 2(writing timing) randomized trial, 122 participants were randomized to perform either expressive or control writing, before or after a 4 mm punch biopsy wound. On day 14 post-wounding, participants had a 5 mm punch biopsy of the initial wound. Seven of 16 primary registered outcomes were analysed, including re-epithelialisation from two photographs of the 4 mm biopsy (previously reported). This paper reports immunohistochemistry analysis of five primary outcomes - Langerhans cells, immune cell activation (HLA and CD3+), and macrophages (CD68 and MPO) - in the 5 mm biopsies in a random sample of 96 participants. RESULTS: Participants who performed either writing task pre-wounding had greater Langerhans cell infiltration, than those who wrote post-wounding (F(1,85) = 7.86, p = .006, ηp2 = 0.08). Those who performed expressive writing also had greater Langerhans cell infiltration than those who performed control writing (F(1,85) = 4.00, p = .049, ηp2 = 0.04). There were no significant group or interaction effects on immune cell activation or macrophages. Healed wounds on day 10 had lower levels of macrophages (z = -1.96, p = .050), and CD3+ cells (z = -1.99, p = .046) than non-healed wounds. CONCLUSION: Langerhans cells in the healing skin are affected by the timing and topic of writing. More research is needed to further explore timing and corroborate these results. CLINICAL TRIALS REGISTRATION: Registered at https://www.anzctr.org.au/ (Trial ID: ACTRN12614000971639).

Rearing experience with ramps improves specific learning and behaviour and welfare on a commercial laying farm.

To access resources in commercial laying houses hens must move between levels with agility to avoid injury. This study considered whether providing ramps during rear improved the ability of birds to transition between levels. Twelve commercial flocks (2000 birds/flock) on a multi-age site were examined between 1 and 40 weeks of age. All birds had access to elevated perching structures from 4 days of age. Six treatment flocks were also provided with ramps during rear to facilitate access to these structures. Flocks were visited three times during rear and three times at lay to record transitioning behaviour and use of the elevated structures, together with scores for keel bone and feather damage. Ramp reared flocks used the elevated structures to a greater extent at rear (P = 0.001) and at lay, when all flocks had ramps, showed less hesitancy [i.e. pacing (P = 0.002), crouching (P = 0.001) and wing-flapping (P = 0.001)] in accessing levels. Mean levels of keel bone damage were reduced in ramp reared flocks (52%) compared with control flocks (64.8%) at 40 weeks of age (P = 0.028). The early life experience of the ramp reared flocks enabled specific learning that translated and persisted in later life and resulted in overall welfare benefits.

Stiffness-matched biomaterial implants for cell delivery: clinical, intraoperative ultrasound elastography provides a 'target' stiffness for hydrogel synthesis in spinal cord injury.

Safe hydrogel delivery requires stiffness-matching with host tissues to avoid iatrogenic damage and reduce inflammatory reactions. Hydrogel-encapsulated cell delivery is a promising combinatorial approach to spinal cord injury therapy, but a lack of in vivo clinical spinal cord injury stiffness measurements is a barrier to their use in clinics. We demonstrate that ultrasound elastography - a non-invasive, clinically established tool - can be used to measure spinal cord stiffness intraoperatively in canines with spontaneous spinal cord injury. In line with recent experimental reports, our data show that injured spinal cord has lower stiffness than uninjured cord. We show that the stiffness of hydrogels encapsulating a clinically relevant transplant population (olfactory ensheathing cells) can also be measured by ultrasound elastography, enabling synthesis of hydrogels with comparable stiffness to canine spinal cord injury. We therefore demonstrate proof-of-principle of a novel approach to stiffness-matching hydrogel-olfactory ensheathing cell implants to 'real-life' spinal cord injury values; an approach applicable to multiple biomaterial implants for regenerative therapies.

Welfare Challenges of Dairy Cows in India Identified Through On-Farm Observations.

India has the largest population of dairy cattle in the world at over 48 million animals, yet there has been little formal assessment of their welfare reported. Through observations of dairy cows on 38 farms in Kerala, India, we aimed to investigate the welfare of these animals and the practicality of animal-based assessments within common farming systems. Substantial welfare challenges were identified. All cows were close-tied (less than 1 m length) via a halter that pierced the nasal septum when housed, which was for the entire day (50% of farms) or part thereof. When outside access was available, it was also usually restricted by close-tying, longline tether, or hobbling. Ad libitum water was only available on 22% of farms and food access was also restricted (mean of 4.3 h/day). Future work should focus on encouraging dairy farmers in India to improve the welfare of their dairy cattle by: ceasing to tie and tether cattle (or at least providing tied and tethered cattle with exercise opportunities); providing unlimited access to drinking water and a readier supply of food (especially quality green forage/fodder); cleaning housing more frequently; providing strategies to prevent heat stress; breeding cattle suited to environmental conditions and with increased resistance to heat stress; and carrying out welfare assessments more regularly using a validated protocol and rectifying the causes of poor welfare. Such changes could substantially improve the welfare of tens of millions of cattle.

Modeling collisions in laying hens as a tool to identify causative factors for keel bone fractures and means to reduce their occurrence and severity.

Keel fractures represent a major productivity and welfare issue for the laying hen industry with greater than 50% of birds in recent surveys across various commercial operations and nations exhibiting some form of damage by end of lay. While the causes are likely multifactorial and influenced by age, diet, genetic line, and other factors, high energy collisions with house furnishings and conspecifics in the barn are believed to be a major contribution to the frequency and severity of factures. The current study applies a previously described ex vivo impact testing protocol to quantify susceptibility to keel bone damage across an extensive range of collision energies and ages. We also link fracture susceptibility with bone and physiological measures likely to influence skeletal resilience. Further, we applied the impact testing protocol to evaluate the benefit of an omega-3 enriched diet to improve bone health and reduce fracture susceptibility. Our results indicated that fracture susceptibility increased rapidly from 23 weeks of age, peaking at 49.5 weeks of age and thereafter decreasing. Fracture susceptibility also varied with multiple natural characteristics of bone, including mineral density, though the nature of that relationship was dependent on whether an old fracture was present. Severity of the experimental fracture demonstrated considerable variation with collision energy and biomechanical properties. An omega-3 enhanced diet provided a protective effect against fractures, though only in terms of collision energies that were relatively low. In conclusion, the impact testing protocol provided a unique means to assess fracture susceptibility and quantify the role of likely influencing bird-level biological factors, both those that vary naturally as well as when altered through specific interventions.

Behavioural and physiological responses of laying hens to automated monitoring equipment.

Automated monitoring of behaviour can offer a wealth of information in circumstances where observing behaviour is difficult or time consuming. However, this often requires attaching monitoring devices to the animal which can alter behaviour, potentially invalidating any data collected. Birds often show increased preening and energy expenditure when wearing devices and, especially in laying hens, there is a risk that individuals wearing devices will attract aggression from conspecifics. We studied the behavioural and physiological response of 20 laying hens to backpacks containing monitoring devices fastened with elastic loops around the wing base. We hypothesised that backpacks would lead to a stress-induced decrease in peripheral temperature, increased preening, more aggression from conspecifics, and reduced bodyweights. This was evaluated by thermography of the eye and comb (when isolated after fitting backpacks), direct observations of behaviour (when isolated, when placed back into the group, and on later days), and weighing (before and after each 7-day experimental period). Each hen wore a backpack during one of the two experimental periods only and was used as her own control. Contrary to our hypothesis, eye temperature was higher when hens wore a backpack (No backpack: 30.2 °C (IQR: 29.0-30.6) vs. Backpack: 30.9 °C (IQR: 30.0-32.0), P < 0.001). Eye temperature of hens wearing a backpack was strongly correlated to the time spent preening (rs = 0.8, P < 0.001), suggesting that the higher temperatures may have been due to preening itself, or to a low head position or decreased heat dissipation when preening under the wings. Aggressive behaviour was very rare and no effect of the backpacks was found. In line with our hypothesis, backpacks increased preening on the day of fitting, both when isolated (No backpack: 0% (IQR: 0-1) vs. Backpack: 22% (IQR: 1-43), P < 0.01) and when back in the group (No backpack: 0% (IQR: 0-27) vs. Backpack: 43% (IQR: 5-77), P < 0.001). However, no effect on preening was observed 2-7 days afterwards. Other behavioural changes suggested that on the day of fitting hens prioritized attempts to (re)move the backpack and were less attentive to their surroundings. However, only equipment pecking (i.e., pecking the backpack or leg rings) was still affected 2-7 days after fitting (No backpack: 0 pecks/hen/minute (IQR: 0-0), vs. Backpack: 0 (IQR: 0-0.07), P < 0.05). We found no effect of our backpacks on bodyweight. In conclusion, our backpacks seem suitable to attach monitoring equipment to hens with only a very minor effect on their behaviour after a short acclimation period (≤2 days).

Mechanical properties of 6 finger-trap suture techniques.

OBJECTIVE: To identify the most common methods used by surgeons to place finger-trap sutures (FTS), and determine their influence on the biomechanical properties of constructs. STUDY DESIGN: Questionnaire and experimental study. METHODS: Six commonly used FTS methods (A-F) were identified from literature review and questionnaire. Constructs made with 3-metric nylon suture and 18-French polyurethane esophagostomy tubing were tested in axial loading to failure. Two patterns (B and D) selected based on common use and biomechanical performance were further tested, with 2, 4, and 8 repeats along the tube. Displacement, load, and energy at failure were compared between constructs, and failure mode was video recorded. RESULTS: Patterns E and F were susceptible to slipping (P < .001). Patterns A and D were stiffer than pattern E, and patterns A-D were stiffer than pattern F (P = .012). Patterns A and B had less extension than pattern E and F, and patterns A-D had less extension than pattern F (P = .002). 87.5% of FTS failed by breaking at the first suture knot. The number of repeats had no effect on FTS performance, but catastrophic failure occurred in 2 constructs with 2 repeats. CONCLUSION: The mechanical behavior of suture-tube constructs and failure mode is affected by the FTS pattern. Patterns E and F are not advocated due to suture slippage. The number of repeats may not affect the FTS performance, but a minimum of 4 repeats is recommended. Overall, patterns B, C, and D performed the best in axial loading.

Biomechanical evaluation of simulated feline patellar fracture repairs.

OBJECTIVE: To investigate four techniques for stabilization of feline patellar fracture. METHODS: Feline cadaveric stifles with simulated patellar fracture were stabilized with one of four techniques: Group A - circumferential wire, group B - figure-of-eight wire, group C - combined figure-of-eight and circumferential wire, group D - pin and tension band wire. All repairs were subjected to a period of cyclic loading prior to load to failure testing. Experiments were recorded by video capture to determine load at failure and failure mode. Failure was defined as an opening of the fracture gap of 3 mm. RESULTS: Mean fracture gap opening (±SD) during peak loading after 1000 cycles was: group A with 1.66 mm (± 0.69), group B with 1.01 mm (± 0.45), group C with 0.81 mm (± 0.58), and group D with 0.65 mm (± 0.54). Groups C and D had significantly lower mean fracture gap opening after 1000 cycles when compared to group A (p <0.05). Mean loads (± SD) at failure were: group A with 171.4 N (± 62.2), group B with 208.7 N (± 20.7), group C with 288.2 N (± 62.5), and group D with 219.5 N (± 48.0). Group C had significantly higher mean load to failure than all other groups (p <0.05). There was no difference between other groups. In groups A, B and C the principle mode of failure was wire elongation and tearing of sutures through the retinaculae and periarticular soft tissues. In group D, the principle mode of failure was the pin pulling through the bone of the distal fragment. CONCLUSIONS: Combined figure-of-eight and circumferential wires may be useful for treatment of transverse feline patellar fracture.

Tensile Comparison of Polydioxanone, Polyglyconate, and Barbed Glycolide-Trimethylene Carbonate Suture in Canine Cadaveric Tensor Fascia Lata.

OBJECTIVE: To compare the mode of failure, load at yield, ultimate load to failure and stiffness of non-barbed polydioxanone, non-barbed polyglyconate and barbed glycolide-trimethylene carbonate (GTC) suture in canine cadaveric fascia. STUDY DESIGN: Ex vivo biomechanical study. SAMPLE POPULATION: 18 fascia lata specimens from 9 canine cadavers. METHODS: 6 fascia lata specimens were sutured with polydioxanone, 6 with polyglyconate, and 6 with barbed GTC suture. Load at yield, stiffness, ultimate load to failure were measured using tensile strength testing. Statistical analysis was used to compare outcomes between suture materials. The mode of failure was recorded and described. RESULTS: The load at yield and ultimate load to failure were significantly greater for polydioxanone than barbed GTC (P=.045 and P=.016, respectively). The load at yield and ultimate load to failure was not significantly different between polydioxanone and polyglyconate (P=.687 and P=.586, respectively). The load at yield and the ultimate load to failure was not significantly different between polyglyconate and barbed GTC (P=.194 and P=.109, respectively). Stiffness was not different between constructs (P=.103). Polydioxanone and polyglyconate failed by suture breakage and suture pullout. Barbed GTC failed by suture slippage and suture breakage. CONCLUSION: Our results showed that under the conditions of this study, 4-0 monofilament polydioxanone had a greater load at yield and load to failure than similarly sized, barbed copolymer suture in the fascia lata. This finding may help direct suture choice for fascial closure.

Illness Beliefs Predict Mortality in Patients with Diabetic Foot Ulcers.

BACKGROUND: Patients' illness beliefs have been associated with glycaemic control in diabetes and survival in other conditions. OBJECTIVE: We examined whether illness beliefs independently predicted survival in patients with diabetes and foot ulceration. METHODS: Patients (n=169) were recruited between 2002 and 2007. Data on illness beliefs were collected at baseline. Data on survival were extracted on 1st November 2011. Number of days survived reflected the number of days from date of recruitment to 1st November 2011. RESULTS: Cox regressions examined the predictors of time to death and identified ischemia and identity beliefs (beliefs regarding symptoms associated with foot ulceration) as significant predictors of time to death. CONCLUSIONS: Our data indicate that illness beliefs have a significant independent effect on survival in patients with diabetes and foot ulceration. These findings suggest that illness beliefs could improve our understanding of mortality risk in this patient group and could also be the basis for future therapeutic interventions to improve survival.

Stress-related changes to immune cells in the skin prior to wounding may impair subsequent healing.

Higher psychological stress is associated with slower dermal wound healing, but the immunological mechanisms behind this effect are only partially understood. This paper aims to investigate whether immune cells present in the skin prior to wounding can affect subsequent healing in high-stress and low-stress participants. Two studies are presented in which skin biopsies were analysed using immunohistochemistry for numbers of macrophages and Langerhans cells, and immune cell activation (Study 2 only). Immune cells were related to perceived stress levels and subsequent healing. Study 1 included 19 healthy older adults and showed that higher stress was associated with significantly fewer macrophages in the skin. Study 2 included 22 younger adults and showed that higher stress was associated with significantly lower activation of immune cells in the skin. Furthermore, lower activation of immune cells (as measured by human leukocyte antigen (HLA expression)) and fewer Langerhans cells were associated with slower healing. Together these studies show the first preliminary evidence that the number and activation of immune cells in the skin prior to wounding are affected by stress and can impact healing. Larger studies are needed to confirm these effects.

Effect of Osteotomy Position and Tibial Plateau Rotation on the Tensile Force Required for Failure of the Canine Quadriceps Mechanism.

OBJECTIVE: To measure the tensile force required for failure of the quadriceps mechanism with different tibial tuberosity widths and different degrees of rotation of the tibial plateau after radial osteotomy of the proximal tibia. STUDY DESIGN: Ex vivo study, randomized unblocked design ANIMALS: Thirty-five hind limbs from 18 adult Greyhound cadavers. METHODS: Part 1 (15 limbs)--The center of rotation of the proximal tibial radial osteotomy was advanced craniodistally, progressively reducing absolute tibial tuberosity width (ATTW) for 5 different widths. Part 2 (21 limbs)-Tibial plateau rotation was performed at a set ATTW. Rotation was varied as a function of tibial tuberosity position with rotation proximal, level with, or distal to the tuberosity. All 35 limbs were tested with force applied via the quadriceps mechanism until construct failure occurred. RESULTS: All but 2 limbs failed by fracture of the tibial tuberosity. The tensile force required for failure of the quadriceps mechanism increased linearly with increasing ATTW. Significantly less force (P = .016) was required for failure of the quadriceps mechanism when the rotation of the tibial plateau was distal to the level of the patella tendon (mean 1,877 N) compared to when it was above the level of the patella tendon (mean 2,533 N). Rotation of the tibial plateau distal to the level of the patella tendon insertion point resulted in fracture at the base of the tibial tuberosity, level with the tibial plateau buttress. CONCLUSION: The overwhelming mode of failure of the quadriceps mechanism was by tibial tuberosity fracture, thus this was the weakest part of the construct. Reducing the tibial tuberosity width and rotation of the tibial plateau segment below the patella tendon insertion decreased the force required for tibial tuberosity fracture. These results support the idea of a safe point with the tibial plateau segment providing buttress to the tibial tuberosity.

Biomechanical comparison of canine fascia lata and thoracolumbar fascia: an in vitro evaluation of replacement tissues for body wall reconstruction.

OBJECTIVES: To compare the suitability of thoracolumbar fascia (TLF) and fascia lata (FL) for body wall defect repair in dogs, by examining their biomechanical properties and useable surface area. STUDY DESIGN: Experimental. ANIMALS: Dogs (n = 8). METHODS: Fresh TLF and FL grafts were obtained, surface area was calculated before testing to failure in 2 different modes: tensile testing and resistance to suture pullout, in 2 perpendicular orientations. RESULTS: Useable TLF surface area was significantly greater than for FL. Maximum load, energy to break, and elastic modulus of FL was significantly greater than that of TLF in tensile testing, but no apparent difference in the ultimate stress or strain was identified. There was no overall difference in suture pullout load between TLF and FL. During tensile testing, tissue orientation had a significant influence on ultimate load, stress, and elastic modulus for both tissue types, with strain and energy to break only having significant effects for TLF and FL, respectively. CONCLUSIONS: The greater tensile strength and stiffness of FL compared to TLF was not reflected in its material properties, implying any difference was a consequence of greater thickness. Suture pullout was not significantly different between the 2 tissues, perhaps limiting the clinical significance of the tissue mechanics. Tissues were anisotropic with respect to mechanical properties, thus orientation may be an important factor.

Illness beliefs predict self-care behaviours in patients with diabetic foot ulcers: a prospective study.

AIMS: Patients' illness beliefs are known to be influential determinants of self-care behaviours in many chronic conditions. In a prospective observational study we examined their role in predicting foot self-care behaviours in patients with diabetic foot ulcers. METHODS: Patients (n=169) were recruited from outpatient podiatry clinics. Clinical and demographic factors, illness beliefs and foot self-care behaviours were assessed as baseline (week 0). Foot self-care behaviours were assessed again 6, 12 and 24 weeks later. Linear regressions examined the contribution of beliefs at baseline to subsequent foot self-care behaviours, controlling for past behaviour (i.e., foot self-care at baseline) and clinical and demographic factors that may affect foot self-care (i.e., age and ulcer size). RESULTS: Our models accounted for between 42 and 58% of the variance in foot self-care behaviours. Even after controlling for past foot-care behaviours, age and ulcer size; patients' beliefs regarding the symptoms associated with ulceration, their understanding of ulceration and their perceived personal control over ulceration emerged as independent determinants of foot self-care. CONCLUSIONS: Patients' beliefs are important determinants of foot-care practices. They may, therefore, also be influential in determining ulcer outcomes. Interventions aimed at modifying illness beliefs may offer a means for promoting self-care and improving ulcer outcomes.

Subchondral bone plate thickening precedes chondrocyte apoptosis and cartilage degradation in spontaneous animal models of osteoarthritis.

Osteoarthritis (OA) is the most common joint disorder characterised by bone remodelling and cartilage degradation and associated with chondrocyte apoptosis. These processes were investigated at 10, 16, 24, and 30 weeks in Dunkin Hartley (DH) and Bristol Strain 2 (BS2) guinea pigs that develop OA spontaneously. Both strains had a more pronounced chondrocyte apoptosis, cartilage degradation, and subchondral bone changes in the medial than the lateral side of the tibia, and between strains, the changes were always greater and faster in DH than BS2. In the medial side, a significant increase of chondrocyte apoptosis and cartilage degradation was observed in DH between 24 and 30 weeks of age preceded by a progressive thickening and stiffening of subchondral bone plate (Sbp). The Sbp thickness consistently increased over the 30-week study period but the bone mineral density (BMD) of the Sbp gradually decreased after 16 weeks. The absence of these changes in the medial side of BS2 may indicate that the Sbp of DH was undergoing remodelling. Chondrocyte apoptosis was largely confined to the deep zone of articular cartilage and correlated with thickness of the subchondral bone plate suggesting that cartilage degradation and chondrocyte apoptosis may be a consequence of continuous bone remodelling during the development of OA in these animal models of OA.

Increased chondrocyte apoptosis is associated with progression of osteoarthritis in spontaneous Guinea pig models of the disease.

Osteoarthritis (OA) is the most common joint disease characterised by degradation of articular cartilage and bone remodelling. For almost a decade chondrocyte apoptosis has been investigated as a possible mechanism of cartilage damage in OA, but its precise role in initiation and/or progression of OA remains to the determined. The aim of this study is to determine the role of chondrocyte apoptosis in spontaneous animal models of OA. Right tibias from six male Dunkin Hartley (DH) and Bristol Strain 2 (BS2) guinea pigs were collected at 10, 16, 24 and 30 weeks of age. Fresh-frozen sections of tibial epiphysis were microscopically scored for OA, and immunostained with caspase-3 and TUNEL for apoptotic chondrocytes. The DH strain had more pronounced cartilage damage than BS2, especially at 30 weeks. At this time point, the apoptotic chondrocytes were largely confined to the deep zone of articular cartilage (AC) with a greater percentage in the medial side of DH than BS2 (DH: 5.7%, 95% CI: 4.2-7.2), BS2: 4.8%, 95% CI: 3.8-5.8), p > 0.05). DH had a significant progression of chondrocyte death between 24 to 30 weeks during which time significant changes were observed in AC fibrillation, proteoglycan depletion and overall microscopic OA score. A strong correlation (p ≤ 0.01) was found between chondrocyte apoptosis and AC fibrillation (r = 0.3), cellularity (r = 0.4) and overall microscopic OA scores (r = 0.4). Overall, the rate of progression in OA and apoptosis over the study period was greater in the DH (versus BS2) and the medial AC (versus lateral). Chondrocyte apoptosis was higher at the later stage of OA development when the cartilage matrix was hypocellular and highly fibrillated, suggesting that chondrocyte apoptosis is a late event in OA.