Productivity and mortality of laying hens in aviaries: a systematic review

A systematic review of investigations on productivity, mortality and cannibalism of laying hens housed in aviaries is presented. In Part One we reviewed the studies that compared these parameters between laying hens housed in aviaries and in conventional cages. In Part Two we investigated the relative impact of strain, beak trimming and rearing condition on productivity and mortality in aviaries. The comparative analysis revealed that aviary hens consumed 3.0 % more food than caged hens, and food conversion was 6.7 % higher in aviaries than in cages. On the other hand, the mortality rate and cannibalism rate did not differ significantly between the two housing systems. The analysis of causes of variation in productivity, mortality rate and cannibalism rate in aviaries revealed a strong effect of strain. Beak trimming was associated with a reduced prevalence of cannibalism rates but had no effect on overall mortality. It also reduced egg weight and food consumption. Early access to litter during the rearing period had a positive effect on egg weight; egg mass, food conversion and mortality rate. In conclusion, we found a slightly reduced productivity of aviaries in relation to cages although the mortality rates and the prevalence of cannibalism did not differ between these housing systems. To further improve productivity and reduce mortality of hens housed in aviaries we recommend the choice of suitable strains and the implementation of improved rearing conditions including early access to litte

Toward standardized reporting for a cohort study on functioning: The Swiss Spinal Cord Injury Cohort Study

OBJECTIVE: Functioning is an important outcome to measure in cohort studies. Clear and operational outcomes are needed to judge the quality of a cohort study. This paper outlines guiding principles for reporting functioning in cohort studies and addresses some outstanding issues.DESIGN: Principles of how to standardize reporting of data from a cohort study on functioning, by deriving scores that are most useful for further statistical analysis and reporting, are outlined. The Swiss Spinal Cord Injury Cohort Study Community Survey serves as a case in point to provide a practical application of these principles.METHODS AND RESULTS: Development of reporting scores must be conceptually coherent and metrically sound. The International Classification of Functioning, Disability and Health (ICF) can serve as the frame of reference for this, with its categories serving as reference units for reporting. To derive a score for further statistical analysis and reporting, items measuring a single latent trait must be invariant across groups. The Rasch measurement model is well suited to test these assumptions.CONCLUSION: Our approach is a valuable guide for researchers and clinicians, as it fosters comparability of data, strengthens the comprehensiveness of scope, and provides invariant, interval-scaled data for further statistical analyses of functioning.<br/

Respiratory function and respiratory complications in spinal cord injury: protocol for a prospective, multicentre cohort study in high-income countries

Introduction Pneumonia is one of the leading complications and causes of death after a spinal cord injury (SCI). After a cervical or thoracic lesion, impairment of the respiratory muscles decreases respiratory function, which increases the risk of respiratory complications. Pneumonia substantially reduces patient’s quality of life, may prolong inpatient rehabilitation time, increase healthcare costs or at worse, lead to early death. Respiratory function and coughing can be improved through various interventions after SCI, but the available evidence as to which as

Respiratory function and respiratory complications in spinal cord injury: protocol for a prospective, multicentre cohort study in high-income countries

Introduction Pneumonia is one of the leading complications and causes of death after a spinal cord injury (SCI). After a cervical or thoracic lesion, impairment of the respiratory muscles decreases respiratory function, which increases the risk of respiratory complications. Pneumonia substantially reduces patient’s quality of life, may prolong inpatient rehabilitation time, increase healthcare costs or at worse, lead to early death. Respiratory function and coughing can be improved through various interventions after SCI, but the available evidence as to which as

Seasonal variation in food supply and breeding success in European Coots Fulica atra

Chick survival in the European Coot typically shows a convex seasonal pattern. Previous experiments revealed that this pattern is directly linked to hatching date and that food supply within the first ten days after hatching is a causal factor in this relationship. However, the precise mechanism through which food affects survival seasonally under natural conditions remained so far unclear. The present study therefore investigates the natural seasonal variation in food abundance during brood care, and compares this variation in food supply with the seasonal variation in chick survival for different years. Annual and seasonal variation in chick survival was explained by Variation in the insect biomass delivered to the brood within the first ten days after hatching. The variation in insect supply to the chicks was not due to differences in the time spent by early and late pairs in feeding young, but directly related to seasonal variation in the insect biomass available. Seasonal variation in insect abundance was thereby identified as the critical factor in the causal relationship between hatching date, food supply and chick survival. [KEYWORDS: Fulica atra; hatching date; offspring survival; food availability; food supply; timing of reproduction; reproductive success Aythya-fuligula; hatch date; great tit; dreissena-polymorpha; size selection; growth-rate; time; population; survival; mussels]

The seasonal decline in the first-year survival of juvenile coots: An experimental approach

1. We investigated experimentally the seasonal variation in the local first-year survival of individual European coots, and introduced a method of survival analysis that extends the use of standard logistic regression. 2. Under natural conditions, survival of young showed a decline with hatching date. This decline differed in level, but not in slope, between cohorts. 3. To test whether the seasonal decline in survival was caused by a general regress in environmental conditions (the date hypothesis) or by differences in parental or territory quality between early and late breeders (the parental quality hypothesis), we cross-fostered clutches differing in laying date between pairs, thus establishing 'delayed' and 'advanced' pairs over most of the season. 4. Survival of young fostered by experimental pairs differed significantly from control young of the same hatching date, which defied the date hypothesis. In contrast, survival of experimental young was similar to that of control young, which hatched on the foster parent's original brood hatching date. The results were therefore consistent with the parental quality hypothesis. 5. Survival was essentially independent of size (tarsus length) for early-hatched young. Late-hatched young showed an initial increase in survival with tarsus length. At large sizes, the curve flattened to the level of the early-hatched young. 6. The small size of late-hatched young therefore largely explained the natural seasonal decline in survival. Variation in tarsus length did not account for the experimentally established effect of parental or territory quality differences on the seasonal decline in juvenile survival. [KEYWORDS: first-year survival probability; Fulica atra; hatching date; juvenile growth; parental quality Tit parus-major; kestrel falco-tinnunculus; laying date; brood-size; great tits; reproductive success; causal relationship; nestling weight; gosling growth; fulica-atra]

Productivity and mortality of laying hens in aviaries: a systematic review

A systematic review of investigations on productivity, mortality and cannibalism of laying hens housed in aviaries is presented. In Part One we reviewed the studies that compared these parameters between laying hens housed in aviaries and in conventional cages. In Part Two we investigated the relative impact of strain, beak trimming and rearing condition on productivity and mortality in aviaries. The comparative analysis revealed that aviary hens consumed 3.0 % more food than caged hens, and food conversion was 6.7 % higher in aviaries than in cages. On the other hand, the mortality rate and cannibalism rate did not differ significantly between the two housing systems. The analysis of causes of variation in productivity, mortality rate and cannibalism rate in aviaries revealed a strong effect of strain. Beak trimming was associated with a reduced prevalence of cannibalism rates but had no effect on overall mortality. It also reduced egg weight and food consumption. Early access to litter during the rearing period had a positive effect on egg weight; egg mass, food conversion and mortality rate. In conclusion, we found a slightly reduced productivity of aviaries in relation to cages although the mortality rates and the prevalence of cannibalism did not differ between these housing systems. To further improve productivity and reduce mortality of hens housed in aviaries we recommend the choice of suitable strains and the implementation of improved rearing conditions including early access to litter

Timing of reproduction and fledging success in the coot Fulica atra : evidence for a causal relationship

1. We investigated the relationship between hatching date and fledging success in the European coot (Fulica atra). 2. The production of fledglings per brood increased in the first half of the season and decreased in the second half, independent of clutch size or egg size. We tested experimentally whether this convex seasonal pattern is causally related to date. 3. The timing of parental care was manipulated by exchanging complete first clutches that differed in stage of incubation. Our experiments tested whether the natural variation in fledging success was due to (i) factors related to date (date hypothesis), (ii) factors related to parental and/or territory quality (parental quality hypothesis), or to a combination of both factors. 4. In the first half of the season, an experimental advance of the timing of parental care reduced fledging success, while an experimental delay raised it. In the second half of the season the opposite was found. Fledgling production by experimental pairs did not differ systematically from that of control pairs raising young at the same time. 5. Thus, the results were consistent only with the date hypothesis, and we conclude that timing of breeding and fledging success are causally related in the coot. 6. Independent of date, age of male parents was positively correlated with fledging success, suggesting that aspects of parental quality play an additional role

Non-pharmacological interventions for chronic pain in people with spinal cord injury

Background Chronic pain is frequent in persons living with spinal cord injury (SCI). Conventionally, the pain is treated pharmacologically, yet longterm pain medication is often refractory and associated with side effects. Non-pharmacological interventions are frequently advocated, although the benefit and harm profiles of these treatments are not well established, in part because of methodological weaknesses of available studies. Objectives To critically appraise and synthesise available research evidence on the effects of non-pharmacological interventions for the treatment of chronic neuropathic and nociceptive pain in people living with SCI. Search methods The search was run on the 1st March 2011. We searched the Cochrane Injuries Group's Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (OvidSP), Embase (OvidSP), PsycINFO (OvidSP), four other databases and clinical trials registers. In addition, we manually searched the proceedings of three major scientific conferences on SCI. We updated this search in November 2014 but these results have not yet been incorporated. Selection criteria Randomised controlled trials of any intervention not involving intake of medication or other active substances to treat chronic pain in people with SCI. Data collection and analysis Two review authors independently extracted data and assessed risk of bias in the included studies. The primary outcome was any measure of pain intensity or pain relief. Secondary outcomes included adverse events, anxiety, depression and quality of life. When possible, meta-analyses were performed to calculate standardised mean differences for each type of intervention. Main results We identified 16 trials involving a total of 616 participants. Eight different types of interventions were studied. Eight trials investigated the effects of electrical brain stimulation (transcranial direct current stimulation (tDCS) and cranial electrotherapy stimulation (CES); five trials) or repetitive transcranial magnetic stimulation (rTMS; three trials). Interventions in the remaining studies included exercise programmes (three trials); acupuncture (two trials); self-hypnosis (one trial); transcutaneous electrical nerve stimulation (TENS) (one trial); and a cognitive behavioural programme (one trial). None of the included trials were considered to have low overall risk of bias. Twelve studies had high overall risk of bias, and in four studies risk of bias was unclear. The overall quality of the included studies was weak. Their validity was impaired by methodological weaknesses such as inappropriate choice of control groups. An additional search in November 2014 identified more recent studies that will be included in an update of this review. For tDCS the pooled mean difference between intervention and control groups in pain scores on an 11-point visual analogue scale (VAS) (0-10) was a reduction of -1.90 units (95% confidence interval (CI) -3.48 to -0.33; P value 0.02) in the short term and of -1.87 (95% CI -3.30 to -0.45; P value 0.01) in the mid term. Exercise programmes led to mean reductions in chronic shoulder pain of -1.9 score points for the Short Form (SF)-36 item for pain experience (95% CI -3.4 to -0.4; P value 0.01) and -2.8 pain VAS units (95% CI -3.77 to -1.83; P value <0.00001); this represented the largest observed treatment effects in the included studies. Trials using rTMS, CES, acupuncture, self-hypnosis, TENS or a cognitive behavioural programme provided no evidence that these interventions reduce chronic pain. Ten trials examined study endpoints other than pain, including anxiety, depression and quality of life, but available data were too scarce for firm conclusions to be drawn. In four trials no side effects were reported with study interventions. Five trials reported transient mild side effects. Overall, a paucity of evidence was found on any serious or long-lasting side effects of the interventions. Authors' conclusions Evidence is insufficient to suggest that non-pharmacological treatments are effective in reducing chronic pain in people living with SCI. The benefits and harms of commonly used non-pharmacological pain treatments should be investigated in randomised controlled trials with adequate sample size and study methodology