Broiler chickens are increasingly at the forefront of global meat production but consequences fast growth and selection for an increase in body mass on bird health ongoing concern industry consumers. To better understand implications we evaluated energetics behaviour over 6-week hatch-to-slaughter developmental period a commercial broiler. The effect posture resting metabolic rate becomes significant as broilers grow, standing became more energetically expensive than sitting. proportion...

Genetic selection for improved meat yields, digestive efficiency and growth rates have transformed the biology of broiler chickens. Modern birds undergo a 50-fold multiplication in body mass just six weeks, from hatching to slaughter weight. However, this rapid improvements productivity is also widely thought be associated with increased welfare problems as many suffer leg, circulatory respiratory diseases. To understand growth-related changes musculoskeletal organ morphology skeletal...

SUMMARY The activity of three muscles associated with the uncinate processes, (i)external intercostal, (ii) appendicocostalis and (iii) external oblique, were examined using patch sew-through electrodes during sitting, standing moderate speed treadmill running in giant Canada goose. intercostal demonstrated no respiratory activity, being active only running, suggesting they play some role trunk stabilisation. oblique are muscles, inspiration expiration, respectively. increased that processes...

In 1868 Thomas Huxley first proposed that dinosaurs were the direct ancestors of birds and subsequent analyses have identified a suite ‘avian’ characteristics in theropod dinosaurs. Ossified uncinate processes are found most species extant also occur extinct non-avian maniraptoran Their presence these represents another morphological character linking them to Aves, further supports an avian-like air-sac respiratory system dinosaurs, prior evolution flight. Here we report phylogenetic...

The functional significance of the uncinate processes to ventilatory mechanics birds was examined by combining analytical modeling with morphological techniques. A geometric model derived determine function and relate their action differences associated locomotor specializations. demonstrates that uncinates act as levers, which improve mechanical advantage for forward rotation dorsal ribs therefore lowering sternum during respiration. length these is functionally important; longer increasing...

In broiler chickens, genetic success for desired production traits is often shadowed by welfare concerns related to musculoskeletal health. Whilst these are clear, a viable solution still elusive. Part of the lies in knowing how anatomical changes afflicted body systems that occur across ontogeny influence standing and moving. Here, demonstrate we quantify segment inertial properties whole body, trunk (legs removed) right pelvic limb segments five broilers at three different age groups...

The brain is energetically expensive. Energy availability may, therefore, determine whether costly cognitive processes such as long-term memory can be expressed. However, there a limited understanding of the metabolic costs associated with formation. Here, we explored potential induced formation using honeybees ( Apis mellifera ) model species. We monitored sucrose intake bees over 20-hour period following classical spaced olfactory conditioning protocol that formation, relative to control...

Svalbard rock ptarmigans were walked and run upon a treadmill their energy expenditure measured using respirometry. The ptarmigan used three different gaits: walking gait at slow speeds (less than or equal to 0.75 m s(-1)), grounded running intermediate (0.75 s(-1) < U 1.67 s(-1)) aerial high (greater s(-1)). Changes of associated with reductions in the gross cost transport (COT; J kg(-1) m(-1)), providing first evidence for savings change small crouched-postured vertebrate. In addition,...

Abstract In light of evidence for avian‐like lungs in saurischian dinosaurs, the physiological implications cross‐current gas exchange and voluminous, highly heterogeneous sauropod gigantism are critically examined. At 12 ton predicted body temperature metabolic rate a growing would be similar to that bird scaled same weight, but increase exponentially as mass increases. Although lung structure consistent with either tachymetabolic‐endothermic or bradymetabolic‐gigantothermic model,...

Little is known regarding the physiological consequences of behavioural and morphological differences that result from sexual selection in birds. Male female Svalbard rock ptarmigans ( Lagopus muta hyperborea ) exhibit distinctive during breeding season. In particular, males continuously compete for defend territories order to breed successfully, placing large demands on their locomotor system. Here, we demonstrate male birds have improved performance compared with females, showing both a...

Wind tunnel tests conducted on a model based the long-eared bat Plecotus auritus indicated that positioning of tail membrane (uropatagium) can significantly influence flight control. Adjusting position by increasing angle legs ventrally relative to body has two-fold effect; leg-induced wing camber (i.e., locally increased inner surface) and attack membrane. We also used our examine effects flying with without For leg lift, drag pitching moment (nose-down) produced. However, removing reduced...

Abstract Exaggerated traits, like the peacock train, are recognized as classic examples of sexual selection. The evolution traits is often considered paradoxical as, although they enhance reproductive success, widely presumed to hinder movement and survival. Many exaggerated represent an additional mechanical load that must be carried by animal therefore may influence metabolic cost locomotion constrain locomotor performance. Here we conducted respirometry experiments on peacocks demonstrate...

The Svalbard rock ptarmigan, Lagopus muta hyperborea experiences extreme photoperiodic and climatic conditions on the Arctic archipelago of Svalbard. This species, however, is highly adapted to live in this harsh environment. One most striking adaptations found these birds deposition, prior onset winter, fat stores which may comprise up 32% body mass are located primarily around sternum abdominal region. fat, while crucial birds' survival, also presents a challenge that bird must maintain...

ABSTRACT The current hypothesis regarding the mechanics of breathing in crocodylians is that double-headed ribs, with both a capitulum and tuberculum, rotate about constrained axis passing through two articulations; moreover, this shifts caudal thoracic as vertebral parapophysis moves from centrum to transverse process. Additionally, ventral ribcage thought possess additional degrees freedom mobile intermediate ribs. In study, X-ray reconstruction moving morphology (XROMM) was used quantify...

Abstract Sex differences in locomotor performance may precede the onset of sexual maturity and/or arise concomitantly with secondary sex characteristics. Here, we present first study to quantify terrestrial morphology, energetics and kinematics a species, either side maturation. In domestic leghorn chickens ( Gallus gallus domesticus ) maturation brings about permanent female gravidity increased male hind limb muscle mass. We found that sexes juvenile cohort leghorns shared similar maximum...

Abstract A central concept of evolutionary biology, supported by broad scale allometric analyses, asserts that changing morphology should induce downstream changes in locomotor kinematics and energetics, inference selective fitness. However, if these mechanistic relationships exist at local intraspecific scales, where they could provide substrate for fundamental microevolutionary processes, is unknown. Here, analyses selectively-bred duck breeds demonstrate distinct body shapes incur...

Abstract Insects are successful terrestrial organisms able to locomote over a wide range of obstacles and substrates. This study investigated how foot morphology (tarsal structure) correlates with substrate adhesion ecological niche in the Madagascan hissing cockroach, Gromphadorhina portentosa Schaum (Blattaria: Blaberidae). Using light scanning electron microscopy, different structures tarsus G. was analysed. an Instron® universal testing machine, series peak force experiments were then...

Most studies relating bat morphology to flight ecology have concentrated on the wing membrane. Here, canonical variance analysis showed that ear and tail morphologies of bats also strongly relate foraging strategy, which in turn is correlated with style. Variations membrane are likely be a trade-off between increases mechanical cost improvements performance. Flying large ears potentially energetically expensive, particularly at high speeds. Large ears, therefore, only affordable for slow...