Wing Stretch Research Articles

Effect of Different Stocking Densities as an Environmental Stressing Factor on Broiler Behavior and Performance

Six hundreds of unsexed Arbor Acres chicks were used and housed in symmetrical 9 pens withthree levels of stocking12 bird/m2, 15 bird/m2 and 20 bird/m2. Productive performance parameterswere measured including, average daily Feed intake, average body weight, average weekly weightgain, feed conversion rate (FCR), mortality rate, dressing yield and visceral organs weight.Behavioral observations including feeding, drinking, leg scratching, leg -wing stretching, preening,litter eating and dust bathing were done by scan sampling, birds were observed 3 days /week.Results revealed that the growth performance within the first and second weeks, the high stockingdensity group (20 bird/m2) showed a high feed intake, body weight and body weight gain, followedby medium stocking density group (15 bird / m2) and the lowest performance parameters throughthe first two weeks were recorded in the control group. From the fourth to the fifth weeks, mediumdensity group (15 bird / m2) showed a higher feed intake body weight and body weight gain. Themoderate stocking density achieved a higher final body weight was 1954 ±1.73 g, body weight gain1911.75 ±1.73 g, also feed intake passed in the same direction MSD consumed 3117.19 ±11.4 g/bird. Finally, all group showing the same feed conversion ratio as all different stocking densitiesshowing no significant differences in FCR. The results carcass characteristics showed that themoderate stocking density group (15 bird/ m2) achieve the highest dressing weight and higherdressing percentage compared with other two groups. Regarding to internal organ weight thecontrol group showed the highest gizzard, liver, and heart weights followed by moderate and highstocking density group respectively. the results clearly showed that increasing SD significantlyreduced the weights of the lymphoid organs. Behavioral Indicators showed that within the first twoweeks, the feeding and drinking behavior was significantly differ, as the moderate and high densitygroups showing the higher feeding than control group. The final feeding and drinking behaviorwithin the whole experimental period, there was no statistical significant difference between thedifferent groups. The welfare behavior indicators, including leg and wing stretch, leg scratch,preening and resting behavior were recorded within five weeks and also from total means for allgroup it was clear that from the first week till the end of experiment the stocking density negatively correlated to the welfare behavior indicators. Regarding to resting behavior within weeks and in allover means in the different groups although there was no significant difference between different groups as p > 0.05 there was a decrease in the resting behavior percentage with increased stocking density.

EVALUATION OF BEHAVIOR AND WELFARE IN BROILERS REARED IN TWO DIFFERENT HOUSING SYSTEMS

An experiment was conducted to evaluate the effect of different housing system (cages vs. floor system) on behavioral patterns and welfare of broiler chicks. One hundred and twenty broiler were allocated in to two housing system (cages and floor pen) in full environmental controlled pens for four weeks. Assessment of welfare was through measuring general behavioral, tonic immobility test and heterophil: lymphocyte ratio (HLR). Compared to cage reared birds, floor reared broilers exhibit higher level of feeding, drinking, crouching, walking behavior while caged birds were more often standing and also showed either more wing stretch, leg stretch or both wing& leg stretch than floor reared group. Moreover, shortest duration of tonic immobility test was observed in floor reared birds than those housed in cages. HLR were significantly higher in cages than floor group. At the end of this experiment our obtained data suggested that housing in cages has adverse effect on welfare as it impair general behavioral patterns, birds showed more fearfulness also higher HLR which over all indicated stressful conditions for birds. In conclusion, cages should not be recommended for broiler rearing from welfare point of view.

Growth Performance of Guinea Fowl Fed Diets Containing Yellow Maize, Millet and White Sorghum as Energy Sources and Raised under Intensive System

This study investigated growth performance of guinea fowl fed diets containing 3 cereal grains as energy sources in comparison to commercial broiler diets. Birds were raised under intensive system from 3 to 16 weeks of age. A completely randomized design was used where 160 keets were randomly assigned to 4 dietary treatments. Each treatment had 40 birds with 4 replicates of 10 birds each. Data were analyzed using General Linear Model Procedure of Statistical Analysis Software (version 9.0). The results showed that dietary treatment did not (P>0.05) influence body length, body circumference, wing stretch, shank length and neck length of guinea fowl. From 3 to 16 weeks of age feed intake was significantly (P<0.0001) lower for control diet (13714.79±209.65 g) than maize (16085±209.65 g), millet (1609.63±209.65 g) and sorghum (15872±209.65 g) diets. Furthermore, FCR was significantly (P<0.0001) lower on control diet (11.33±0.37) than maize (13.91±0.37), millet (14.90±0.37) and sorghum (13.72±0.37) diets. Average weekly body weight gain was significantly (P<0.05) lower for birds on millet diet (82.98±2.18 g) than birds on control (93.14±2.18 g), maize (89.25±2.18 g) and sorghum (89.03±2.18 g) diets. These results suggest that cereal grains can be used in guinea fowl diets without affecting performance

A ROLE FOR SENSORY INPUTS IN THE GENERATION OF THE FLIGHT MOTOR PATTERN

> [⇓][1] > > Jeremy Niven discusses Malcolm Burrows' 1975 paper entitled: ‘Monosynaptic connexions between wing stretch receptors and flight motoneurones of the locust’. > > A copy of the paper can be obtained from ![Figure][2]</img

Locust wing stretch receptor adaptation and recovery from adaptation

Adaptation of action potential frequency is a common feature of neurons from various parts of the nervous system. Adaptation is thought to contribute to information coding, integration, input filtering and saving of metabolic resources. Despite inten sive investigation, the kinetics of adaptation and recovery from adaptation are not fully described. The locust forewing stretch receptor (fSR) was used to investigate the kinetics of adaptation and recovery from adaptation in response to wing elevation. We have found that adaptation can be well described by a sum of two exponential decays with time constants 5.04 ± 0.6 s and 24.86 ± 2.45 s. The dependence of recovery on adaptation time was biphasic in 70% of the fSRs investigated. In these fSRs, the break point (10.54 ± 1.09 s) separates the initial linear phase from the following exponential one. These findings suggest that at least two mechanisms with different kinetics are involved in the adaptation of locust wing stretch receptor.

Skėrio sparno vyrio tempimo receptoriaus atsako adaptacija esant dinaminiam režimui

* Corresponding author: E-mail: osvaldas.ruksenas@gf.vu.lt Locust wing stretch receptor is known to exhibit fi ring frequency adaptation when the forewing is lift ed to a constant position. However, during fl ight, the wing periodically moves and the receptor’s response properties are in this dynamic mode unknown. We recorded extracellularly the response from the Locusta migratoria forewing stretch receptor while the wing was periodically lift ed and found that the adaptation of the stretch receptor is expressed in a dynamic mode as well; however, this adaptation is weaker than in the static mode.

GABA immunoreactivity in processes presynaptic to the locust wing stretch receptor neuron

GABA immunoreactivity in processes presynaptic to the locust wing stretch receptor neuron

GABA immunoreactivity in processes presynaptic to the locust wing stretch receptor neuron

Studies on the locust Locusta migratoria (Leitch et al. [1998] Soc. Neurosci. Abstr. 624.10) suggest that gamma-aminobutyric acid (GABA)ergic interneurons, activated via muscarinic receptors, may be involved in modulation of transmitter release at synapses between the forewing stretch receptor (fSR) and wing depressor motoneurons. To help elucidate the role GABAergic interneurons may play in modulation of transmitter release from fSR terminals, the proportion and distribution of GABA-immunoreactive (GABA-IR) inputs to the fSR were analysed using double-labelling (horseradish peroxidase and GABA immunocytochemistry) and electron microscopy. Forty-three percent of synaptic inputs to the fSR were from GABA-IR profiles, the majority of which were located on lateral branches. The highest proportion (57%) of inputs to the fSR, however, were from non-IR processes containing either clear spherical vesicles or mixed clear and dense-cored vesicles. Outputs from the fSR to GABA-IR profiles were also found, although their number was relatively low (7%). Networks were identified in which both the fSR and its non-IR postsynaptic partner received input from the same GABA-IR neuron. Such an arrangement would allow both pre- and postsynaptic inhibition of fSR afferent outputs, for example at fSR/motoneuron synapses. These observations demonstrate that the fSR does receive presynaptic inputs from GABA-IR neurons, thus providing morphological support for pharmacological and electrophysiological findings that GABAergic neurons are involved in the presynaptic modulation of the fSR. Nevertheless, modulation at this synapse may be more intricate and involve other, as yet unidentified, neurotransmitters released from non GABA-IR presynaptic processes and also muscarinic receptors located on the fSR itself.

Modulation of transmitter release from the terminals of the locust wing stretch receptor neuron by muscarinic antagonists

The forewing stretch receptor (SR) neuron makes monosynaptic connections with wing depressor motoneurons; in this article the pharmacology of its output onto the first basalar motoneuron (BA1) has been investigated. The SR, like other insect afferents that have been studied so far, appears to be cholinergic; transmission was suppressed reversibly by the nicotinic antagonist gallamine (10(-4) M) and irreversibly by alpha-bungarotoxin (10(-6) M). The choline reuptake blocker hemicholinium-3 (10(-4) M) also caused a reversible reduction in the amplitude of SR excitatory postsynaptic potentials (EPSPs) recorded in BA1. The receptor subtype nonselective muscarinic antagonists atropine (10(-4) M), scopolamine (10(-4) M), and quinuclidinyl benzilate (10(-5) M), unlike nicotinic antagonists, caused an augmentation in EPSP amplitude. This effect does not appear to be caused by an increase in sensitivity of the motoneuron to acetylcholine (ACh), since atropine produced a marked reduction rather than an increase in the amplitude of responses to ACh pressure applied to the soma of BA1. Scopolamine only caused a modest reduction in the amplitude of ACh somatic responses. The simplest explanation for these observations is that muscarinic antagonists bring about an increase in EPSP amplitude by blockade of presynaptic autoreceptors that normally down-regulate the release of ACh from SR terminals. The effects of muscarinic receptor subtype-selective antagonists indicate that presynaptic receptors in this preparation may have a pharmacological profile more similar to that of vertebrate M2 receptors than to that of M1 or M3 subtypes. The functional significance of autoreceptors in this preparation are discussed.

Entrainment of the locust central flight oscillator by wing stretch receptor stimulation

1. Experiments were designed to examine phase-dependent influences of the wing stretch receptor (SR) afferents on the central oscillator in the flight system of the locust. Reasons were also sought for the failure of earlier workers to find phase-dependent influences of SR activity on the flight oscillator. 2. In preparations with the hindwing sensory nerves left intact, electrical stimulation of the two forewing SRs caused an immediate increase in oscillator frequency reaching a maximum of 16–20 Hz as described by Pearson et al. (1983). After cutting the hindwing sensory nerves, the same stimulation increased the frequency from 6–8 Hz to 12–14 Hz. The absolute reduction in cycle period caused by the stimulation was reduced from 15–25 ms to 10–15 ms as a result of cutting the hindwing sensory nerves. 3. Stimulation of two forewing SRs in completely deafferented preparations in bursts occurring at a constant rate could entrain the flight oscillator. During entrainment, depressor spikes occurred close to the time of the stimulus. The flight oscillator could follow changes in the entrainment frequency, usually only up to 1 Hz (10% cycle period) compared to 4–6 Hz (40–50% cycle period) seen by Pearson et al. (1983). Entrainment could still be elicited when the chordotonal organ afferents were co-stimulated. 4. Bilateral stimulation of the hindwing SRs could also entrain the central flight oscillator over a similar range of frequencies as was observed for forewing SR stimulation. 5. Stimulation of a lateral pair of SRs (one forewing and the ipsilateral hindwing SR) was observed to produce 1∶1 entrainment in only one out of fifteen animals. However, a phase-dependent influence on the oscillator rhythm could be demonstrated by stimulation time-locked to the oscillator output (depressor EMG). SR stimulation close to the time of the depressor spike increased the oscillator frequency and prolonged the duration of rhythmic activity. Stimulation occurring approximately midway between depressor bursts had no obvious effect on the frequency or duration of the oscillator rhythm. 6. The only conditions under which a slow increase in oscillator frequency could be produced by stimulation of a lateral pair of SRs was when the SR stimulus frequency was set much higher than the central oscillator frequency. It is concluded that the failure of earlier workers to observe phase-dependent effects of SR stimulation on the oscillator frequency was due to stimulation of a lateral rather than segmental pair of SRs and the method they used in their attempt to demonstrate phase-dependence. Their observation of a slow phase-independent increase in flight frequency possibly resulted from the high SR stimulus frequencies employed.

Phase-dependent influences of wing stretch receptors on flight rhythm in the locust.

Phase-dependent influences of wing stretch receptors on flight rhythm in the locust.

Monosynaptic connexions between wing stretch receptors and flight motoneurones of the locust

1. The connexions between stretch receptors of the wings and motoneurones innervating flight muscles have been studied anatomically and physiologically. 2. Filling with cobaltous chloride shows that the single neurone of a forewing stretch receptor has a complex pattern of branches within the mesothoracic ganglion and branches which extend into the pro- and meta-thoracic ganglia. The single neurone of a hindwing stretch receptor has extensive branches in the metathoracic ganglion and branches in themesothoracic ganglion. The branches of both receptors are confined to the ipsilateral halves of the ganglia. 3. A stretch receptor gives information about the velocity and extent of elevation of a wing. 4. Each spike of a forewing stretch receptor casuses an EPSP in ipsilateral mesothoracic depressor motoneurones and an IPSP in elevators. The connexions are thought to be monosynaptic for the following reasons. The EPSPs in the first basalar (depressor) motoneurone follow each spike of the stretch receptor at a frequency of 125 Hz and with a constant latency of about 1 msec. In a Ringer solution containing 20 mM-Mg2+ the amplitude EPSP declines gradually. The IPSP'S upon elevators have similar properties but occur with a latency of 4-6 msec. 5. The connexions therefore comprise a monosynaptic negative feed-back loop; elevation of the wing excites the stretch receptor which then inhibits the elevator motoneurones and excites the depressors. 6. A hindwing stretch receptor synapses upon metathoracic flight motoneurones in the same way, causing EPSPs in depressor and IPSPs in elevator motoneurones. 7. No connexions of either fore- or hindwing stretch receptors have been found with contralateral flight motoneurones. 8. Interganglionic connexions are made by both receptors. For example, both fore- and hindwing stretch receptors cause EPSPs upon the meso- and metathoracic first basalar motoneurones. 9. Stimulation of the axon of a stretch receptor with groups of three stimuli repeated every 50-100 msec thus simulating the pattern which it shows during flight, causes subthreshold waves of depolarization in depressor motoneurones. When summed with an unpatterned input, the stretch receptor is able to influence the production of spikes in motoneurones on each cycle. During flight, it is expected that the stretch receptor will influence the time at which a motoneurone will spike and hence have an effect on the amplitude of the upstroke and upon the phase relationship between spikes of motoneurones.

The development of the flight pattern in the desert locust, Schistocerca gregaria

The responses of the desert locust, Schistocerca gregaria, to air currents and light flashes were observed throughout the animals' development. Animals in the first stage respond by raising their legs, in later stages the “flight” position is assumed. In larvae exhibiting the “flight” position, electrical recordings demonstrate a tonic activity of the thick thoracic muscles. A pattern that can be said to be the typical flight pattern is first seen during the day following the imaginai ecdysis. During the three weeks after this ecdysis the wingbeat frequency increases exponentially from 10 to 20 Hz. Destruction of the wing stretch receptor organs in young adults causes immediate decreases in flight frequency like in older adults. A learning process is unlikely to be involved in flight pattern formation. Possible explanations of the frequency increase are discussed.

DESCRIPTION OF A NEW BRONCHELIA

Bronchelia gravilinearia, n. sp.The general ground color of this species is a light brown, approaching a fawn color. The palpi, however, are of a dark brown.F. w.—Wing stretch 1¾ in. There are five distinct, dark brown,transverse bands, all commencing on the costa. The first two basal and rather close to each other; the inner of the two somewhat broken. The third very heavy. The fourth is much narrower than the third, and commences on the costa at about one-tenth of an inch from the third, curving until it touches it at about mid-wing, thence running nearly confluent with it to inner margin. The fifth band is not quite so heavy as the third, and is broken at about the third nervule. All the bands curve towards the base, but are not quite parallel. The space between the fifth band and outer margin is thickly .covered with scales of the same dark brown as the bands. Outer margin slightly notched, with a row of dark brown lunar marks. All the bands, except one and two, are extended across the hind wings.