Sign in Sign up. Thank you for your participation! Document related concepts. Undulatory locomotion wikipedia , lookup Role of skin in locomotion wikipedia , lookup Comparative foot morphology wikipedia , lookup Human leg wikipedia , lookup. These body parts interact and cooperate to allow the chicken to perform a variety of activities such as walking, hopping, sitting, and standing.
In this investigation, the various tissues and structures of the leg of a chicken will be found and described. As you investigate the chicken foot you will see the muscles which are a dark pink tissue that surrounds the bone. You will also see silvery white tough connective tissue, this is the tendon that attaches the muscle to the bone. Muscles move in antagonistic opposite pairs to move a bone. So for every movement there should be a pair of tendons. One muscle and tendon to contract and close the joint, and another tendon and muscle to relax or open the joint.
The chicken foot has long easy to reach tendons which make the foot ideal to use. Chickens actually walk on their toes and NOT on their feet. If you were to remove all the skin you will see the ligaments, a whitish tissue that holds bones together. The thin strand of material along the muscle is the nerve.
The nerves are what send messages from the brain to different parts of the body, such a muscles or from sensory organs to the brain. Problem: How is movement produced in a chicken foot?
Birds appear to use visual cues and they emphasize safety when moving over uneven terrain They may accomplish this using active neural control of leg mechanics. For example, pheasants Phasianus colchicus control their limb during placement to achieve stability when walking or running over uneven terrain As falls and collisions are at least partly responsible for KBD in chickens 3 , we hypothesize that adaptive, anticipatory movements will improve safety for chickens navigating ramps within aviaries, but we do not presently know whether chickens respond to visual cues about incline and adjust their locomotor behavior.
Furthermore, nothing is known about how developmental age affects adaptive locomotion in birds, and beginning to address this gap in knowledge is one of our objectives herein.
As part of our overall goal of elucidating causes and solutions to reduce the frequency of KBD, we undertook the present study to test whether incline angle and developmental age affect adaptive locomotion in domestic chickens. Morphology changes during development, so we measured body mass and leg length to test for effects of these variables upon performance We measured forces exerted by the birds via their leg and foot upon the ground to test for preincline, anticipatory behavior in domestic chickens.
Higher vertical peak forces from the leg and foot increase climb velocity at the start of the ramp, reduced range in COP excursion and COP sway velocity indicating greater postural stability, and increased foot contact time permits active control of limb posture We predicted such anticipatory behavior would vary with increasing age during development, as is the case for overall climb performance in related bird species 9 , Twenty female domestic chickens Gallus gallus domesticus comprising four strains Lohmann Brown, Lohmann LSL, Dekalb White, and Hyline Brown aged 17 weeks were divided into four home pens with five birds of a given strain per pen.
An elevated, spring mounted to simulate natural compliance in a tree-branch perch spanning the width of the pen, was mounted 14 cm above the highest platform toward the rear end of the pen, with the two halves of the perch different in diameter 2. The pens also featured automatic drinkers, nest boxes, and a feeder. The light cycle was h light:dark, with a min dawn and dusk. The light intensity was 50 lux. We constructed a ramp apparatus Figure 1 with an adjustable ramp incline in a test room.
The ramp itself was cm wide without directly adjacent walls. The ramps were covered with 2. In separate experiments 4 , we confirmed that the ramp being cm wide did not inhibit chickens from using their wings for balance or flapping them in WAIR; the same ramp widths are used in comparable studies of wild-type Gallifomes 9 , 10 , We used an internal digital preamplifier Bertec AM The bit digital signal was transferred to computer via RS Bertec Digital Acquire software version 4.
A Loess model local regression smoothing process in R version 3. Our variables for subsequent analysis included onset and offset time of ground reaction force t 1 and t 2 ; s , peak vertical force F z , N , range of excursion of the COP about the fore-aft x and lateral y axes meters; COP x and COP y , respectively.
Birds were placed in the start box for a period of 3 s until the start door was lifted by the experimenter. The bird had 60 s determined from pilot study to walk out of the start box, step on the force plate, and climb up the ramp.
Birds were provided with motivation to climb using five pen mates in a crate on the elevated platform in addition to providing a tablespoon of their commercial feed along with five raisins. Each bird was given a second attempt if she failed in the first trial, defined as refusing to move up the ramp, moving away from the ramp apparatus, reaching the 60 s maximum to ascend the incline, or failing to step on the force plate.
Only one trial was subsequently analyzed. Only trials where the bird placed one entire foot on the force plate were used for quantitative analysis in this study. The videos served to see the entire bird and to confirm placement of one or two feet on the force plate. We measured the weight and limb dimensions of the birds to aid in interpretation of changes in locomotor performance according to age.
Birds were weighed at the end of 17, 21, 26, 31, and 36 weeks of age. We used Image J v1. Summary morphological data are presented in Table 1. Our statistical analysis was designed to test whether incline angle significantly affected the forces and timing of anticipatory behavior.
In addition, we tested for effects of age and strain upon these forces and timing. We initially categorized step events according to whether the stance phase featured one or two feet in contact with the plate. To focus on single-leg forces, we limited our subsequent analysis to the tests where the birds placed one foot on the force plate. Because each chicken was repeatedly tested at different ages and inclines, we conducted a repeated measures variance analysis for each variable.
Strain of the birds was removed from analysis, as there were no significant strain effects. We also conducted analysis of variance for the tibiotarsus, tarsometatarsus, and total limb length, with age of the birds was included as the fixed effect. To prepare for aerial ascent using hindlimb thrust and wing flapping, the birds placed both of their feet on the force plate, directly in front of the ramp. Summary statistics for force variables are presented in Table 2.
The magnitude of the peak vertical GRFs relative to bodyweight showed a significant increase at the greatest angle F 2, Table 2. Tendons attach muscle to bone.
Tendons, which attach our toes to upper support bones are very long and can be easily found. Muscles move in antagonistic opposite pairs to move a bone. So for every movement there should be a pair of tendons. One muscle and tendon to contract and close the joint, and another tendon and muscle to relax or open the joint. The chicken foot has long easy to reach tendons which make the foot ideal to use.
Chickens actually walk on their toes and NOT on their feet. Place the chicken foot in your dissecting pan. Examine the tough outer layer covering the outside. Describe this outer layer. For example, is there any hair or feathers present? What is the texture of the layer like? How is the outer layer skin of the chicken foot different from the outer layer of your foot skin? Find the silvery white tough connective tissue that is near the top of the foot next to the bone.
Pull this silvery mass from under the skin with your fingers. Holding the mass of tendons, PULL!!! What happened to the toes? Now separate each tendon from the bundle and pull separately. How many individual tendons are there? Now do the same thing to the front of the foot.
Slit the skin and find the tendons.. What happens to the toes? What happens when you stop pulling these tendons? Pull each separate tendon like you did with the last bundle. Are these 2 sets of tendons antagonistic pairs? Explain b. When the chicken was alive what were the tendons attached to?
0コメント