Effects of treadmill exercise on the distribution of blood flow between the hindlimb muscles and abdominal viscera of the laying fowl

Brackenbury, J. H.; Elsayed, Mahmoud; Darby, C

doi:10.1080/00071669008417247

Cited by 9 publications

(4 citation statements)

References 16 publications

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“…Results are presented as means 1 SD as a percentage of the total flow which is the sum of flows to all listed organs (mil mini per g). Asterisks denote significant differences (P < 0-05, paired t-test) Brackenbury et al (1990) found that 90 min continuous treadmill exercise only slightly affected blood flow distribution in the laying fowl, the only notable change being a significant reduction in the relative perfusion of the pre-ovulatory follicles. The exercise stimulus to the circulatory system cannot be directiy compared with that of hyperthermia, but it is noteworthy that neither provided a sufficient challenge to divert blood appreciably away from the reproductive system.…”

Section: Blood Flow To Abdominal Viscera and Skeletal Musclesmentioning

confidence: 94%

“…As part of a series of studies on the impact of environmental Stressors on blood flow to the reproductive system of unrestrained domestic fowl, we recently reported that moderate forced exercise had only a limited effect (Brackenbury et al, 1990). We wondered, therefore, to what extent the findings of Wolfenson et al (1981) might have been influenced by the fact that the chickens were restrained during the experiments.…”

Section: Introductionmentioning

confidence: 97%

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Effect of acute heat exposure on blood flow and its distribution in the unrestrained laying fowl (Gallus domesticus)

Arad

Elsayed

Brackenbury

1993

British Poultry Science

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1. The effect of heat exposure (air temperature 35-45°C) for 1.5 h on blood flow distribution between the abdominal viscera and the muscles of abdominal wall and hind leg was investigated in unanaesthetised, unrestrained laying fowl. 2. Heat stressed fowl showed a significant hyperthermia (+ 1.3°C), rapid shallow breathing (229 breaths/min) and significant hypocapnia ( -8 Torr). 3. Significant increases in absolute blood flow (ml/g per min) were measured in the kidneys, spleen, liver and duodenum during hyperthermia, but there was no change in the absolute blood flow to the reproductive tract or the relative perfusion of the reproductive tract compared with the other tissues sampled. 4. We conclude that in these acute conditions of heat exposure, blood flow to the reproductive tract of the laying fowl is not compromised by any simultaneous thermoregulatory needs.

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Section: Blood Flow To Abdominal Viscera and Skeletal Musclesmentioning

confidence: 94%

Section: Introductionmentioning

confidence: 97%

Effect of acute heat exposure on blood flow and its distribution in the unrestrained laying fowl (Gallus domesticus)

Arad

Elsayed

Brackenbury

1993

British Poultry Science

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“…2). A related bird, the domestic fowl, also shows no evidence for redistribution of blood flow away from the gut during exercise (Brackenbury et al 1990, 1993). In many other vertebrates studied to date, visceral blood flow decreases during exercise (Rowell, 1974; Laughlin & Armstrong, 1982; Manohar, 1986; Armstrong et al 1987).…”

mentioning

confidence: 99%

Blood flow in guinea fowl Numida meleagris as an indicator of energy expenditure by individual muscles during walking and running

Ellerby

Henry

Carr

et al. 2005

The Journal of Physiology

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Running and walking are mechanically complex activities. Leg muscles must exert forces to support weight and provide stability, do work to accelerate the limbs and body centre of mass, and absorb work to act as brakes. Current understanding of energy use during legged locomotion has been limited by the lack of measurements of energy use by individual muscles. Our study is based on the correlation between blood flow and aerobic energy expenditure in active skeletal muscle during locomotion. This correlation is strongly supported by the available evidence concerning control of blood flow to active muscle, and the relationship between blood flow and the rate of muscle oxygen consumption. We used injectable microspheres to measure the blood flow to the hind-limb muscles, and other body tissues, in guinea fowl (Numida meleagris) at rest, and across a range of walking and running speeds. Combined with data concerning the various mechanical functions of the leg muscles, this approach has enabled the first direct estimates of the energetic costs of some of these functions. Cardiac output increased from 350 ml min −1 at rest, to 1700 ml min −1 at a running speed (∼2.6 m s −1 ) eliciting aV O 2 of 90% ofV O 2 ,max . The increase in cardiac output was achieved via approximately equal factorial increases in heart rate and stroke volume. Approximately 90% of the increased cardiac output was directed to the active muscles of the hind limbs, without redistribution of blood flow from the viscera. Values of mass-specific blood flow to the ventricles, ∼15 ml min −1 g −1 , and one of the hind-limb muscles, ∼9 ml min −1 g −1 , were the highest yet recorded for blood flow to active muscle. The patterns of increasing blood flow with increasing speed varied greatly among different muscles. The increases in flow correlated with the likely fibre type distribution of the muscles. Muscles expected to have many high-oxidative fibres preferentially increased flow at low exercise intensities. We estimated substantial energetic costs associated with swinging the limbs, co-contraction to stabilize the knee and work production by the hind-limb muscles. Our data provide a basis for evaluating hypotheses relating the mechanics and energetics of legged locomotion.

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“…Recent studies have shown that plasma free fatty acids are the most important source of energy for the working muscles of exercising birds Brackenbury, 1987, 1988a, 19886;Brackenbury et al, 1987;Brackenbury and Vincent, 1988;Brackenbury and El-Sayed, 1989). It was also noted that exercise influences mitochondrial density, capillary vessel and blood flow distribution of birds (Brackenbury et al, 1990(Brackenbury et al, , 1993Brackenbury and Holloway, 1991).…”

Section: Introductionmentioning

confidence: 94%

Effects of heat production attributable to forced walking on thermoregulatory physiological responses of chickens in a warm environment

Zhou

Wang

Yamamoto

1996

British Poultry Science

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1. To determine the effects of heat production on thermoregulatory physiological responses, 5 chickens were forced to walk to increase heat production. The study consisted of two experiments. One involved 3 walking speeds (8, 16 and 24 m/min) at 25 degrees C ambient temperature. The other involved a single walking speed of 16 m/min at 3 ambient temperatures (20, 25 and 30 degrees C). Heat production, heart rate, abdominal temperature, shank skin temperature and respiration rate were measured before, during and after walking. 2. Heat production, heart rate and respiration rate increased abruptly after the start of walking and with increase in walking speed. At the start of walking, an abrupt increase in abdominal temperature occurred independently of walking speed and environmental temperature; then, as walking continued, abdominal temperature increased further with increasing walking speed and increasing environmental temperature. Shank skin temperature declined at the initiation of walking, then increased. 3. Heat production and heart rate recovered rapidly after walking, while shank skin temperature and respiration rate increased and then recovered, except at 30 degrees C. 4. A proportion, 17% to 35%, of the increased heat production was stored, increasing body temperature during walking. After walking, the stored heat was lost by means of panting until abdominal temperature recovered to 41 degrees C or shank skin temperature recovered to 37 degrees C. 5. These results suggest that the greatly-increased heat production attributable to forced walking leads to abrupt thermoregulatory physiological responses, and the heat stored in the body is actively dissipated by panting until abdominal temperature recovers to the pre-walking level. The chief mode of heat loss of birds changes with deep body temperature.

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Effects of treadmill exercise on the distribution of blood flow between the hindlimb muscles and abdominal viscera of the laying fowl

Cited by 9 publications

References 16 publications

Effect of acute heat exposure on blood flow and its distribution in the unrestrained laying fowl (Gallus domesticus)

Effect of acute heat exposure on blood flow and its distribution in the unrestrained laying fowl (Gallus domesticus)

Blood flow in guinea fowl Numida meleagris as an indicator of energy expenditure by individual muscles during walking and running

Effects of heat production attributable to forced walking on thermoregulatory physiological responses of chickens in a warm environment

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