Veterinary Physiology Commons^™

The Effects Of Xanthine And Adenosine Analogs On Rat Pup Diaphragmatic Contractility, Liam C. Farrell

Masters Theses

Methylxanthines are commonly used in the treatment of respiratory disorders such as asthma, apnea of prematurity and Cheyne-Stokes respiration. Recently, certain methylxanthines have been found to potentiate the contraction of the diaphragm and increase contraction strength of the fatigued diaphragm. The mechanism of action of the methylxanthines is unknown. Three theories have been proposed but each has its supportive and negative points. One theory is that methylxanthines inhibit cyclic AMP phosphodiesterase (PDE) which facilitates contraction by increasing cyclic AMP levels in the cell. Another theory is that methylxanthines antagonize adenosine, thus blocking the adenosine-induced inhibition of contraction. The third theory …

Pregnancy Diagnosis Using Ultrasound, M A C Johns

Journal of the Department of Agriculture, Western Australia, Series 4

Few Western Australian ewe flocks are diagnosed for pregnancy despite the precence of high numbers of barren ewes. Surveys of farm flocks in the early 1970s recorded that between 14 and 29 per cent of ewes failed to lamb each year.

Techniques for diagnosing pregnant ewes have been available for many years, but ultrasonic devices and computer technology have made it possible for skilled operators to determine whether ewes are pregnant and more importantly, whether they have one, two or more foetuses.

Once the number of pregnant ewes is known farmers can use labour more efficiently. They can minimise the …

Reproductive Wastage In Sheep, R W. Kelly

Journal of the Department of Agriculture, Western Australia, Series 4

The average lambing performance of Western Australia's ewe flock fluctuates between 60 and 70 per cent. Although this level of performance and variation between years is important for the sheep industry, individual farmers are more concerned about performance of their own flocks.

Figure shows the range in lambing performances that exist between farms in this State in 1983-84. The seriously poor performance of many flocks is apparentm - 28 percent of farms had less than 60 per cent lambing. By contrast, 24 farms had performances better than 100 per cent. The reasons for the large differences between farms ( and …

Ovulation Rate Of Ewes : Role Of Energy And Protein, E Teleni, J. B. Rowe

Journal of the Department of Agriculture, Western Australia, Series 4

Western Australia's sheep farmers are familiar with the low ovulation rate of Merino ewes and how this limits the lambing performance of ewe flocks.

One way in which ovulation rate and therefore lambing percentage may be increased is to feed seed of sweet lupin (Lupinus augustifolius) to ewes at mating. However, Department of Agriculture research has found that these increases do not show up consistently, and that there is considerable variability between farms.

If improved nutrition is to be a useful way to increasing ovulation rate, the mechanism by which nutrition affects ovulation rate must first be understood. This article …

Some Factors Influencing The Availability Of Colostrum To Piglets, D. Fraser

Physiology Collection

Five experiments, involving the hand milking of 53 farrowing sows, examined aspects of colostrum yield during and soon after farrowing. The initial and abundant yield of colostrum from a teat (averaging 6 to 10 g/min) declined after several minutes of continuous milking. Thereafter, most colostrum was released in discrete ejections, possibly caused by discrete releases of oxytocin. Colostrum ejections varied greatly in their yield and duration, and were sometimes associated with the birth of a piglet, sounds of other sows nursing, or other factors.

Teats varied greatly in their yield. During the initial minutes of milking, the most anterior teats …

Protecting Off-Shears Sheep In Adverse Weather, T M. Ellis

Journal of the Department of Agriculture, Western Australia, Series 4

In January 2982 in the Narrogin-Darkan area of Western Australia, about 14,500 sheep up to 40 days off-shears died after a 48-hour period of heavy soaking rain that followed a thunderstorm three days previously. An estimated 100,000 sheep died throughout the South-West at the time.

P. G. Buckman - at the time Department of Agriculture District Veterinary Officer, Narrogin - surveyed 17 properties in the area. He found that losses in unshedded sheep 0 to 40 days off-shears ranged from 0 to 84 per cent of sheep on the property with an overall average of 27.9 per cent. Rainfall in …

Autoregulation Of Cortical Blood Flow In Response To Phenylephrine Induced Hypertension In The Normocapnic And Hypercapnic Cat, Forrest Ritland

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this research was to determine the degree of autoregulation of cortical blood flow in the cat, and to evaluate the usefulness of the heated thermocouple technique for measurement of local cortical blood flow. We determined the relationship between local flow and voltage output from our thermoelectric flow probe by in vitro experiments with an artificial kidney. We measured local cortical blood flow in 17 cats during episodes of phenylephrine-induced hypertension, under conditions of normocapnia and, in some cases, hypercapnia. Arterial blood pressure and voltage output from the flow probe thermocouples were recorded continuously with a Physiograph-six monitor. …

The Effects Of Insulin On Hepatic Glucocorticoid Receptor Content In The Diabetic Rat, Jeffrey John Yourick

Masters Theses

The streptozotocin-induced diabetic rat liver was analyzed for glucocorticoid receptor (GCR) content by a saturation and Scatchard analysis. A preliminary study was performed on the stabilization of the cytoplasmic GCR in a frozen cytosol preparation. The addition of 10% glycerol (V/V), 10 mM sodium molybdate, and 0.2 mg/ml trypsin inhibitor resulted in an approximate 20% sparing of GCR content upon freezing.

The hepatic GCR content of diabetic rats was significantly decreased from a control level of 0.1667 ± 0.0142 pmol/mg protein to 0.1094 ± 0.007 pmol/mg protein. Insulin replacement therapy to the diabetic rat dramatically increased the hepatic GCR content. …

The Effects Of Prostaglandin E2 On The Healing Processes Of Rat Perforated Tympanic Membranes, Diane Sue Saylor

Masters Theses

Prostaglandin E₂ (PGE₂) was topically administered to perforated rat tympanic membranes in an attempt to facilitate regrowth of the membranes. Every 24 hours for the first four postperforation days, two groups of tympanic membranes were processed and examined histologically for differences between PGE₂ treated and control animals.

At 24 hours postperforation granulocyte infiltration at the perforation site was greater in the test animals. By 48 hours blood clots were larger in PGE₂ treated animals. Finally, the epithelium was thinner in test animals than in control animals at 96 hours.

Slight tendencies for the test animals …

Blood Reservoir Function Of The Fetal Guinea Pig Liver, Gregory A. Roda, Raymond D. Gilbert, Gordon G. Power

Loma Linda University Electronic Theses, Dissertations & Projects

To determine of the fetal liver functions as a blood reservoir, we measured liver blood volume under normal conditions and after hemorrhage and volume loading. Nineteen pregnant guinea pig sows and 54 near-term fetuses were injected intravenously with ⁵¹Cr-labeled red cells while the fetuses remained in utero. Ninety seconds later a 0.5-1.0 g sample of liver was garroted with a sharp wire into a tared tube with minimal blood loss. A blood sample was taken to measure counts per ml of blood, the fetus killed and the remainder of the liver weighed. Blood volume of the liver and body …

Amputation Of Vibrissae In Show Dogs, Thomas E. Mcgill

International Journal for the Study of Animal Problems

No abstract provided.

Amputation Of Vibrissae In Show Dogs, Thomas E. Mcgill

Veterinary Science and Medicine Collection

Dogs of many different breeds competing in the show-ring are routinely subjected to amputation of the vibrissae, organs that are commonly and incorrectly called "whiskers." This procedure is thought to give the animal's head a cleaner look, which in turn supposedly increases its chances of winning. There are several tricks involved in "whisker trimming" since the animals can retract each vibrissae at least one-quarter inch. Furthermore, they often object strenuously to the operation.

Diagnosing Pregnancy In Sheep : The 'Scanopreg', R H. Wroth, M. J. Mccallum

Journal of the Department of Agriculture, Western Australia, Series 4

The "Scanopreg", an ultrasonic machine for diagnosing pregnancy in sheep, is effective as early as eight to nine weeks of pregnancy, and could therefore be a useful management tool.

An In Vitro Study Of The Effects Of 17Β Estradiol On A Possible Atherosclerotic-Causing Enzyme, Xanthine Oxidase, Peter E. Malo

Masters Theses

No abstract provided.

The Effect Of Prostaglandins And Aspirin On Insulin Release From Isolated Normal Rat Islets, Barbara Ann Hopps

Masters Theses

No abstract provided.

Pigs May Need More Protein, N W. Godfrey

Journal of the Department of Agriculture, Western Australia, Series 4

Results of trials indicate that meatmeal based rations of 18 to 20 per cent protein may improve carcase quality and give better returns.

The Pathophysiology Of Acute Venous Occlusion, Lewis H. Curd Jr.

Biological Sciences Theses & Dissertations

Large artery, pedal small vein, femoral vein and central venous pressures and extremity volume changes were recorded in mongrel dogs in which the hindlimb was perfused at a constant flow. Arterial, pedal venous and femoral venous blood gases were drawn and analyzed for measurements of arterio-venous O₂ and CO₂ differences. Paw and thigh resistances were calculated. Measurements were repeated following ligation of the iliac and femoral veins, alpha receptor blockade (dibenzyline), and dilation with Vasodilan. Results indicate that ligation of extremity veins results in an active ·increase in total limb resistance below the ligation, an increase in the …

Progesterone And Cortisol In The Hamster: Their Role In Parturition, As Well As The Growth And Lactogenesis Of The Mammary Glands, Anne Christine Flook

Masters Theses

No abstract provided.

Treflan And The Oxygen Consumption Of Green Sunfish (Lepomis Cyanellus), Barbara Jo Warner

Masters Theses

Oxygen consumption rates of 51 green sunfish (Lepomis cyanellus, Rafinesque) were monitored over five hours exposure to Treflan E.C. concentrations of 0, 0.32, 0.56, 1.0, and 2.0 ppm. There was a great variation in the responses of the fish at each concentration; and Student's t-tests revealed no significant differences. However, graphs of the mean hourly oxygen consumption rates showed certain trends. During the fifth hour of exposure, there appears to be an acclimation to the Treflan at concentrations of 0.32 and 0.56 ppm; but no such acclimation at the higher concentrations of 1.0 and 2.0 ppm. Hourly oxygen …

Metabolic Abnormalities In Liver And Pancreas Of A Diabetic (Toronto-Kk) Strain Of Mouse, Michael Clayton Appel

Masters Theses

No abstract provided.

The Effects Of Crowding On The Diurnal Ascorbic Acid Levels Of Albino Rats, Mary Jo Barr

Masters Theses

The adrenal physiology of the albino rat was studied through the measurement of adrenal ascorbic acid levels. A cyclic phenomenon was observed which follows the diel periodicity of the animal. Ascorbic acid values were found to be characteristically higher in males than in females. A similar difference was also seen in populations divided into young animals (body weight less than 175 grams) and old animals (body weight greater than 175 grams). Crowding, induced by manipulating the area of cage space per gram of body weight, was observed to be a definite stressor and caused the adrenal ascorbic acid levels to …

The Effects Of Acute Stress On Adrenal Ascorbic Acid Levels, Robert Joseph Collier

Masters Theses

The diurnal rhythm of adrenal ascorbic acid (DAR) displays an inverse relationship to the diurnal rhythm of circulating levels of plasma corticosteroids. Alloxan monohydrate, 175 mg/kg body weight was given subcutaneously to albino rats to determine the effect of the diabetic state on the DAR. A total of 200 female albino rats were divided into two study groups. Study Group I was composed of 150 animals divided into populations of 15, each including 3 controls. Study Group II was composed of populations of 5, each group containing all controls or all alloxinated rats. The populations of 15 were sacrificed at …

Sheep Fertility In Western Australia, R J. Lightfoot

Journal of the Department of Agriculture, Western Australia, Series 4

Why do one-quarter of the ewes that are joined in W.A. fail to lamb? Sheep and Wool Adviser Dr. R. J. Lightfoot analyses the eight stages in sheep reproduction, explaining the causes and possible prevention of infertility at each stage.

Pasture Legume Varieties And Ewe Fertility, T Marshall, H. E. Fels, H. G. Neil, R. C. Rossiter

Journal of the Department of Agriculture, Western Australia, Series 4

ALTHOUGH it was first thought that all varieties of subterranean clover would cause ewe infertility, research in the last 10 to 15 years has shown that varieties differ in potency.

The relative level of potency has also been shown to remain consistent for any one variety under normal conditions.

Prevent Worms In Cattle, G C De Chaneet

Journal of the Department of Agriculture, Western Australia, Series 4

PARASITIC gastro enteritis, caused by roundworms, is a common cause of economic loss in calves, yearlings and occasionally cows in south-western Australia. Losses could be prevented if stock owners realised the full effects of these parasites, and understood the causes of worm infestation.

Immunological And Reproductive Responses In The Male Rat Following Challenge With Homologous Or Autologous Sperm, James M. Andress

Masters Theses

No abstract provided.

Maintaining Ewe Bodyweight For A Late Mating, T Marshall

Journal of the Department of Agriculture, Western Australia, Series 4

DEPARTMENT OF AGRICULTURE experiments have indicated that the bodyweight of ewes at mating can have a large bearing on lambing performance.

It appears that for every 10 lb. increase in pre-mating bodyweight, an increase of some 3 to 6 per cent, lambs born could be expected, depending on the lambing time.

Later Mating Improves Lambing Results, R J. Suiter

Journal of the Department of Agriculture, Western Australia, Series 4

Ovulation studies in Western Australia have indicated that increased lambing percentages in crossbred and Merino ewes could be expected from mating in February-April rather than December- January.

Such increases have been demonstrated in time of lambing trials with crossbred ewes, but had not been seen in Merino flocks until recently.

This report summarises the results of time of lambing trials with Merinos carried out at the Merredin and Wongan Hills Research Stations between 1963 and 1969.

High Pre-Mating Liveweights Improve The Lambing Performance Of Merino Ewes, R J. Suiter

Journal of the Department of Agriculture, Western Australia, Series 4

Analysis of lambing trials with Merino ewes has shown a highly significant association between pre-mating liveweight and lambing performance.

With May-June lambing ewes there was a 2.9 per cent, lambing increase for every extra 10 lb. liveweight; for July-August- September lambing ewes there was a 6.9 per cent, increase for every 10 lb. liveweight increase.

With the May-June lambing there was a critical weight below which twinning was negligible.

Causes Of Low Lambing Percentages, Department Of Agriculture, Western Australia

Journal of the Department of Agriculture, Western Australia, Series 4

West Australian Merino flocks average about 70 per cent, lambs marked each year. Reasons for this low percentage are that as many as 30 per cent, of ewes do not lamb, twinning rates are low and from 10 to 25 per cent, of lambs born die.

Among the research projects by the Department of Agriculture's Sheep and Wool Branch have been a number directed at the various stages of reproduction in the ewe. These have given some important leads on the causes of low lambing percentages.

If you have marked less than 60 per cent, lambs in the past several …