Function In Sheep Research Articles

Some effects of anaesthesia, lateral recumbency and diversion of saliva on the rumen function of sheep

The effccts of anaesthesia, lateral recumbency, and the collection of saliva on the rate of contraction, pressure, total volatile fatty acid (V.F.A.) concentration, and pH of the rumen, and on the salivary secretion were investigated. Anaesthesia depressed the rate of contraction by the rumen, significantly increased the pressure of gas within the rumen as measured at the fistula, and reduced the rate of total salivary secretion by 66%. Anaesthesia had no effect on the concentration of nitrogen in the total mixed saliva, and its effect on the concentration of rumen total V.F.A. was inconclusive. During lateral recumbency a high concentration of rumen total V.F.A. was maintained. There was no change in the rate of contraction of the rumen, but there was a rise in the gas pressure measured at the rumen fistula and a decrease in the rate of total salivation. A significant increase was recorded in the total saliva nitrogen concentration. When total saliva was collected from the oesophageal fistulae of standing sheep, the pattern of total V.F.A. concentration within the rumen was altered. There was no change in the rate of contraction of the rumen or in the gas pressure at the rumen fistula. It was concluded that the diversion of 2 1. of saliva over a 5 hr period had little effect on the sheep provided the sodium loss was subsequently restored. It is suggested that care is needed in interpreting results obtained from sheep under anaesthesia or in lateral recumbency.

ACUTE TOXICITY OF NEPTUNIUM-237 AND ITS RELATIONSHIP TO LIVER FUNCTION IN SHEEP.

ACUTE TOXICITY OF NEPTUNIUM-237 AND ITS RELATIONSHIP TO LIVER FUNCTION IN SHEEP.

Studies on the relationship of saliva to rumen function of sheep on low feed intakes

Seven in vivo experiments are reported in which the effects of diverting alkaline mixed saliva from the actively fermenting contents of the rumen of anaesthetized and conscious sheep fed on a standard ration were studied for periods up to 6 hr. The absence of various quantities of saliva (225–1349 ml) was associated with profound alterations in the rumen environment: rumen liquor volatile fatty acid (V.F.A.) levels were consistently and substantially elevated, and rumen pH levels depressed. These changes in the rumen environment began about 40–60 min after saliva diversion commenced, and were sustained long after such values for the control animals had inflected towards fasting levels. Rumen movements were recorded in two experiments. Rumen movement was reduced, but not entirely suppressed, some 60 min after the minimal pH values obtained. It is suggested that this reduction in rumen movement was a consequence of depressed pH values. The rumen pH-rumen V.F.A. relationship was, in six such cases, altered but the strength of this relationship was not significantly changed. It was concluded that these effects on rumen pH-V.F.A. levels and relationship were due, directly or indirectly, to the changed buffering or osmotic regime, or both, of the saliva-depleted rumen liquor. Implications of these findings are discussed in the light of rumen physiology and the field use of oesophageally fistulated sheep.

Comparative indexes of thyroid function in sheep.

The effects of light and temperature on thyroid activity of sheep were assessed by four methods: thyroid secretion rate, zero time per cent uptake of I131, I131 output half-time, and measurement of the thyroid epithelial cell height. Increased ambient temperature inhibited thyroid activity as evaluated by all methods. Reduced temperatures consistently resulted in a depressed uptake of I131. I131 output half-time had no relationship with actual hormone secretion. Light alterations imposed the same trend on thyroid function when activity was assessed by secretion rate and cell height measurement. As evaluated by these two methods the lowest thyroid activity was observed at 12 hr of illumination per day and increased with both increasing and decreasing light beyond this 1:1 light-to-dark ratio. When the three isotopic measures of thyroid activity were correlated with the histological method the highest correlation was found between cell height and thyroid secretion.

A Study of the Passage of Fluid Through the Sheep’s Omasum

SUMMARY A study of the omasal function in sheep was made by means of an omasal cannula and the use of polyethylene glycol as a marker. It was observed that a part of the liquid leaving the reticulum passes straight through to the abomasum and another part is retained in the omasum. The rate of passage through the omasum was found to be 462 ml. per hour for an intake of 1000 g. dry matter. The pH and the chloride content of omasal liquid were higher than those of ruminal liquid. The carbon dioxide, sodium, potassium and ammonia contents were lower. The quantity of water absorbed from the omasum depended upon the molar concentration of the contents. Rapid absorption of carbon dioxide and sodium was observed. The absorption of potassium was much slower. The chloride concentration of the omasal contents increased when the initial concentration was below 140 mg./100 ml. In all other cases chloride was absorbed.

A Test for Vestibular Function in Sheep

A Test for Vestibular Function in Sheep

Glomerular and Tubular Functions in Sheep and Goats

In many species of experimental animals the true equality of the renal clearance of inulin and creatinine has not been demonstrated, and considerable evidence indicates some tubular participation i...

Renal function in sheep during normal and toxaemic pregnancies.

The Journal of PhysiologyVolume 131, Issue 2 p. 383-392 ArticleFree Access Renal function in sheep during normal and toxaemic pregnancies H. B. Parry, H. B. ParrySearch for more papers by this authorW. H. Taylor, W. H. TaylorSearch for more papers by this author H. B. Parry, H. B. ParrySearch for more papers by this authorW. H. Taylor, W. H. TaylorSearch for more papers by this author First published: 28 February 1956 https://doi.org/10.1113/jphysiol.1956.sp005469Citations: 13AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume131, Issue2February 28, 1956Pages 383-392 RelatedInformation