Section A. Physiology. Part 1. The Physiology of the rumen. Part 2. Rumen microbiology

Kay, R. N. B.; Hobson, P. N.

doi:10.1017/s0022029900011468

Cited by 35 publications

(8 citation statements)

References 266 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The ingestion of saline water (1-3 yo NaCl) by sheep resulted in significant increases in osmotic pressure within the rumen, the increases being greater when the diet consisted of ground pelleted lucerne than when it consisted of chaffed hay. Unlike the control sheep drinking fresh water in which the rumen contents, in agreement with the reports of Kay (1963), von Engelhardt (1963 and Warner & Stacy (1965), remained hypotonic compared with blood plasma, the rumen osmolality of the sheep drinking…”

Section: Discussionsupporting

confidence: 82%

Changes in intraruminal function of sheep when drinking saline water

Walker

Forrest

1972

Br J Nutr

View full text Add to dashboard Cite

I. A study was made of the changes in electrolyte concentrations and ruminal function which resulted from the provision of 1.3 7; sodium chloride solutions instead of fresh water to sheep consuming roughage rations in chaffed and in ground pelleted forms.2. Significantly higher osmotic pressures were observed in the rumen fluid of the sheep drinking saline water, the change being especially marked when the ration was ground and pelleted.3. Of the individual electrolytes measured, chloride showed a larger rise in concentration than did sodium plus potassium and it appeared that the sodium and chloride ions in the ingested saline water were differentially removed from the rumen. 5. Based upon measurements of deoxyribonucleic acid and polysaccharide, there appeared to be a tendency for the total microbial populations in the rumens of sheep drinking 1.3 yo NaCl solution to be smaller than for the sheep drinking fresh water. 6. The total metabolic activity of the rumen flora, measured calorimetrically, was not appreciably changed when saline water was drunk and the chaffed ration eaten, but was significantly reduced when the ration was ground and pelleted.7 . Adaptation of the rumen microflora to high concentrations of NaCl was demonstrated in animals accustomed to drinking 1'3 76 NaCl solution.T h e tolerance of sheep for ingested drinking-water containing relatively high concentrations of dissolved salts is remarkably good (Peirce, 1957). The animals will survive for periods of I 5 months or more drinking 1-3 yo sodium chloride solution or mixtures of sodium chloride with other salts in solution making a total solute concentration of about 1.3 % (Peirce, 1963). Productivity, in terms of body-weight and wool production, is unaffected by prolonged drinking of such salt solutions.Studies by Potter (1961Potter ( , 1963Potter ( , 1966Potter ( , 1968 have shown that there is an adaptive mechanism involving kidney function which allows the sheep to deal with large quantities of ingested or infused salt, and it has been suggested that this mechanism may be related to conditions within the rumen. Adaptation of the rumen flora was postulated by Peirce (1957) to account for the increased food consumption which often accompanied salt-water ingestion in sheep; and the absorption of sodium is stimulated by hypertonic conditions in the rumen according to Stacy & Warner (1966). von Engelhardt (1969) Since the rumen receives fluid almost immediately after it is ingested, it might be expected that changes in rumen function induced by salt-water intake could be important in the total response of the sheep to salt-water consumption. E X P E R I M E N T A L AnimalsSix Merino ewes, with permanent rumen fistulas, were used throughout the experiments. Three animals had been accustomed to drinking 1.3 % sodium chloride for a period of 6-12 months. Whilst on experiment the animals were confined to metabolism cages. RationsTwo rations were given, one consisting of 75 yo chaffed wheaten hay plus 25 9/ o chaffed luccrne hay, the other being...

show abstract

Section: Discussionsupporting

confidence: 82%

Changes in intraruminal function of sheep when drinking saline water

Walker

Forrest

1972

Br J Nutr

View full text Add to dashboard Cite

show abstract

“…Ammonia is an important metabolite in the rumen, where it is formed mainly from the deamination of amino acids released by proteolysis of ingested protein and by the hydrolysis of blood urea which enters the rumen in saliva or by passage across the rumen wall (Kay & Hobson, 1963). Rumen ammonia which is not utilized by the rumen microflora for synthesis of microbial protein is absorbed and transported to the liver for conversion into urea.…”

mentioning

confidence: 99%

Ammonia in the large intestine of herbivores

Hecker

1971

Br J Nutr

View full text Add to dashboard Cite

1. The object was toinvestigate the importance of urea a source of ammonia in the large intestine of herbivores. Urea was present in small intestinal contents of slaughtered horses in concentrations similar to those in blood but, in the small intestine of salughtered sheep, the urea was less than in blooc.2. There was little ammonia in small intestinal contents of slaughtered horses but consider-able ammonia was present in small intestinal contents of slaughtered sheep. The ammonia in small intestinal contents of the slaughtered sheep was probably formed from urea, as ileal con-tents taken from a sheep with an ileal cannula contained considerable urea and little ammonia.3. The ammonia concentration in caecal contents of sheep was related to the concentration of urea in blood except when ileal contents were prevented from entering the caecum.4. Ileal digesta of sheep contained more free amino nitrogen than did caecal digesta.5. Ammonia was absorbed more rapidly than water from the caecum of sheep. The rate of absorption was related to the concentration of ammonia in the caecum.

show abstract

“…Cette origine microbienne des acides gras ramifiés du lait de vache est également admise par Garton (1963) et par Kay et Hobson (1963), dans deux études récentes se rapportant à l'origine des acides gras du lait.…”

Section: -Discussionunclassified

Étude comparée des acides gras ramifiés des aliments et du lait chez la vache

Kuzdzal-Savoie¹

1965

Lait

View full text Add to dashboard Cite

Sommaire L'expérience a porté sur un troupeau expérimental de 7 vaches laitières. Les acides ramifiés des lipides alimentaires et du lait ont été dosés par chromatographie en phase gazeuse. On a ensuite calculé les quantités d'acides gras ramifiés ingérés et sécrétés au cours d'une période de 24 heures. Il n'existe qu'une faible proportion d'acides gras ramifiés dans les lipides des aliments distribués aux vaches laitières (inférieure à 1 p. 100 des acides gras totaux). Par contre, les acides ramifiés représentent une fraction toujours notable des acides gras du lait, voisine de 2 à 3 p. 100 des acides totaux. Les acides ramifiés à 15 et 17 atomes de carbone sont prépondérants. Ceci appuie l'hypothèse de l'origine microbienne, d'une partie au moins, des acides gras ramifiés du lait. r.-Introduction Les acides gras ramifiés se distinguent des acides à chaîne droite par la présence d'un groupe méthyle fixé sur le pénultième ou l'antépénultième carbone ou par la présence de plusieurs groupes méthyle répartis le long de la chaîne. Ces acides sont toujours présents dans la matière grasse du lait (

show abstract

Section A. Physiology. Part 1. The Physiology of the rumen. Part 2. Rumen microbiology

Cited by 35 publications

References 266 publications

Changes in intraruminal function of sheep when drinking saline water

Changes in intraruminal function of sheep when drinking saline water

Ammonia in the large intestine of herbivores

Étude comparée des acides gras ramifiés des aliments et du lait chez la vache

Contact Info

Product

Resources

About