|Title||Over de osmotische waarde en de gehalten aan enige opgeloste bestanddelen van de darminhoud en de mest bij het rund, in verband gebracht met de resorptie der mineralen|
|Author(s)||Weerden, E.J. van|
|Source||University. Promotor(en): E. Brouwer. - Wageningen : Veenman - 99|
|Publication type||Dissertation, internally prepared|
|Keyword(s)||rundvee - diervoeding - cattle - animal nutrition|
|Abstract||Osmotic pressure of the contents from various parts of the gut was related to the concentrations of Ca, Mg, NH 4+, Na, K, Cl, total carbonic acid, inorganic phosphate, sulphate and steam-volatile fatty acids in press-juice of gut contents and faeces of 16 cows.
Abomasal contents were slightly hypotonic to the blood. The most important osmotically-active elements were Na and Cl.
In the upper ileum the chyme was strongly hypertonic largely through organic non-electrolytes but also Na and Cl.
Distally in the small intestine osmotic pressure gradually decreased and in the caecum they were almost isotonic with the blood, largely through Na and, to a lesser extent, K and NH 4+.
Strong selective absorption of Na against a concentration gradient caused the hypotony of colonic contents and faeces. Re-absorption from the large intestine was important in the Na metabolism of the cow.