Catalogo Articoli (Spogli Riviste)

OPAC HELP

Titolo:
OSMOTIC-PRESSURE, WATER KINETICS AND VOLATILE FATTY-ACID ABSORPTION IN THE RUMEN OF SHEEP SUSTAINED BY INTRAGASTRIC INFUSIONS
Autore:
LOPEZ YS; HOVELL FDD; MACLEOD NA;
Indirizzi:
UNIV LEON,DEPT PROD ANIM E-24071 LEON SPAIN ROWETT RES INST BUCKSBURN AB2 9SB ABERDEEN SCOTLAND
Titolo Testata:
British Journal of Nutrition
fascicolo: 2, volume: 71, anno: 1994,
pagine: 153 - 168
SICI:
0007-1145(1994)71:2<153:OWKAVF>2.0.ZU;2-I
Fonte:
ISI
Lingua:
ENG
Soggetto:
MINERAL SALTS; FLOW; FERMENTATION; PASSAGE; DIGESTA; VOLUME; SODIUM; BODY; WALL; DIET;
Keywords:
OSMOTIC PRESSURE; RUMEN; LIQUID OUTFLOW; WATER ABSORPTION; VFA ABSORPTION; SHEEP;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
35
Recensione:
Indirizzi per estratti:
Citazione:
Y.S. Lopez et al., "OSMOTIC-PRESSURE, WATER KINETICS AND VOLATILE FATTY-ACID ABSORPTION IN THE RUMEN OF SHEEP SUSTAINED BY INTRAGASTRIC INFUSIONS", British Journal of Nutrition, 71(2), 1994, pp. 153-168

Abstract

The effects of changing rumen osmotic pressure (OF) upon water kinetics and volatile fatty acid (VFA) absorption in the rumen of sheep werestudied in two 4 x 4 Latin square experiments, each using four lambs with a rumen cannula and an abomasal catheter. In both experiments thelambs were sustained by the intragastric infusion of all nutrients (VFA, Ca, P, Mg and a buffer solution into the rumen, and casein, vitamins and trace elements into the abomasum). On experimental days, which were at least 1 week apart, drinking water and the casein infusion were withdrawn, and the ruminal OP was changed and held constant for 9.5 h, by incorporating NaCl at different concentrations in the buffer solution being infused. In Expt 1 the target OP values were 300, 340, 380and 420 mosmol/kg, and in Expt 2 were 261 (no saline addition), 350, 420 and 490 mosmol/kg. Using soluble non-absorbable markers (PEG in continuous infusion and Cr-EDTA injected in pulse doses) rumen volume, liquid outflow rates, apparent water absorption through the rumen wall and VFA absorption rates were estimated at six sampling times corresponding to the 1.5 h intervals during the last 7.5 h following the change in rumen OP. Liquid outflow rate (F; ml/h) showed a significant and positive linear relationship with the rumen OP (mosmol/kg), resulting in the equation F = 1.24 OP (SE 0.096) -36.5 (SE 36.6) (r(2) 0.96). Similarly, water absorption rate (W; ml/h) was significantly affected byrumen OP, and this relationship was given by W = 395 (SE 399)-1.16 OP(SE 0.105) (r(2) 0.95), which means that for an OP of 341 mosmol/kg the net movement of water across the rumen wall would be zero, and either a net efflux or a net influx of water would be observed with lower or higher OP respectively. In Expt 2 there was a significant linear effect of OP on rumen volume (P < 0.01), with higher OP being associatedwith increases in rumen liquid contents of about 10-20 %. As rumen OPwas increased there was also a decline in the absorption rate of VFA (from 232 mmol VFA/h for OP 350 to 191 mmol/h for OP 490 mosmol/kg), resulting in the accumulation of VFA (especially acetate) in the rumen and a consequent fall in rumen pH. Rumen OP seems to be important in defining water movement across the rumen wall and, hence, partitioning between absorption and outflow.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 25/01/21 alle ore 18:23:27