Evaluation of certain properties of radiocerium as an indigestible marker

Huston, J. E.; Ellis, W. C.

doi:10.1021/jf60156a006

Cited by 24 publications

(4 citation statements)

References 6 publications

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“…On the first day of an experiment 'background-Mg' was determined in samples of rumen and duodenal contents which were collected at intervals from 08.00 hours over a period of 24 h. On the second day the stall-fed steers were fed at 08.00 hours, rumen and duodenal samples taken at 08.45 hours and a mixture containing Mg and markers infused into the rumen at 09.00 hours. The mixture contained, in 0.24-0.50 kg water, 3'5-7 g Mg (as magnesium chloride), 30-50 g polyethylene glycol (PEG) (molecular weight 4000) to function as a water soluble marker and 50-100 pCi 144Ce (as a tracer dose of cerous chloride in I M-hydrochloric acid ; Radiochemical Centre, Amersham) to function as a solid-phase marker (Huston & Ellis, 1968). The effectiveness of 144Ce as a solid-phase marker was checked by adding 50 pCi 14*CeC1, to the ruinen of a steer consuming diet B and examining the distribution of radioactivity in rumen contents after I h. Approximately 90-95 % was associated with the solid matter.…”

Section: Materials a N D Methodsmentioning

confidence: 99%

Absorption of magnesium by the young steer

Horn¹,

Smith²

1978

Br J Nutr

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I. Steers with m e n and simple duodenal cannulas were allowed to graze pasture or were given diets of dried grass or flaked maize with or without hay. For an experiment a solution or suspension of magnesium chloride, polyethylene glycol (molecular weight 4000) and either la4Ce (as cerous chloride) or chromic oxide was added to the rumen with a morning feed. Conditions in the rumen were sometimes modified by adding sodium chloride or hydrochloric acid.2. Changes in magnesium: marker in samples of strained rumen contents with time interval after adding the dose were due partly to changes in Mg distribution between different phases. Results indicated, but not unequivocably, that negligible amounts of Mg were absorbed in the first few hours.3. Relative recoveries of Mg and markers at the duodenum indicated that proportions of Mg intake absorbed (net) varied from approximately zero for pasture to 02-05 for flaked maize. Significant correlations between absorption efficiency and sodium: potassium in rumen contents (positive) and rumen pH (negative) were observed.4. Steers with simple duodenal and re-entrant ileal cannulas were given a diet of flaked maize and hay supplemented with different amounts of magnesium oxide. Little net change in Mg relative to an unabsorbed marker was found between these sites even for a diet containing an Mg supplement of 8 g/kg dry matter.

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Section: Materials a N D Methodsmentioning

confidence: 99%

Absorption of magnesium by the young steer

Horn¹,

Smith²

1978

Br J Nutr

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“…Markers The marker used for the water phase of digesta was 51Cr EDTA (Downes & McDonald, 1964) and 144Ce-144Pr (la4Pr) was used as the marker for the particulate matter (Miller, Perry, Chandler & Cragle, 1967;Ellis & Huston, 1968;Huston & Ellis, 1968). Table 1, The schedule for each experimental period in an experiment in which jive sheep were studied in a 5 x 5 Latin square design…”

Section: M and Ash Contents Of Food And Faecesmentioning

confidence: 99%

Rate of passage of digesta in sheep

1977

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1.Five sheep were given 400,625, 850, 1075 and 1300 g lucerne chaffid according to a 5 x 5 Latin square design to perturbate a mathematical model describing the rate of passage of digesta in terms of rate constants for the reticulo-rumen (k,) and caecum and proximal colon (ka), and a transit time (n) for the intestines. These values were obtained from the concentration curves of W r EDTA and 1r4Ce-14rPr (lO4Pr) excretion in faeces for comparison with similar measurements obtained directly.2. The retention times of markers in the reticulo-rumen, caecum and proximal colon and intestines all decreased by approximately 50 % as intakes were increased from 400 to 1300 g/d. For both markers, the direct and indirect measures of half-time in the reticula-rumen were essentially identical. The predicted (indirect) values for half times in the caecum and proximal colon were smaller than the direct values (P < 0405) but the correlations between them were significant (P < 0.01) for "Cr EDTA (r 066) and l4Vr (r 0.78). The direct measures of transit time were smaller (P < 0.025) by 5-10 a/. than the predicted values but correlations between them were significant (P < 0.01) for W r EDTA (r 0.91) and for lrrPr (r 0.93). Thus the model predicted the changes produced in the rate of passage of digesta and its usefulness and limitations are discussed. 3. With lr4Pr ,k, for the reticulo-rumen and TAka for the caecum and proximal colon were both positively correlated (P < 0-025) with the organic matter digestibilities. Ttk, decreased at half the rate of Ttkl with increasing intakes. This wcluld have favoured compensatory digestion in the large intestine.This experiment in pertubatian analysis was designed to evaluate further a mathematical model of digesta passage thiough the alimentary tract of the sheep. Grovum & Williams (1973~) showed that the rate of passage of digesta in sheep given either 800 g lucerne chaff or diets consisting of wheat and lucerne chaff could be described with an equation having as independent variables: the transit time of marker through the intestinal tract (TT), the half-time of marker in the reticulo-rumen (Tjk,) and the half-time of marker pertaining mainly to the caecum and proximal colon (Tik,).In the experiment now reported, the rate of passage of digesta through the gut was increased by increasing the level of food intake and values of TT, Tik,, and Tik, were compared with corresponding measurements made more directly. The biological relevance of these values for rate of passage was studied by relating them to the apparent digestibility of the food, the concentrations of volatile fatty acids (VFA) in the reticulo-rumen and the water content of the faeces. E X P E R I M E N T A L SheepThree Merino wethers (castrated males) (sheep nos. 1, 2 and 3) and two ewes (sheep nos. 4 and 5 ) with permanent rumen (Hecker, 1969) and abomasal (Jarrett, 1948) fistulas were 15 N U T 38

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“…To check that this technique was satisfactory even though PEG and 15N moved at different rates the relative recoveries of PEG and the slowly-moving particulate marker 144Ce (Huston & Ellis, 1968) were also examined.…”

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confidence: 99%

Factors affecting the capture of dietary nitrogen by micro-organisms in the forestomachs of the young steer. Experiments with [¹⁵N]urea

Salter¹,

Smith²,

Hewitt³

1983

Br J Nutr

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1. For a period of at least 2 weeks before an experimental collection each of four young steers received total daily intakes consisting of approximately (g/kg) 600 straw and 400 concentrates with the nitrogen provided mainly as urea and in which the main energy source was starch (tapioca) for diet 1 and glucose for diet 2. Concentrates were given twice daily at about 09.00 and 17.00 hours, straw at 17.00 hours only. The value for the ratio, rumen-degradable N: metabolisable energy (g/MJ) in the daily intake was estimated to be approximately 1.2. 2.On the day that an experimental collection was to be made the urea normally given in the feed at 09.00 hours was labelled with 15N. This urea and sometimes the appropriate energy source were added either as a single dose (SD) at 09.00 hours or in three equally-divided doses (DD) at 09.00, 11.00 and 13.00 hours. Treatments, given in a Latin-square design, were: (A), starch (SD) + urea (SD); (B), starch (SD)+urea (DD); (C), glucose (SD) +urea (DD); (D), glucose (DD)+urea (DD). Doses of polyethylene glycol (PEG) and 144Ce (as cerous chloride) were given as markers with the urea, 3. After these doses were given, samples of abomasal and duodenal digesta were taken periodically for 72 h. It appeared that virtually all the PEG had left the rumen by this time and mean recovery of 144Ce relative to PEG was approximately 90%. From recoveries of non-ammoniaJ5N (microbial I5N) at the abomasum, estimated relative to PEG, values for mean fractional efficiencies of conversion of urea-N to microbial-N were calculated to be 0.59, 0.59, 0.40 and 0.41 for treatments A, B, C and D respectively. Values for treatments A and B were significantly greater than those for treatments C and D but no other differences were significant. Examination of duodenal samples led to similar conclusions.4. It wasconcluded that starch wasamoresuitableenergysource thanglucose formaximalcapture ofammonia-N for microbial synthesis but that spreading the urea and glucose doses in an attempt to match energy and ammonia release rates had no significant effect on capture efficiency.

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Evaluation of certain properties of radiocerium as an indigestible marker

Cited by 24 publications

References 6 publications

Absorption of magnesium by the young steer

Absorption of magnesium by the young steer

Rate of passage of digesta in sheep

Factors affecting the capture of dietary nitrogen by micro-organisms in the forestomachs of the young steer. Experiments with [¹⁵N]urea

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Evaluation of certain properties of radiocerium as an indigestible marker

Cited by 24 publications

References 6 publications

Absorption of magnesium by the young steer

Absorption of magnesium by the young steer

Rate of passage of digesta in sheep

Factors affecting the capture of dietary nitrogen by micro-organisms in the forestomachs of the young steer. Experiments with [15N]urea

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Product

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Factors affecting the capture of dietary nitrogen by micro-organisms in the forestomachs of the young steer. Experiments with [¹⁵N]urea