The effect of sucrose supplementation on kinetics of nitrogen, ruminal propionate and plasma glucose in sheep

Abstract

S U M M A R YThe effects of dietary sucrose on the metabolic rate of plasma glucose and ruminal propionate as well as the change in nitrogen kinetics were examined in four mature wethers fitted with rumen fistulas in Tsukuba, Japan in 1990. Wethers were fed at 12 equal intervals daily on crushed lucerne hay cubes (1233 g DM/day), with or without 204 g/day of sucrose. Plasma urea and glucose kinetics were determined following a single intravenous injection of [ I5 N]urea and [U-13 C]glucose respectively; and the kinetics of ruminal ammonia and propionate were determined following a single intraruminal injection of [ 15 N]ammonium chloride and [2-13 C]sodium propionate respectively. Following supplementation of sucrose to the diet, nitrogen retention was increased (P < 005) with a decrease in plasma urea concentration (P < 005) and urinary urea excretion (P < 005). Sucrose supplementation decreased (P < 005) the concentration and irreversible loss rate of ruminal ammonia. Urinary allantoin excretion did not change with sucrose treatment, but the flow rate of non-ammonia-nitrogen from the rumen was increased (P < 0-05). The transfer rate of ruminal ammonia to plasma urea was also decreased (P < 001), whilst the transfer rate of plasma urea to ruminal ammonia was increased (P < 005) by dietary sucrose. Sucrose supplementation resulted in a higher concentration of propionate and butyrate (P < 005) in the rumen with no significant change in acetate or pH. The concentration of plasma glucose did not change with sucrose treatment, but the concentration of insulin, pool size (P < 0-05) and the irreversible loss rate of glucose (P < 001) were increased, reflecting the increase in the production rate of ruminal propionate (P < 005). It was concluded that the supplementation of sucrose affected the metabolism of urea and glucose in plasma via a change in ruminal production rate of ammonia and propionate, respectively.

In vitro investigation into the nutritive value of Lolium perenne bred for an elevated concentration of water-soluble carbohydrate and the added effect of sample processing: freeze-dried and ground vs. frozen and thawed

“…The lower ammonia concentrations encountered with a substrate higher in WSC, indirectly support the findings of Sutoh et al [13]. They found that when sheep were fed a Lucerne hay diet supplemented with sucrose, a decrease in ruminal ammonia concentration occurred compared to hay alone, accompanied by an increase in nitrogen retention and a decrease in plasma urea and urinary nitrogen excretion.…”

Effect of humic acid on fermentation and ciliate protozoan population in rumen fluid of sheep in vitro

“…13 Similar to the reduced ammonia N concentration in the present experiment, feeding of a readily available energy source, either as a supplement or as a high sugar diet also decreased the rumen ammonia N concentration. 38,39 This is due to a higher utilisation of ammonia N for microbial protein synthesis, or to reduction in the use of amino acids as an energy source by micro-organisms when energy is readily available. 40,41 The molar proportion of propionate was reduced, the proportion of n-butyrate was increased, and the proportion of acetate was not different between HC-control and HC-H60B in RUSITEC fermentation.…”

Correlation between modern plant δ15N values and activity areas of Medieval Norse farms

“…This is perhaps most evident in the results for the spatially limited and spatially defined features, and we begin with these. Cattle and sheep dung is enriched w3& above the feed (Kerley and Jarvis, 1996;Sutoh et al, 1996). One can use the measured d 15 N average for the natural samples (1.1&) and this amount of enrichment to predict that the sheep, and presumably goat dung, would have been w4&.…”