Journal ArticleDOI
Investigation of chromium, cerium and cobalt as markers in digesta. Rate of passage studies
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A new liquid marker, cobalt-ethylenediamine tetraacetic acid (EDTA), and two solid markers, chromium (Cr) and cerium (Ce) mordanted plant cell walls, were investigated and Co- EDTA was found to be comparable to Cr-EDTA.Abstract:
A new liquid marker, cobalt-ethylenediamine tetraacetic acid (EDTA), and two solid markers, chromium (Cr) and cerium (Ce) mordanted plant cell walls, were investigated. Synthesis and methods of analysis are described for the markers. The Cr- and Ce-cell wall complexes were tested for stability to EDTA, hydrochloric acid and rumen microorganisms. Plant cell walls were rendered indigestible by mordanting with Cr and 98% of the marker remained on the fibre after a simulated sequence (in vitro) of digestion. Ce-mordanted cell walls were 35% digestible in vitro using a rumen culture, and 56% of the marker could be washed off the remaining fibre. Treatment with EDTA removed all Ce and 15% of the Cr. Hydrochloric acid (0.01M) had a negligible effect on the removal of Cr from the cell walls, whereas 0.1M acid removed, on average, 10% of the marker. Losses of Cr from the mordant may be related to the quality of the preparation. Co-EDTA was found to be comparable to Cr-EDTA. The urinary excretion of Cr and Co was 2–3% in most animals except in rabbits, which excreted as much as 30% of the liquid markers in the urine.read more
Citations
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The estimation of protein degradability in the rumen from incubation measurements weighted according to rate of passage
E. R. Ørskov,I. McDonald +1 more
TL;DR: In this paper, a method for estimating the percentage of dietary protein that is degraded by microbial action in the rumen when protein supplement is added to a specified ration is proposed, where the potential degradability, p, is measured by incubating the supplement in artificial-fibre bags and is related to incubation time, t, by the equation p = a+b (1 − e -ct ).
Journal ArticleDOI
The use of internal markers to predict total digestibility and duodenal flow of nutrients in cattle given six different diets.
TL;DR: Three double-marker systems were used to calculate duodenal flows of organic matter, non-ammonia N (NAN), microbial N and NDF, and the most suitable was AIA, followed by INDF6, INDF41 and IADF41, and ADL was the least acceptable marker.
Journal ArticleDOI
Ruminant enteric methane mitigation: a review
TL;DR: In this paper, a review of strategies for reducing ruminant methane output are considered in relation to rumen ecology and biochemistry, animal breeding and management options at an animal, farm, or national level.
Journal ArticleDOI
Effects of an enzyme feed additive on extent of digestion and milk production of lactating dairy cows.
TL;DR: The results demonstrated the benefits of using a fibrolytic enzyme additive to enhance feed digestion and milk production by dairy cows.
Journal ArticleDOI
Excretion of purine derivatives by ruminants: effect of exogenous nucleic acid supply on purine derivative excretion by sheep.
TL;DR: In normally fed sheep, derivative excretion should relate to the microbial purines and, hence, microbial protein absorbed according to these models, and the changing proportions of allantoin and other derivatives in urine were probably due to changes in the relative importance of endogenous and exogenous purines as precursors.
References
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Journal ArticleDOI
Rate of passage of digesta in sheep. 4. Passage of marker through the alimentary tract and the biological relevance of rate-constants derived from the changes in concentration of marker in faeces.
W. L. Grovum,V. J. Williams +1 more
TL;DR: Results indicated that the changes in half-times were proportionately much greater in the caecum and proximal colon than in the reticulo-rumen, and the mean transit time of marker through the digestive tract also increased from 721 to 1345 min when the concentrate diet was given.
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Rate of passage of digesta in sheep. 3. Differential rates of passage of water and dry matter from the reticulo-rumen, abomasum and caecum and proximal colon.
W. L. Grovum,Vernon J. Williams +1 more
TL;DR: With increasing intakes of food, increases were observed along the entire large intestine in the amounts of wet digesta present, in the transit rates of digesta and in the rates of absorption of water.
Journal ArticleDOI
Factors Affecting the Utilization of Food by Dairy Cows
TL;DR: This paper is an account of the first stages in an investigation of factors that may influence the efficiency of the digestive processes in cows, and it is proposed to deal in subsequent publications with experiments in which some of these factors were investigated.
Journal ArticleDOI
The chromium-51 complex of ethylenediamine tetraacetic acid as a soluble rumen marker.
A. M. Downes,I. W. McDonald +1 more
TL;DR: HydCn (1961) has given a full mathematical treatment of the principles involved in the use of soluble markers to measure the rate of flow and volume of rumen fluid, and has indicated the inherent limitations of the method.
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Use of 103Ru-labelled tris (1,10-phenanthroline) ruthenium (II) chloride as a marker in digestion studies with sheep.
T.N. Tan,R.H. Weston,J.P. Hogan +2 more
TL;DR: It was concluded that the 103Ru complex could be a useful marker in a variety of digestion studies and may conveniently be used in digestion studies together with the 51Cr complex of ethylenediamine tetraacetic acid, a water soluble marker not adsorbed by the particulate fractions of digesta.