A comparison of particulate markers for the estimation of digesta flow from the abomasum of sheep offered chopped oaten hay

Abstract

Five sheep with simple cannulae in the rumen and abomasum were given a diet of chopped oaten hay at 95-98% of ad libitum intake from continuously moving belts. Flows of digesta from the abomasum were estimated by a double marker method by reference to 51Cr-EDTA as the fluid marker, and either 103Ru-P, lignin, or acid insoluble ash (AIA) as the particulate marker. Estimates were also made by reference to lignin as a single marker. Estimates of the weight of digesta leaving the abomasum daily were unaffected by the choice of particulate marker when used with 51Cr-EDTA, but were 25% lower when lignin was used alone. The estimated flows of dry matter and acid detergent fibre (ADF) were dependent upon the choice of markers. Compared with estimates of ADF flow given by 51Cr-EDTA and lignin, estimates given by AIA were lower (-24.6%) and those given by 103Ru-P were higher (+26.2%). Lignin alone gave estimates 1.6% higher. Observations on the distribution of 103Ru-P in digesta dry matter indicated a markedly higher concentration on fine than on large particles. It is concluded that lignin may be preferable to 103Ru-P as a particulate marker when certain coarsely chopped roughages are given to sheep, and when samples of digesta from the abomasum are obtained through a simple cannula.

Whole-tract digesta kinetics and comparison of techniques for the estimation of fecal output in steers fed coastal bermudagrass hay at four levels of intake2

“…Lindberg (1988) indicated that ruminal outflow of small particles is related to ruminal outflow of water. Egan and Doyle (1984) demonstrated with sheep that very small particles flowed at a rate close to that of the fluids, and that the PPR from the reticulorumen increased as particle size decreased. Because of entrapment in the reticuloruminal raft, even the finest particles flowed from the reticulorumen more slowly than the fluid fraction; a small proportion, however, seemed to flow with the fluid fraction (Faichney, 1986).…”

Effects of carrier matrix and dosing frequency on digestive kinetics of even‐chain alkanes and implications on herbage intake and rate of passage studies

“…This could explain the shorter TMRT observed for even-chain alkanes adsorbed into cellulose powder (C 24 and C 28 alkanes) in comparison with the other matrices. Nevertheless, even the very small particles have a longer retention time than fluid, probably owing to sieving effects of the reticuloruminal mass, 24 explaining the slightly longer TT and TMRT for both C 24 and C 28 alkanes in comparison with those for Co-EDTA, a liquid phase marker. The different retention times (TMRT ) among markers have to be mainly attributed to the different TT values estimated, because no differences were observed in the values of k 1 .…”

“…Co-EDTA, prepared following the procedure of Udén et al, 17 was dissolved in distilled water (7.5 g of Co-EDTA in 200 ml of water), and 30 ml of the solution was administered to each animal. Total amounts of faeces voided during each time interval were collected in buckets at 6,9,12,16,20,24,28,32,38,44,53,65,77,89,114,137 and 161 h post-dosing. At each sampling time the bulk faecal output of each animal was weighed, mixed thoroughly and sampled.…”

Kinetics of nitrogen transfer across the rumen wall of sheep given a low-protein roughage

“…The double-marker method requires that the markers used be distributed evenly throughout their respective phases (Faichney, 1975 a). However, lo3Ru-P is not evenly distributed throughout the particulate matter (Faichney,(1 982) so that reconstitution factors depending on this marker may not adequately correct for relatively large sampling errors (Faichney, 1982;Egan & Doyle, 1984). Accordingly, where reconstitution factors for abomasal digesta were greater than 0.2-0.3, the faecal output of ADL was compared with its abomasal flow assuming there was no post-rumen disappearance of ADL (Fahey & Jung, 1983).…”