Study On Determination Of Amount Of Bypass Starch In Common Used Feed And Its Absorption Rate In The Small Intestine For Ruminants

The experiments were conducted to study the amount of rumen bypass starch and the digestibility in the small intestine by both in situ and in vitro SIF as well as in vivo trails. The aim of this study is to gain the basic data for the absorbsent rumen bypass starch (BSEG) in MG in common-used feeds for sheep, which can offer BSEG; and to standardize the procedures (techniques) for the determination and to set up the database of MG values in common-used feeds. Part 1. Measurement of amount of rumen bypass starch and ruminal starch digestibility in common-used feeds. 9 Inner Mongolian semi-fine wool wethers fitted with permanent cannules at the rumen were used to investigate the amount of rumen bypass starch and its digestibility in(energy feed, protein feed, high quality and low quality forage) by in situ technique. The results showed that the corn and corn starch contained highest rumen bypass starch, while wild pea and corn stalks showed lowest, they were 417.85g/kg, 404.84 g/kg, 47.55 g/kg, 24.43g/kg, respectively. The amount of rumen bypass starch in other feeds were: wheat bran, 226.31 g/kg, soybean meal, 62.04g/kg ,flaxseed meal ,1 10.56 g/kg, cottonseed meal ,108.61 g/kg, alfalfa hay, 73.50 g/kg, grass hay, 50.87 g/kg. For the ruminal starch digestibility in tested feeds: soybean meal was highest (80.19%), corn was the lowest (50.47%), The digestibility value of other feeds were: wheat bran (61.70%), corn starch (60.95%), flaxseed meal (65.57%), cottonseed meal (61.01%), wild pea (70.40%), alfalfa hay (53.15%), grass hay (64.23%), corn stalks (73.65%), respectively. Part 2: Studies on small intestinal digestibility of rumen bypass starch in common-used feeds in those methods for measuring the digestibility of rumen bypass starch. in the small intestine. The studies included two trails. With corn as a test naaterial, trail one aimed for selecting the optimized cultural conditions for measuring digestibility of the starch in rumen undegraded feed residue by using SIF technique. Apart from to investigate the effect of SIF amount (0.2g, 0.3g, 0.4g, 0.5g, 0.6g) on DM and starch digestibilities ofrumen undegradated com (after l6h incubation) in small intestine, the effect ofincubation time (4h, 8h, 12h, l6h, 20h, 24h,) were also studied.The resultS indicated the optimized situations were as tbllows:0.45gSIF/0.56g rumenundegraded feed residue, McDougall buffer,pH=7.0,Ca2+ =680rm,39C, and optimizedincubation time was l2h.Trail two was held to stUdy the small intestinal digestibility of rumen bypass starch inenergy and protein feeds through SIF technique. The digestibility obtained as follows: com43.35%, Wheat bran l9.48%, com starch 57.79%, soybean meal, 67.33%, fiaxseed meal50. l9% and cottonseed meal 46.77%.Part 3: Study on dietary postruminal starch and its digestibility in the small intestine,and validating in vbo results.The studies included two trails.trail one was mainly focused on determinaion ofdigestible dietary starch. 9 Irmer Mongolian semi-fine wool wethers fitted withpermanent cannules at the rumen' proximal duodenum and terminal ileam were used todetermine dietny postruminal starch digestibility in the small intestine by SIF technique.The results for 3 dietary starch intestinal digestibilities were: 57.l3%, 55.l5%,55.10%.In vivo trail with Cf2O3 as markef, the dietary starch digestibilities in the rumen andsmall intestine were determined. The results obtained were' 3 dietary starch digestibility inthe rumen were: 59.53%, 55.20%, 52.34%;3 dietary rumen bypass starch were: l2l .57g/d,l08.59g/d and 89.70g/d; 3 dietary starch intestinal digestibility were: 7l.89%, 68.l5%and68.67%.