Effect of Wheat and High-Moisture Sorghum Grain Fed Singly and in Combination on Ruminal Fermentation, Solid and Liquid Flow, Site and Extent of Digestion and Feeding Performance of Cattle

Abstract

Two experiments were conducted to determine how varying the proportion of wheat (W) and high-moisture sorghum grain (SG) in 80% grain dies would affect ruminal fermentation, liquid and solid flow, site and extent of digestion (Exp. 1) and feeding performance of cattle (Exp. 2). In Exp. 1, three ruminal, duodenal and ileal cannulated steers (average weight 295 kg), fed at 1.54% of body weight, were used in a six-period crossover design. Treatments were: W, 50W:50SG (W:SG) and SG. Increasing wheat level decreased ruminal pH, molar proportion of acetate, and acetate:propionate ratio (P less than .05) and increased (P less than .05) L-lactate concentration, molar proportions of propionate and valerate and total volatile fatty acid concentration. Ruminal liquid dilution and outflow rates were faster (P less than .05) and retention time was shorter (P less than .05) for the W diet. Duodenal and ileal liquid flow increased (P less than .05), and solid flow decreased (P less than .05), as dietary level of wheat increased. Apparent ruminal digestion (% of intake) of dry matter (DM) and organic matter (OM) was greater (P less than .01) with the wheat-containing diets. Intestinal DM and OM digestion (percent of intake) was higher (P less than .05) with the SG and W:SG diets. Ruminal, small intestine, large intestine and total tract starch digestion (percent of intake) was 93.5, 5.6, .7, 99.8, 71.5, 20.4, 5.7, 97.6; and 48.0, 32.5, 10.5, 91.0 with the W, W:SG and SG diets, respectively. In Exp. 2, group-fed (24 pens) steers (avg initial weight 341 kg) were fed ad libitum once daily for 121 d. Treatments were: W, 67W:33SG, 33W:67SG and SG. Rates of gain (kg/d) with the W (1.32), 67W:37SG (1.33) and 33W:67SG (1.30) diets were similar (P greater than .05), but faster (P less than .05) than those with the SG diet (1.16). Feed intake was lower (P less than .01) with the W and 67W:33SG diets, but the wheat-containing diets were utilized more efficiently (P less than .01). Increasing the proportion of wheat in sorghum grain feedlot diets improved cattle performance by optimizing ruminal and post-ruminal digestion.

In situ starch and crude protein degradation in the rumen and in vitro gas production kinetics of wheat genotypes

“…Secondary ST particle losses cannot occur in the GP technique, which is a major difference between the in situ and GP methods (Cone et al., ). Although the ST degradation rates were potentially overestimated in this study, the mean value (91%) and variance (87–94%) of EDST8 were in accordance with in vivo values ( n = 13; mean = 90%; minimum = 83%; maximum = 95%) of ruminal ST degradation from wheat grains in the literature (Axe et al., ; Zinn, ; Lebzien et al., ; Philippeau et al., ; Matthé et al., ; Ueda et al., ; Hindle et al., ; Larsen et al., ; Šimko et al., ). Therefore, we conclude that overestimation of the ST degradation rates in situ only marginally influences the calculation of the EDST from wheat grains.…”

Effects of rumen-escape starch and coarseness of ingredients in pelleted concentrates on performance and rumen wall characteristics of rosé veal calves

“…'Indicator of starch digestibility' The 'indicator of starch digestibility' of Control and Coarse was similar (98.6%) ( Table 2) and is in agreement with starch digestibility values reported by others (Galyean et al, 1979;Axe et al, 1987;Philippeau et al, 1999) and is expected, since the seed coat has been cracked in the Coarse concentrate. Increased particle sizes of the Coarse concentrate may increase the selective retention time and lower the fractional rumen outflow rate of potential digestible Concentrate type and rumen wall characteristics of bull calves starch, which will cause increased microbial fermentation of starch (Van Soest, 1994).…”

“…Corn and sorghum will generally have a slower starch digestion in the rumen (i.e., a higher rumen by-pass) compared with wheat and barley (Axe et al, 1987;Philippeau et al, 1999;Larsen et al, 2009). A higher amount of rumenescape starch will increase rumen pH (Owens et al, 1998).…”

Small intestinal starch digestion in steers: effect of various levels of abomasal glucose, corn starch and corn dextrin infusion on small intestinal disappearance and net glucose absorption.

“…The fact that only a small amount of small intestinal starch disappearance can be accounted for as net portal glucose flux also was observed in steers fed 90% concentrate diets containing either wheat or sorghum (Gross et al, 1988). Expected small intestinal starch disappearance was 215 vs 1,147 g/d for steers consuming wheat and sorghum diets, respectively (Axe et al, 1987). Net portal glucose absorption in steers fed sorghum was only 3.78 g/h greater than that in steers fed wheat.…”