Intestinal starch disappearance increased in steers abomasally infused with starch and protein1,2

Abstract

Steers (379 +/- 10 kg) with ruminal, duodenal, and ileal cannulas were used in a 5 x 5 Latin square digestion trial to quantify and evaluate the relationship between intestinal protein supply and intestinal starch disappearance. Treatments were infusions of 0, 50, 100, 150, or 200 g/d of casein along with 1,042 g/d of raw cornstarch. Abomasal infusions were accomplished by passing tubing and a pliable retaining washer through the reticular-omasal orifice into the abomasum. Steers were fed a 93% corn silage, 7% supplement diet that contained 12% crude protein at 1.65% body weight in 12 equal portions/d. Periods lasted 17 d (12 d for adaptation, 2 d of collections, and 3 d of rest). The quantity and percentage of organic matter and protein disappearance from the small intestine increased linearly (P < 0.03) with infused casein. Greater quantities of starch disappeared with increased casein infusion (P < 0.01). The infusion of 200 g/d of casein increased small intestinal starch disappearance by 226 g/d over the control. Casein infusion did not affect the quantity or percent of organic matter, starch, or protein disappearance in the large intestine. Treatments did not change ruminal ammonia N, ruminal pH, or plasma glucose concentrations. Starch disappearance from the small intestine was increased with greater protein flow to the duodenum of steers.

Effects of Synchronization of Energy and Nitrogen Release in the Rumen on the Starch Disappearance in the Gastrointestinal Tract and Growth Performance of Hanwoo Steers

“…In the previous study (Kim et al, 2010), steers fed C-CGM showed higher percentage of starch apparently digested post-ruminally than B-SBM. It was explained by higher duodenal CP flow for steers fed C-CGM over B-SBM diet, which was supported by the results of Taniguchi et al (1993) and Richards et al (2002) who concluded that starch disappearance from the small intestine was increased with greater protein flow to the duodenum of steers. Taniguchi et al (1995) and Richards et al (2003) suggested increased pancreatic α-amylase secretion, in response to increased duodenal CP supply, is responsible for improvements in small intestinal starch disappearance.…”

“…Huntington (1997) emphasized in his review that production and outflow of microbial protein from the rumen is responsible for starch digestion in the small intestine. Works with sheep (Taniguchi et al, 1993) and steers (Richards et al, 2002) showed that starch disappearance from the small intestine was increased with greater protein infused into the duodenum.…”

Factors affecting intestinal starch digestion in ruminants: A review

“…This suggested that casein (or protein) may somehow improve intestinal starch disappearance. Richards et al (2002) measured intestinal disappearance of starch in steers abomasally infused with starch and casein and showed that starch disappearance was increased with casein infusion. Further research showed that pancreatic α-amylase secretion also increased when casein was infused abomasally (Richards et al 2003).…”

Feeding strategies for improving productivity of growing steers fed grass silage

“…Thus, this suggests a negative effect on ruminal starch degradability when removing ruminal N provided by the SS supplement, although the basal diet was providing substantial soluble N from silage. In contrast, higher total tract digestibility of total non-structural carbohydrate was observed when dietary undegradable CP was increased (Bruckental et al 2002) or following abomasal infusion of casein (Richards et al 2002). Apparent digestibility of NDF tended to be lower (P 00.07) and was numerically lower for ADF for GC than for CC supplemented diets (Table 4).…”