Origin of starch and its effect on fermentation in the rumen and amino acids passage to the intestinum of cows

Abstract

Two origin of starch – maize and wheat were tested by using four non lactating cows with rumen and duodenal T- cannules in the experiment. Cr2 O3 was used as a marker of nutrient flow to the duodenum. Cows were fed diets consisting of, %: forage 70, maize and/or wheat meal 27 and/or 29, soyabeanmeal 2 and Vitamix S 1, on dry matter basis. Starch origin did not affect ruminal fermentation significantly. Concentration of all VFA was higher with wheat than with maize meal. The mean of acetate:propionate ratio was significantly higher (P<0.05) when wheat was fed. Maize in the diet significantly increased the flow of starch to the duodenum (21.4 % vs. 10.2 % from the daily intake). With both diets higher amounts of crude protein and amino acids passed to the duodenum than were ingested (101.8 % with wheat and 130.4 % with maize). In comparison with intake, flow of essential lysine (176.6% and 140.8 %) and nonessential glycin (289.7 % and 186.4 %) were the highest. It means that availability of energy and nitrogen by microbes in the rumen are more effective from maize than wheat as the starch origin.