title: Abomasal infusion of soybean meal necessary to provide nitrogen retention equivalent to steer fed soybean meal.
abstract: Eight growing Angus steer calves averaging 213 kg were fitted with abomasal infusion cannulae to compare feeding 455 g of soybean meal (SBM) daily with infusing 120 g SBM abomasally (26% of intake) on nitrogen (N) retention and plasma urea and amino acid levels. A reversal design was used in which each steer received a SBM-supplemented diet plus water abomasally and an unsupplemented diet (basal) plus 120 g of SBM infused abomasally. Feeding a normal intake of SBM or infusing 26% of SBM intake post-ruminally (abomasally) resulted in similar daily N retention (18.4 g N for fed steers and 18.8 g N for infused steers). Total urinary output (liter/day), as well as urinary N losses (g/day), was 6.8 vs. 5.2 and 44.1 vs. 24.0 for the fed and infused groups of steers, respectively (P less than .05). Nitrogen retained expressed as a percent of N intake was 7.2% higher for SBM infusion. Daily fecal dry matter excretion was .25 kg greater for steers infused with SBM. Plasma urea levels were higher (P less than .05) for SBM-fed steers at each 2-hr sampling interval for 8 hr after feeding. Plasma free amino acid levels were similar for both groups of steers.
mesh_terms: D000018:Abomasum; D000284:Administration, Oral; D000596:Amino Acids / Q000097:blood; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D001806:Blood Urea Nitrogen; D002417:Cattle; D008297:Male; D009584:Nitrogen / Q000378:metabolism*; D013025:Glycine max
chemical_list: D000596:Amino Acids; D009584:Nitrogen