Abomasal infusion of soybean meal necessary to provide nitrogen retention equivalent to steer fed soybean meal.
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.
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
D000596:Amino Acids; D009584:Nitrogen