Two metabolism trials were conducted with yearling steers fed mature native forage to measure the effect of supplemental protein degradability on selected metabolic variables. Supplements contained 40% crude protein equivalence. In Trial 1, four abomasal-cannulated steers weighing 290 to 379 kg were fed supplements containing the following N sources: (1) 15% @entity4336 , 85% @entity1133 (U); (2) 100% @entity1460 meal (SBM); (3) 10% @entity4336 , 40% @entity1460 meal, 50% @entity1133 (SBM-U) and (4) 14% @entity4336 , 36% blood meal, 50% @entity1133 (BM-U). Equal portions of the daily diet (2.2% of body weight) were fed every 2 h. Treatment differences were not significant for organic matter digestibility, abomasal organic matter flow, nonammonia N flow, feed N flow, bacterial N flow and efficiency of microbial protein synthesis. There was a positive (P less than .05) relationship between quantity of slowly degraded protein fed and nonammonia N flow (r = .97) or feed N flow (r = .98). Escape N was determined to be 21.5, 16.5 and 54.2% in SBM, SBM-U and BM-U supplements, respectively. In the second trial, no supplement, SBM, SBM-U and BM-U were fed in a N balance trial. Dry matter, crude protein and neutral detergent fiber digestibilities were higher (P less than .05) for steers fed supplemented diets. Acid detergent fiber digestibility was higher (P less than .05) for steers supplemented with SBM than steers fed the unsupplemented diets. @entity1568 retention was greater (P less than .05) for @entity291 fed SBM and BM-U than for @entity291 fed SBM-U or no supplement.(ABSTRACT TRUNCATED AT 250 WORDS)

Influence of protein degradability in range supplements on abomasal @entity1568 flow, XXXX balance and nutrient digestibility.

@entity1568 :: ('MESH:D009584', 'Chemical') :: ['Nitrogen'] @entity1133 :: ('MESH:D014508', 'Chemical') :: ['urea'] @entity4336 :: ('381124', 'Species') :: ['corn'] @entity1460 :: ('3847', 'Species') :: ['soybean'] @entity291 :: ('9913', 'Species') :: ['cattle']
@entity1568 :: (MESH:D009584,Chemical) :: ['nitrogen']
