Twenty-four Quarter @entity1641 weanlings (120    10 d) were blocked by age into 4 groups (n=6) for a 56-d trial to evaluate the influence of dietary Met concentration on growth and N balance. Weanling @entity1641 were housed by block and individually fed concentrates twice daily at 1.75% BW (as-fed basis). Weanling @entity1641 were randomly assigned to 1 of 4 concentrate treatments: basal (0.20 Met), basal + 0.03% Met (0.23 Met), basal + 0.07% Met (0.27 Met), and basal + 0.11% Met (0.31 Met). Diets were formulated to be isonitrogenous and isocaloric and contained equal amounts of Lys and Thr. Coastal bermudagrass hay (Cynodon dactylon) was individually fed at 0.75% BW (as-fed basis). Growth measurements, BW, rump fat, and plasma were obtained every 7 d. The final 4 d consisted of total collection of urine and feces. Feed, fecal, and urine samples were analyzed for N content, and N balance was calculated. Urine was analyzed for @entity1133 and @entity3265 concentrations. Plasma was analyzed for @entity1133 concentration. Grain, hay, and fecal samples were analyzed for nutrient composition. Data were analyzed using the PROC MIXED procedure of SAS. Linear, quadratic, and cubic effects were tested in the form of contrasts. There was no influence (P>0.25) of treatment on growth measurements, N balance, or urinary @entity1133 or @entity3265 . Intake of Lys and Thr did not differ (P>0.08) among treatments. @entity1853 intake increased as expected with increasing Met inclusion in the diet (P<0.01). Plasma @entity1133 N responded quadratically (P=0.04) to treatment. An unexpected peak in PUN was observed with 0.27 Met. The results indicate future studies that can ensure Met as the only dietary variable are necessary to better explain the Met requirements of weanling @entity1641 .

Influence of dietary @entity1853 concentration on growth and nitrogen balance in weanling Quarter XXXX .

@entity1853 :: ('MESH:D008715', 'Chemical') :: ['Methionine'] @entity1641 :: ('9796', 'Species') :: ['Horse', 'horses'] @entity1133 :: ('MESH:D014508', 'Chemical') :: ['urea'] @entity3265 :: ('MESH:D000641', 'Chemical') :: ['ammonia']
@entity1641 :: (9796,Species) :: ['Horses']
