253 - The Effect of Increasing Standardized Ileal Digestible Methionine Intake on Whole-body Nitrogen Retention of Gilts During Late Gestation

Tuesday, June 28, 2022

5:00 PM – 5:15 PM CT

Location: Oklahoma City Convention Center, Ballroom A

Presenting Author(s)

CM

Cristhiam J. Munoz Alfonso, n/a

Ph.D. Student
University of Guelph
Guelph, ON

Author(s)

John K. Htoo, n/a

Director Technical Support Swine
Evonik Operations GmbH
Hanau-Wolfang, Hessen
Lee-Anne Huber, n/a

Assistant Professor
University of Guelph
Guelph, ON

Abstract: A total of 70 gestating gilts (166±13 kg BW) were used to determine whole-body N retention when standardized ileal digestible (SID) methionine (Met) was fed at one of seven levels (n=10), ranging between 50 and 150% of estimated requirements during late gestation. The experimental diets provided excess Cys and 2.61, 3.39, 4.44, 5.22, 6.00, 7.05, and 7.83 g SID Met/d, respectively, with a feed allowance of 2.61 kg/d. Diets were fed to individual gilts for a 7-d adaptation period followed by a N balance period between gestation days 109 and 112. Contrast statements were used to determine linear and quadratic effects of the dietary inclusion level of Met. The average N intake was 70.8 g/d among treatments. Urinary N excretion decreased with increasing SID Met content, with no further change after 3.39 g/d SID Met (quadratic; P < 0.0001). Fecal N excretion decreased with increasing SID Met content, with no further change after 5.22 g/d SID Met (linear and quadratic; P < 0.0001 and P < 0.05, respectively). Whole-body N retention increased as SID Met content increased between 2.61 and 4.44 g/d SID Met, no differences were observed between 4.44 and 7.05 g/d SID Met, with intermediate N retention for gilts fed 7.83 g/d SID Met (linear and quadratic; P < 0.01 and P < 0.0001). Whole-body N retention efficiency (% of intake) was greatest (60.74%) at 7.05 g/d SID Met.Whole-body N retention (g/d) was optimized at 4.04 and 4.58 g/d SID Met based on linear and quadratic broken-line linear models, respectively, for gilts during late gestation. Therefore, for whole-body protein retention, the average SID Met requirements (4.31 g/d) appear to be less versus those recommended by the NRC in late gestation (5.22 g SID Met/day), which do not take into consideration the non-protein partitioning of dietary Met.