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ARS Home » Midwest Area » Ames, Iowa » National Animal Disease Center » Food Safety and Enteric Pathogens Research » Research » Publications at this Location » Publication #125475
Title: IDEAL DIETARY TRYPTOPHAN REGIMEN FOR PIGS AS INFLUENCED BY ANTIGEN EXPOSURE JT MEET AM DAIRY SCI ASSOC; AM MEAT SCI ASSOC; AM SOC ANIM SCI; POULTRY SCI

Author
item MACHADO, C - IOWA STATE UNIVERSITY
item STAHLY, T - IOWA STATE UNIVERSITY
item Stabel, Thomas

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 7/28/2001
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Pigs from a high lean strain were reared via a SEW procedure and self-fed a basal diet containing 100% of ideal ration (IR; NRC, 1998) of digestible tryptophan (Trp) to digestible lysine (Lys). At 30 d of age, pigs were allotted within litter to one of four dietary ratios of Trp:Lys: 50, 75, 100, or 125%. The basal diet consisted of a corn-SBM-gelatin mixture containing a growth limiting amount of digestible Lys (0.95%) and all other essential amino acids, except Trp, at ratios greater than 100% of IR. Tryptophan was added as L- Tryptophan at the expense of cornstarch. Half of the pigs were administered subcutaneously a non-replicating antigen, autoclaved BCG (13 x 10**6 CFU/mg), at a dose of 0.20 mg/kg BW on d 4, 8, and 12. BCG induces IFN-gamma synthesis and thus indoleamine 2-3 dioxygenase release, which degrades tryptophan in several body tissues. BW gain, gain:feed ratio (GF) and body nitrogen accretion (NA) were determined for three consecutive four-day periods (d 4-16). As dietary Trp:Lys ratios increased, daily BW gain (79, 280, 518, 528 g), GF (.26, .52, .71, .68) and daily N accretion (3.6, 8.7, 13.9, 14.3 g) increased quadratically (P < .01) independent of BCG and period. BCG depressed (P < .05) BW gain (316 vs. 386 g), GF (0.51 vs. 0.57), and NA (9.2 vs. 11.1 g) with the magnitude of the depression increasing from d 8 through 16. In conclusion, the IR of Trp:Lys (NRC, 1998) was not altered by exposure to autoclaved BCG, a nonreplicating antigen.