QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 139/7/1298    most recent jn.109.104372v1 Purchase Article View Shopping Cart Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Bryant, K. I. Articles by Baker, D. H. PubMed PubMed Citation Articles by Bryant, K. I. Articles by Baker, D. H.

---

Nutrient Physiology, Metabolism, and Nutrient-Nutrient Interactions

Dietary L-Homoserine Spares Threonine in Chicks^1,2

Department of Animal Sciences and Division of Nutritional Sciences, University of Illinois, Urbana, IL 61802

Four chick bioassays were conducted to evaluate the threonine (Thr) replacement value of L-homoserine (HS). Growth rate was increased (P < 0.05) by dietary addition of 800 mg L-HS/kg diet to a purified diet severely deficient in Thr or by the addition of 800 or 1000 mg of L-HS/kg diet to a corn-peanut meal diet distinctly deficient in Thr. The addition of an isomolar level of -ketobutyrate, a catabolic product of both Thr and HS, did not elicit a response. Standard-curve methodology predicted a Thr replacement value of 38 ± 9% for HS. Interactions (P < 0.01) were observed in assays 2 and 4 between dietary Thr adequacy and 800 or 1000 mg L-HS/kg supplementation. Thus, HS improved growth performance when added to a Thr-deficient diet (0.46 g Thr/100 g diet), but it decreased growth performance when added to the same diet containing surfeit Thr (0.80 g Thr/100 g diet). The results indicate that low levels of HS elicit a growth response in young chicks fed Thr-deficient diets.

^* To whom correspondence should be addressed. Email: dhbaker{at}illinois.edu.

Manuscript received 8 January 2009. Initial review completed 27 February 2009. Revision accepted 5 May 2009.

Published online 27 May 2009.