Dietary L-homoserine spares threonine in chicks

• Published in: The Journal of nutrition Vol. 139; no. 7; p. 1298
• Main Authors: Bryant, Kasey I, Dilger, Ryan N, Parsons, Carl M, Baker, David H
• Format: Journal Article
• Language: English
• Published: United States 01-07-2009
• Subjects: Animal Feed; Animals; Arachis; Chickens - growth & development; Chickens - metabolism; Diet; Homoserine - metabolism; Homoserine - pharmacology; Threonine - deficiency; Threonine - metabolism; Weight Gain; Zea mays
• ISSN: 1541-6100
• DOI: 10.3945/jn.109.104372

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 alpha-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.