title: The interactive effects of glycine, total sulfur amino acids, and lysine supplementation to corn-soybean meal diets on growth performance and serum uric acid and urea concentrations in broilers.
abstract: Four experiments were conducted to determine the interactive effects of Gly, TSAA, and Lys in corn-soybean meal diets on growth performance of broilers. All experiments were conducted with female Ross x Ross 308 or 708 broilers in brooder batteries from 0 to 18 d posthatching. Treatments had 5 to 8 replications with 5 or 6 broilers per replicate pen. Diets in all experiments were fed without or with Gly (2.32% total Gly + Ser). All diets contained 0.25% l-Lys.HCl except in experiment 1, where no crystalline Lys was added. In experiment 1, the total dietary Lys level was 1.26% with TSAA:Lys of 0.72 and 0.76. Increasing TSAA:Lys increased (P < 0.07) G:F. The main effect of Gly was not significant for ADG, ADFI, or G:F; however, G:F was increased by Gly in broilers fed 0.72 but not in those fed 0.76 TSAA:Lys (Gly x TSAA:Lys, P < 0.03). In experiment 2, the total dietary Lys level was 1.26% with TSAA:Lys of 0.51, 0.68, 0.72, and 0.76. Glycine addition did not affect ADG, ADFI, or G:F; however, increasing TSAA:Lys linearly increased (P < 0.01) ADG, ADFI, and G:F and the response was quadratic for ADG and G:F. Experiment 3 was similar to experiment 2 except the total dietary Lys level was 1.35%. Glycine addition increased (P < 0.03) G:F and decreased (P < 0.04) serum uric acid (SUA) and serum urea N concentrations. Also, increasing TSAA:Lys linearly and quadratically (P < 0.02) increased ADG, ADFI, and G:F. In experiment 4, broilers were fed 2 levels of total dietary Lys (1.26 and 1.35%), 3 levels of TSAA:Lys (0.72, 0.76, and 0.80), and without or with Gly supplementation up to a total of 2.32% Gly + Ser. Glycine addition increased ADG (P < 0.02) and G:F (P < 0.01). The increase in G:F with Gly was not the same for all TSAA:Lys (Gly x TSAA:Lys, P < 0.07). Increasing Lys increased (P < 0.01 to 0.10) ADG, ADFI, and G:F. Glycine addition increased ADG and ADFI more in broilers fed 1.35% Lys than in those fed 1.26% Lys (Lys x Gly, P < 0.09). Glycine addition increased SUA in broilers fed 1.26% Lys but decreased SUA in broilers fed 1.35% Lys (P < 0.01). Glycine addition decreased SUA in broilers fed the TSAA:Lys of 0.80 but not at the other TSAA:Lys (P < 0.08). These data indicate that Gly increased G:F and decreased SUA in diets with 1.35% Lys and excess TSAA.
authors.affiliation: School of Animal Sciences, Louisiana State University Agricultural Center, Baton Rouge 70803, USA.
authors.forename: S
authors.initials: S
authors.lastname: Powell
authors.forename: T D
authors.initials: TD
authors.lastname: Bidner
authors.forename: L L
authors.initials: LL
authors.lastname: Southern
mesh_terms: D000603:Amino Acids, Sulfur / Q000494:pharmacology; D000821:Animal Feed; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D002645:Chickens / Q000254:growth & development* / Q000378:metabolism; D004032:Diet / Q000662:veterinary*; D019587:Dietary Supplements; D005260:Female; D005998:Glycine / Q000494:pharmacology; D008239:Lysine / Q000494:pharmacology; D013025:Glycine max; D014508:Urea / Q000097:blood*; D014527:Uric Acid / Q000097:blood*; D003313:Zea mays
chemical_list: D000603:Amino Acids, Sulfur; D014527:Uric Acid; D014508:Urea; D008239:Lysine; D005998:Glycine