Dietary Supplementation with Lysine and Threonine Modulates the Performance and Plasma Metabolites of Broiler Chicken

Abstract

Here, we investigated whether the optimal threonine (Thr) to lysine (Lys) ratio in high Lys diet improves the growth performance of modern broiler chickens at finisher period and determined the possible mechanism underlying improvement in the growth performance of chickens fed with high Lys or Lys + Thr diet using metabolome analyses. Eighteen 21-day-old chickens housed in individual cages were randomly divided into three groups of six chickens fed with different diets as follows: control diet, high Lys diet (150% Lys content of National Research Council requirement), and high Lys + Thr diet (0.68 of Thr/Lys in high Lys diet). Body weight gain (BWG) increased in chickens receiving high Lys diet as compared with those fed with the control diet (P＜0.05); no significant difference was observed in BWG of chickens from high Lys + Thr and high Lys groups. Feed conversion ratio (FCR) was lower in chickens fed with high Lys or high Lys + Thr diet than in those on the control diet. Serotonin concentration increased in the plasma of chickens fed with high Lys diet as compared to those fed with other diets. A negative correlation was observed between plasma serotonin concentration and FCR. These results provide the first evidence on the use of high Lys in broiler diets to reduce FCR during finisher period, which may be associated with change in plasma serotonin concentration. These findings suggest that high Lys content in finisher diet, but not high Thr + Lys diet, may affect the peripheral serotonergic metabolism and improve FCR. Thus, plasma serotonin may serve as a biomarker of FCR in broilers.

The effect of the application of diets with varied proportions of arginine and lysine on biochemical and antioxidant status in Turkeys

“…The present study indicates that increasing the Lys level in the diet resulted in a decrease in the UREA level in the plasma of young turkeys. Similar results were obtained by Ishii et al (2019) in a study on broiler chickens receiving a diet containing 50% more Lys than recommended by the NRC (1994). In birds, as uricotelic organisms, the main product of the metabolism of nitrogen compounds (proteins, amino acids and purines) is UA, not urea UREA (Rezende et al, 2017).…”

Effects of Selenium Supplementation on Rumen Microbiota, Rumen Fermentation, and Apparent Nutrient Digestibility of Ruminant Animals: A Review

“…The net absorption of organic Se and its transport to the tissues in an intact form is greater than inorganic Se. Se-bound amino acids act as analogs of amino acids for non-specific protein synthesis, which promotes the incorporation of organic Se into nonfunctional structural proteins (e.g., in skeletal muscle) as a direct Met replacement [63,149]. In this respect, bacterial Se is reported to considerably increase intestinal villus height, which is associated with increased Se retention more than sodium selenite [148].…”

L-Leucine <i>In Ovo</i> Administration Causes Growth Retardation and Modifies Specific Amino Acid Metabolism in Broiler Embryos

“…Lys is an essential amino acid and the second limiting amino acid in broiler chicken diets based on corn and soybean. Dietary supplementation of Lys reduced the feed conversion ratio by increasing the plasma serotonin level in broiler chickens ( Ishii et al , 2019 ). Both Leu and Lys are exclusively ketogenic amino acids, and their carbon skeletons can be broken down into acetyl-CoA and acetoacetate, a ketone body ( Voet and Voet, 1995 ).…”