Effects of low-protein diets supplemented with lysine on growth performance and serum indexes of piglets
DING Xiao
ZHAO Xiaogang
GUO Jiyu
WAN Fachun
Abstract：The experiment aimed to investigate the effects of low-protein diets supplemented with lysine on the growth performance,serum biochemical indicators,antioxidant capacity,and amino acid content of piglets.A total of 150'Duroc × Landrace × Yorkshire' piglets with a weight of(19.40±0.54)kg were selected and randomly divided into six groups,with five replicates per group and five piglets per replicate.A 3 × 2 factorial experimental design was adopted to feed diets with different crude protein levels(16.50％,17.50％and 18.50％)and lysine levels(1.32％and 1.25％).By adjusting the addition amount of restrictive amino acids,the ratio of methionine+cysteine,threonine,tryptophan and valine to lysine in the diet was fixed at 0.56,0.68,0.16 and 0.63,respectively.The pre-test period was three days and the formal test period was 25 days.The results showed that compared with the crude protein 17.50％group,total protein,globulin and urea nitrogen concentrations in serum of crude protein 16.50％group were significantly decreased(P＜0.05),while the total protein content of crude protein 18.50％group was significantly reduced(P＜0.05),and the serum urea nitrogen content was significantly increased(P＜0.05).Compared with the crude protein 17.50％group,the serum total superoxide dismutase and glutathione peroxidase activities in crude protein 16.50％and 18.50％groups were significantly reduced(P＜0.05).Compared with the protein 17.50％group,the arginine,leucine,phenylalanine,aspartic acid and alanine concentrations in the crude protein 16.50％and 18.50％groups were significantly reduced(P＜0.05).The study indicates that supplementation with lysine can achieve the same growth performance in piglets with crude protein 17.50％group as in those with crude protein 18.50％group,while having little effect on the growth performance of piglets with protein 16.50％group.
Keywords：pigletsproteinlysinegrowth performanceserum indexes
Publication Date：2025-08-16
Online Publishing Date：2025-10-14(First online date of this platform, not the publication date of the document)
Pages：6( 25-30 )