Guanidinoacetic acid supplementation on growth performance and molecular mechanisms of lean mass gain in nursery pigs

ABSTRACT: The objective with the present study was to evaluate the effect of guanidinoacetic acid (GAA) on the growth performance of nursery piglets as well as a possible molecular mechanism of action on lean mass gain. Seventy-two pigs, weaned at 21 d, weighing 6.80 ± 1.2 kg were distributed in a completely randomized design into one of three dietary treatments (control, control + 1.2 g/kg GAA or control + 2.4 g/kg GAA) and 8 replicates per treatment. The control diet was an animal protein-free diet based on corn and soybean meal. Body weight, average daily weight gain, average daily feed intake and feed efficiency were evaluated at 35, 49, and 56 days. At the end of the experiment, one animal per pen was slaughtered and samples of the vastus lateralis muscle were collected for RT-qPCR and protein abundance analysis. Overall (from 21 to 56 d), GAA supplementation improved feed efficiency (P摘要：本试验旨在评估胍乙酸（guanidinoacetic acid, GAA）对保育仔猪生长性能的影响及其调控瘦肉增重的潜在分子机制。选取72头21日龄断奶、初始体重为6.80±1.2 kg的仔猪，采用完全随机试验设计分为3组日粮处理组（对照组、基础日粮添加1.2 g/kg GAA组、基础日粮添加2.4 g/kg GAA组），每组设置8个重复。对照组日粮为以玉米与豆粕为基础的无动物蛋白日粮。分别于试验第35、49、56天测定仔猪体重、平均日增重、平均日采食量及饲料效率。试验结束时，每栏选取1头仔猪屠宰，采集股外侧肌样本用于实时定量逆转录PCR（RT-qPCR）与蛋白丰度分析。整体试验周期（21至56日龄）内，添加GAA可改善饲料效率（P