Effects of dietary protein restriction followed by realimentation on growth performance and liver transcriptome alterations of lamb

K Cui,B Wang,T Ma,Q Y Diao,B W Si,N F Zhang,Y Tu

doi:10.1038/s41598-018-33407-w

Abstract

The present study aimed to investigate the compensatory effect of early protein restriction followed by a realimentation on growth performance of lamb and to explore the transcriptomic changes in liver. Thirty-two lambs with an initial birth weight of 2.3 ± 0.20 kg that were weaned on day 15 were randomly divided into two groups. The lambs were fed a basal diet with normal protein level (NPL, protein level in the milk replacer and starter, 25 and 21%, respectively) or low protein level (LPL, protein level in the milk replacer and starter, 19 and 15%, respectively) from 15 to 60 d, after which all lambs consumed the same diet with a normal protein level from 61 to 90 d. Protein restriction led to a significant decrease in average daily gain (ADG), body weight and liver weight (P < 0.05). Transcriptome analysis showed that 302 or 12 differentially expressed genes (DEGs) were identified during the restriction or recovery periods, respectively (P < 0.05). The Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis indicated that DEGs enriched in nutrient metabolism and antioxidant capacity were down-regulated, while vessel development and immunity response-related genes up-regulated. The genes involved in metabolism of tyrosine were still down-regulated in the realimentation phase. Studies in this area indicated the accelerated growth effect of early protein restriction followed by a realimentation on growth performance of lambs and explored the transcriptomics change of liver which can help to develop feeding strategies to optimize the use of feedstuffs and in providing a new perspective for the study of early nutrition and epigenetics in later life.

Highlights

The strategies to reduce the cost of lamb production in China include the imposition of feed restrictions when cultivated forages are scarce or expensive or feed supplements are not economical viable
Compensatory growth is manifested in the ability of animals previously restricted in feed intake to outgain their better counterparts when given free access to good quality feed
Compared to the normal protein level (NPL) group, the average daily gain (ADG) of lambs in the low protein level (LPL) group exhibited an accelerate effect after realimentation for 30 days, but there is no statistical differences between treatments

Summary

Introduction

The strategies to reduce the cost of lamb production in China include the imposition of feed restrictions when cultivated forages are scarce or expensive or feed supplements are not economical viable. Compensatory (catch-up) growth was defined as a physiological process in which the organism accelerates its growth after a period of restricted development usually because of the restriction of feed intake[2] This phenomenon is known to occur in many species of abalone[3], shrimp[4], fish[5], pigs[6], goats[7] and lambs[8]. Knowledge of the mechanism of protein restriction and realimentation on growth performance and gene expression alterations can help in developing feeding strategies to optimize the use of feedstuffs, it could offer a new perspective for the study of early dietary factors and nutritional epidemiology in later life

Methods

Results

Conclusion