Impact of feed restriction on cecum microbiota and differential metabolites in serum of laying hens

Abstract

Caloric restriction with its beneficial effects has been studied in various species. In poultry, it has also been mentioned that feed restriction can affect various physiological states or have a protective effect on diseases. However, there are limited studies of feed restriction on elucidating the intestinal microbiota and metabolome profiles in chickens. This study aims to investigate distinct cecum microbiota and metabolite profiles in serum on chickens under different feed restriction status. Thirty Longman laying hens were divided into three groups, there are CR0 (caloric restriction) as a control, 20% caloric restriction of feed (CR20) and 40% caloric restriction of feed (CR40) for six weeks. The results showed that the average body weight was decreased from 1.79 kg to 1.55 kg and 1.37 in CR20 and CR40, respectively. The egg production rate also decreased by feed restricted treatment, and the most serve restriction reduced the egg production rate to less than 60%. For the cecum microbiota analysis, there was no difference in the diversity indices at CR20 or CR40 compared with CR0. The results show that Firmicutes, Bacteroidetes and Proteobacteria are the most common phyla in chicken ceca, and Cyanobacteria, Kiritimatiellaeota, Epsilonbacteraeota, Verrucomicrobia, Spirochaetes, Synergistetes and Deferribacteres account for the remainder. The feed restriction treatments increase Cyanobacteria and Synergistetes population, whereas decrease the relative abundance of Epsilonbacteraeota. At the genus levels, the majority were Bacteroides, Rikenellaceae_RC9. Interestingly, Helicobacter was decrease, whereas Synergistetes and Mucispirillum were increase by 40% feed restriction. The non-targeted LC-QTOFMS results showed that stearidonic acid, 13-L-hydroperoxylinoleic acid, pyrrolidonecarboxylic acid, L-glutamine, L-tryptophan, LysoPC (15:0) and LysoPC (18:3) were increased by 20% feed restriction compared with control group. And some critical nutrients have been influenced by the restriction treatments, such as stearidonic acid, arginine, tryptophan, glutamine, histidine and serine were increased by 40% feed restriction. Interestingly, phenylalanine, choline, acetylserotonin, biotin, riboflavin, LysoPC (16:1) and (20:4) were decreased in CR40. In present study, we found for the first time that severe feed restrictions cause nutritional deficiencies, and the first limited nutrients are riboflavin, biotin, pantothenic acid, L-phenylalanine, choline, acrylic acid, glycolic acid. The above metabolites are rare discuss on restricted status in chickens. However, these finding can provide new insights for future investigation in poultry nutritional research.