Effects of rearing system and narasin on growth performance, gastrointestinal development, and gut microbiota of broilers

Abstract

This study was conducted to evaluate the effects of 3 rearing systems ( FL : flooring litter rearing, MC : multilayer cage rearing, PN : plastic net rearing) with or without supplemental narasin on growth performance, gastrointestine development and health of broilers. A total of 2,400 one-day-old Ross 308 mixed-sex broilers (1:1 ratio of males and females) were used in a completely randomized design utilizing a 3 × 2 factorial arrangement of treatments, with 12 replicates per treatment. Each replicate for FL, MC, and PN consisted of 34 birds per floor pen, 30 birds per cage, and 36 birds per net pen, respectively, ensuring the same stocking density (12 birds/m 2 ) across the 3 systems. Results showed that lower ADG (average daily gain), ADFI (average daily feed intake), and FCR (feed conversation ratio) observed in the MC group than those of the other 2 systems from 1 to 36 d of age ( P < 0.05). Narasin inclusion in the diets decreased ADFI and FCR significantly ( P < 0.05). Multilayer cage and PN rearing systems reduced the relative weight of the gizzard significantly ( P < 0.05). Compared with FL, MC reduced the relative weight of the duodenum, jejunum, and ileum ( P < 0.05). The mRNA expression levels of the ileal IL-1β and IFN-γ in FL were higher than those in PN and MC ( P < 0.05). Narasin decreased the ileal mRNA expression of TNF-α ( P < 0.05). Different rearing systems changed the ileal microflora structure of broilers. The FL system increased the ileal microbial diversity of broilers and the relative abundance of Actinobacteria . Narasin combined with MC increased the relative abundance of Proteobacteria . In conclusion, birds reared in PN had a higher body weight. The MC birds had poorer intestinal development and health condition, higher abundance of Proteobacteria , but better FCR. The FL rearing appeared to be propitious for gastrointestinal development and health. Narasin inclusion in the diets improved FCR and changed the relative abundance Proteobacteria of broilers.

Comparative study on the hygienic, production and economic indices of Japanese quails reared on floor and cage systems.

“…1). These results agreed with (Yan et al, 2020) who said that that floor rearing usually leads to a richer gut microbiota than other systems. The environmental conditions could alter the gut microbiota, as the FS usually leads to a richer, and more diverse gut microbiota than other systems (Cui et al, 2017).While our results disagreed with (Li et al, 2017).…”

Effects of cage versus floor rearing system on goose intestinal histomorphology and cecal microbial composition

“…The differences may be caused by the change in feed intake of geese. Some studies have found that the changes in the rearing systems will affect the feed intake of poultry ( Starčević et al, 2021 ; Yan et al, 2021 ).…”

Centennial Review: Factors affecting the chicken gastrointestinal microbial composition and their association with gut health and productive performance

“…Therefore the majority of colonization of the chick gut with bacteria begins right after hatching via contact with environmental sources at the hatchery, mainly people handling the eggs, transportation boxes, and any feed and water or bedding material available ( Kizerwetter-Świda and Binek, 2008 ; Stanley et al, 2014 ). Young chickens at 1 and 2 d of age are delivered to commercial farms where they are usually placed in bedding material, although rearing of chicks in plastic nets is also practiced in some countries such as China ( Chen et al, 2020 ; Yan et al, 2021 ). Several microbiota taxa from new or reused bedding material and other environmental sources such as feed continue the initial colonization of the gut ( Wang et al, 2016 ).…”