Abstract
This study aimed to evaluate how the feeding strategy of rabbit kits at the onset of solid feed intake could affect ecological diversity and co-occurrence patterns of the cecal bacterial community. From birth to 18 days of age kits were exclusively milk-fed, and between 18 and 35 days the young rabbits also had access to solid feed. After weaning at (35 days), young rabbits were exclusively fed solid feed. Three experimental feeds were used: a high concentrate diet [H: 10.16 MJ digestible energy (DE)/kg and 15.3% crude protein (CP)], a low concentrate diet (L: 9.33 MJ DE/kg and 14.7% CP) and a reproductive female diet (R: 10.57 MJ DE/kg and 17.3% CP). The rabbit kits (n = 357) were divided into three groups, differing by the diet received during two periods: from 18 to 28 and from 28 to 49 days of age. In the groups LL and HH, rabbit kits were fed L or H diets, respectively, during both periods. Kits in the group RL received feeds R and L from 18 to 28 and 28 to 49 days of age, respectively. Cecal bacterial communities of 10 rabbits per group were carried out at 18, 28, 35, 43 and 49 days of age by MiSeq Illumina sequencing 16S rRNA encoding genes. Between 18 and 28 days of age, solid feed intake was higher in the group RL compared to the other two groups (+24%; P < 0.01). Overall, 13.4% of the OTUs detected were present in the cecal ecosystem from 18 to 49 days old, whereas 17.4% were acquired with the onset of solid feeding and kept from 28 days on. Exclusive milk consumption constrains the bacterial community toward a similar structure but high phylogenetic beta-diversity. Introduction of solid feed induced a sharp change of microbial community structure and decreased phylogenetic diversity. A strong relationship in bacterial community network occurred only from 43 days on. Our feeding strategy at the onset of solid feed ingestion exhibited only a moderate effect on the microbial community structure (P = 0.072), although the LL group seemed to reach faster maturity compared to the two other groups.
Highlights
The intestinal tracts of mammals are almost sterile at birth, where the installation and maturation of the bacterial communities are influenced by many factors, such as mode of delivery, milk source, the type of feeding and antibiotic therapy (Penders et al, 2006; Palmer et al, 2007; Koenig et al, 2011)
The digestive ecosystem plays an important role in the development and stimulation of intestinal immune system (GALT) (Thaiss et al, 2016), in rabbits where both the GALT and humoral immunity development is dependent on specific intestinal microbiota stimulation (Rhee et al, 2004; Mage et al, 2006)
Our results showed that the bacterial communities evolve with age, showing a gradual increase in alpha-diversity and in bacterial relationship network complexity over time, the change from a strictly milk based diet to solid feed had the most marked effect
Summary
The intestinal tracts of mammals are almost sterile at birth, where the installation and maturation of the bacterial communities are influenced by many factors, such as mode of delivery, milk source, the type of feeding and antibiotic therapy (Penders et al, 2006; Palmer et al, 2007; Koenig et al, 2011). Rabbit kits change from a milk rich in protein and fat (12.3 and 12.9 g/100 g, respectively, Maertens et al, 2006) to a feed that is rich in starch and vegetal protein, and poor in fat (140, 125 and 30 g/kg, respectively, Gidenne and Fortun-Lamothe, 2002). This drastic nutritional change coincides with a high occurrence of digestive problems and mortality rate. The introduction of feed better adapted to physiological stage of animals could improve the health of rabbit kits
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
