Dehydrated Alfalfa and Fresh Grass Supply in Young Rabbits: Effect on Performance and Caecal Microbiota Biodiversity

Abstract

The improvement of rabbit gut microbiota by modifying nutritional components of the feed or favoring its early intake of feed has been previously investigated. The early administration of dehydrated alfalfa (A) or fresh grass (G) for rabbits, during the peri-weaning period (30 and 45 days of age), and their effect on performance and caecal microbiota compared to a standard diet (C) were evaluated. Until 15 days of age, nine litters/group were housed in the maternal cage and milked once per day. From 15 to 30 days, the young rabbits could consume both milk and solid feed (pelleted for C or supplemental feed for A and G). At 30 days of age, the rabbits were weaned and, until 45 days, were kept in single cages following the same dietary protocol. No significant changes were found in the milk intake or the individual weight of young rabbits at 30 and 45 days. The caecal Firmicutes/Bacteroidetes (bacterial phyla ratio) increased with age (from 2.43 to 6.05 on average, at 30 and 45 days). The Ruminococcaceae/Lachinospiraceae (bacterial family ratio) was highest in the A group at both ages, followed by G then C. The early administration of dehydrated alfalfa is a promising solution to improve health status by favoring an appropriate digestive microbiota.

Keywords: caecal microbiota; dehydrated alfalfa; fresh grass; peri-weaning feeding; rabbit.

Figure A1

Effect of dietary supplementation with dehydrated alfalfa or fresh grass in peri-weaning period on alpha-diversity rabbit caecal microbiota: (left) observed means species richness; (right) Shannon diversity. C = rabbit fed pelleted feed only; A = rabbit fed pelleted feed + dehydrated alfalfa; G = rabbit fed pelleted feed + fresh grass. ^a,b Values within a row with different superscript letters differ significantly at p < 0.05.

Figure A2

MDS plots of the rarefy weighted UniFrac distances (a) and Bray–Curtis distances (b) of caecal microbiota of rabbit fed a dietary supplementation of dehydrated alfalfa or fresh grass in peri-weaning period (those at 30 and 45 days of age were analyzed). Principal component (PC)1 and PC2 values for each sample are plotted; the percentage variation explained by each PC is shown in brackets. C = rabbit fed pelleted feed only; A = rabbit fed pelleted feed + dehydrated alfalfa; G = rabbit fed pelleted feed + fresh grass.

Figure 1

Feeding plan of experimental groups. The dotted bar represents the milking period; the full gray bar represents the pelleted feed administration; the small square bar represents the dehydrated alfalfa period of administration; the big square bar represents the fresh grass period administration. C = rabbit fed pelleted feed only; A = rabbit fed pelleted feed + dehydrated alfalfa; G = rabbit fed pelleted feed + fresh grass.

Figure 2

Total feed intake on a dry matter (DM) basis (A) and acid detergent fiber (ADF) intake (B) of young rabbits from 15 to 30 days of age. The dotted line represents rabbit fed pelleted feed + fresh grass (G group); the dashed line represents rabbit fed pelleted feed + dehydrated alfalfa (A group); the solid line represents rabbit fed pelleted feed (C group).

Figure 3

Effect of dietary supplementation with dehydrated alfalfa or fresh grass on peri-weaning period of rabbit caecal microbiota beta diversity. First axis of multidimensional scaling (MDS) ordination based on the Bray–Curtis distance matrix plotted against days of treatment. C = rabbit fed pelleted feed only; A = rabbit fed pelleted feed + dehydrated alfalfa; G = rabbit fed pelleted feed + fresh grass.

Figure 4

Effect of dietary supplementation with dehydrated alfalfa or fresh grass on peri-weaning period on relative abundances (%) of the different phyla of rabbit caecal microbiota at 30 and 45 days of age. C = rabbit fed pelleted feed only; A = rabbit fed pelleted feed + dehydrated alfalfa; G = rabbit fed pelleted feed + fresh grass.

Figure 5

Effect of dietary supplementation with dehydrated alfalfa or fresh grass on peri-weaning period on relative abundances (%) of the different families of rabbit caecal microbiota at 30 and 45 days of age. C = rabbit fed pelleted feed only; A = rabbit fed pelleted feed + dehydrated alfalfa; G = rabbit fed pelleted feed + fresh grass.