Incorporation of unfermented or fermented de-oiled rice bran meal into a rabbit’s diet impacts growth performance, nutrient digestibility, cecal microbiota composition, and intestinal barrier function

TL;DR

This study shows that adding fermented or unfermented rice bran meal to rabbit diets improves digestion and intestinal health, with fermented rice bran being more beneficial.

Contribution

The study introduces the use of fermented rice bran meal as a corn and soybean meal alternative in rabbit diets, showing improved intestinal and digestive benefits.

Findings

Fermented rice bran meal (FRBM) improved nutrient digestibility and intestinal morphology compared to control and unfermented rice bran meal (UFRBM).

FRBM increased short-chain fatty acids like acetate and butyrate in rabbit ceca, promoting gut health.

FRBM enhanced solute carrier family 15 and 5 levels, indicating better nutrient transport in the intestines.

Abstract

This study assessed the effects of incorporating unfermented or fermented rice bran meal (RBM) into a rabbit’s diet on their growth performance, cecal microbiota, and intestinal health.

Twenty-one male weaned New Zealand White rabbits aged 6 weeks were randomly allocated into 3 groups (n = 7). Rabbits consumed the basal diet in the control (CON) group and the basal diet with a 20% substitution of either unfermented RBM (UFRBM) or fermented RBM (FRBM) for 8 weeks. A combination of Lactobacillus johnsonii L63 with hydrolytic enzymes ([cellulase (100 U/g], phytase [1.25 U/g], and papain [300 U/g]) was used to FRBM for 60 h at 37°C and a pH value of 4.8.

Our results demonstrated that the rabbits’ growth performance, serum biochemical variables, and cecal microbiota for α and β diversities at the phylum level didn’t differ among the treatments. The nutrient digestibility, cecal and jejunal morphology, or α-amylase and trypsin activities increased in the FRBM group than the CON and UFRBM groups, while the catalase and malondialdehyde activities decreased in the UFRBM group (p<0.05). The solute carrier families 15 and 5 levels were higher in the FRBM group than the UFRBM and CON groups, while the UFRBM group improved the levels of the solute carrier family 1, occludin, and V9D2013 group at the genus level than the FRBM and CON groups (p<0.05). The abundance of glycolysis-to-gluconeogenesis was increased in the FRBM and UFRBM groups compared to the CON group (p<0.05). The total short-chain fatty acid, acetate, and butyrate concentrations were, respectively, improved in the FRBM group than the CON and UFRBM groups (p<0.05).

The two formulas incorporating 20% of UFRBM or FRBM in rabbit diet should be recommended to farmers, particularly the FRBM, to decrease the reliance on corn and soybean meal for rabbit production.

Figures