Effects of dietary starch sources on pellet-processing characteristics, growth performance and caecal microflora of...

This study evaluated the effects of starch sources on pellet-processing characteristics as well as the growth performance and caecal microflora of rabbits. Ninety-six 35-day-old rabbits were randomly allocated to four groups with 24 rabbits per group and were fed diets with different starch sources (corn, wheat, potato or pea starch). The trial lasted for 40 days. The greatest hardness and lowest powder ratio of feed pellets was associated with the use of potato starch (p > 0.05). Pellet bulk density was the highest with corn starch, and the density was greater than that of pea starch by 5.91% (p < 0.05). The pulverisation ratio of corn starch pellets was the lowest, 43.67% lower than that of the pea starch pellets (p < 0.05). The average daily gain of rabbits in the corn starch group was higher than in the potato and pea starch groups, by 7.89% and 10.81%, respectively (p < 0.05). Rabbits in the corn starch group had the best feed conversion ratio (p > 0.05). The feed intake of rabbits in the potato starch group was higher than in the wheat and pea starch groups, by 4.30% and 5.16% respectively (p < 0.05). The dominant caecal bacteria phyla were Firmicutes, Bacteroidetes, Verrucomicrobia and Proteobacteria. There were 12 bacterial genera with proportions greater than 0.1%. The caecal proportion of Clostridium in the pea starch group was 1.8%, which was higher than those of the other groups (p = 0.057). There was no significant difference in caecal microbial diversity among groups (p > 0.05). The highest microbial clustering effect was found in the corn starch treatment. In conclusion, the best pellet quality was found using potato starch; for rabbit growth, the optimal source was corn starch.