Effects of Dietary Protein Levels on Bamei Pig Intestinal Colony
Compositional Traits
Abstract
Diets containing different crude protein levels (16%, 14%, and 12%)
were created to feed Bamei pigs in order to study the effect of these
compositions on intestinal colonies. Therefore, 27 healthy Bamei pigs of
similar weight (20.99 kg±0.16 kg) were selected and randomly divided
into three groups for microbial diversity analysis. The results of this
study show that microbial diversities and abundances in Bamei pig
jejunum and caecum samples after feeding with different dietary protein
levels were significantly different. Dietary crude protein level exerted
no significant effect on the Shannon index for cecum microbes in these
pigs, while Simpson, ACE, and Chao1 indices for group I were all
significantly higher than those of either the control group or group II
(P < 0.05). Indeed, data show that microbial diversities and
abundances in the 14% protein level group were higher than those in
either the 16% or 12% groups. Dominant bacteria present in jejunum and
cecum samples given low-protein diets were members of the phyla
Firmicutes and Bacteroidetes. Data show that as dietary crude protein
level decreases, representatives of the microbial flora genus
Lactobacillus in jejunum and cecum samples gradually increases. Values
for the KEGG functional prediction of microbial flora at different
dietary protein levels also shows that genes of jejunum and cecum
microorganisms were mainly enriched in the ‘metabolism’ pathway, and
indicate that low protein diets increase intestinal metabolic activity.
Therefore, we recommend that Bamei pig dietary protein levels are
reduced 2% from their existing level of 16% crude protein. We also
suggest that essential synthetic amino acids (AA) are added to optimize
this ideal protein model as this will increase intestinal flora
diversity in these pigs and enhance health. These changes will have a
positive effect in promoting the healthy growth of Bamei pigs.