To study the effects of adding quinoa seed (raw grain) to the diet of the Luhua chicken on the cecal microorganism abundance and fatty acid composition of muscle, 120 49-day-old healthy female dewormed Luhua chickens (body weight 1476.21 ± 101.39 g) were randomly divided into 4 groups, with 3 replicates in each group and 10 chickens in each repetition. The control group (CK group) was fed a basal diet and the experimental groups were fed with 4% (Q4), 8% (Q8), and 12% (Q12) quinoa seed (raw grain) added to the basal diet for 75 days. After 121 days of age, the animals were slaughtered and the 16S rRNA characteristics of cecal flora, as well as composition and content of fatty acids in muscle, were determined and analyzed. The content of unsaturated fatty acids (UFAs), docosahexaenoic acid (C22:6n3; DHA) and n-3 polyunsaturated fatty acids (n-3 PUFAs) in the breast and leg muscles significantly increased in the experimental groups supplemented with quinoa seeds (p < 0.05). However, the content of saturated fatty acids (SAFs) and ratio of n-6/n-3 in breast muscle and leg muscle significantly decreased (p < 0.05). In addition, adding a certain percentage of quinoa seeds in the diet can also affect the community composition and content of microorganisms in the ceca of Luhua chickens. At the phylum level, the Proteobacteria, Actinobacteria, Synergistetes and Melainabacteria in experimental groups (Q4, Q8 and Q12) were significantly lower than those in the CK group (p < 0.05). At the genus level, Desulfovibrio, Synergistes, Olsenella, Parabacteroides, Mailhella, Sutterella and Ruminiclostridiu in group Q4 were significantly lower than those in group CK (p < 0.05) while Faecalibacterium in Q8 group, and Lawsonia and Faecalibacterium in Q12 group were significantly higher than those in the CK group (p < 0.05). Enrichment analysis of the microbial function showed that compared with the CK group, Metabolism and Enzyme Families were significantly enriched in the Q4 group (p < 0.05). Cellular Processes and Signaling were significantly enriched in the Q8 group (p < 0.05). The association analysis of fatty acids with microorganisms showed that the abundance of Faecalibacterium, Lawsonia and Meagmonas was significantly correlated with partial SFAs and UFAs (p < 0.05). In conclusion, adding quinoa seeds to diets significantly increased the content of muscle DHA, UFAs and n-3 PUFAs. The content of SAFs and the n-6/n-3 ratio were significantly reduced. Taken together, quinoa can effectively improve the cecal microbiota structure, inhibit the number of harmful bacteria and increase the number of beneficial bacteria, regulating the intestinal environment and promoting the body health of female Luhua chickens.
Keywords: 16S rRNA; Chenopodium quinoa; Luhua chickens; fatty acid; microorganisms.