Identification of Gut Microbiota Affecting Fiber Digestibility in Pigs.

Dietary fiber plays an important role in porcine gut health and welfare. Fiber is degraded by microbial fermentation in the intestine, and most gut microbiota related to fiber digestibility in pigs are worth pursuing. The aim of this study was to identify gut microbiota associated with the apparent total tract digestibility (ATTD) of neutral detergent fiber (NDF) and of acid detergent fiber (ADF) in pigs. Large phenotypic variations in the ATTD of NDF and of ADF were separately found among 274 Suhuai pigs. Microbial community structures were significantly different between high and low fiber digestibility groups. Fourteen genera separately dominated the communities found in the high ATTD (H-AD) of NDF and ADF samples and were in very low abundance in the low ATTD (L-AD) of NDF and ADF samples. In conclusion, norank_f__Bacteroidales_S24-7_group (p < 0.05), Ruminococcaceae_UCG-005 (p < 0.05), unclassified_f__Lachnospiraceae (p < 0.05), Treponema_2 (p < 0.01), and Ruminococcaceae_NK4A214_group (p < 0.01) were the main genera of gut microbiota affecting the ATTD of NDF in pigs. Christensenellaceae_R-7_group (p < 0.01), Treponema_2 (p < 0.05), Ruminococcaceae_NK4A214_group (p < 0.05), Ruminococcaceae_UCG-002 (p < 0.05), and [Eubacterium]_coprostanoligenes_group (p < 0.05) were the main genera of gut microbiota affecting the ATTD of ADF in pigs. The most important functions of the above different potential biomarkers were: carbohydrate transport and metabolism, general function prediction only, amino acid transport and metabolism, cell wall/membrane/envelope biogenesis, translation, transcription, replication, energy production and conversion, signal transduction mechanisms, and inorganic ion transport and metabolism. The most important metabolic pathways of the above different potential biomarkers were: membrane transport, carbohydrate metabolism, amino acid metabolism, replication and repair, translation, cell motility, energy metabolism, poorly characterized, nucleotide metabolism, metabolism of cofactors and vitamins, and cellular processes and signaling.

Polymorphism of VRTN Gene g.20311_20312ins291 Was Associated with the Number of Ribs, Carcass Diagonal Length and Cannon Bone Circumference in Suhuai Pigs.

The vertnin (VRTN) gene g.20311_20312ins291 was reported as an important variant related to the number of ribs (RIB), and the ins/ins genotype was advantageous for improving RIB of Western pigs. The purpose of this study was to determine whether the VRTN gene g.20311_20312ins291 influences RIB, carcass traits, and body size traits, including cannon bone circumference (CBC) in Chinese Suhuai pigs. We found that the VRTN gene g.20311_20312ins291 was polymorphic in Suhuai fattening pigs and gilts. The polymorphism of g.20311_20312ins291 was significantly associated with RIB and CDL in Suhuai fattening pigs (p < 0.01), whereas this variant had no influence on carcass weight (CWT). There was a tendency of association between this variant and carcass straight length (CSL) in Suhuai fattening pigs (p = 0.06). The polymorphism of g.20311_20312ins291 was also significantly associated with CBC in Suhuai gilts (p = 0.04). Furthermore, CBC was positively genetically correlated with body length (0.22, p < 0.01) and body weight (0.15, p < 0.01). Our results indicated that the VRTN gene g.20311_20312ins291 could be used as a potential marker for improving RIB, CDL, and CBC in Suhuai pigs.