This study aimed to investigate the effects of chronic exposure to low levels of dietary aflatoxin B₁ (AFB₁) on growth performance, apparent total tract digestibility and intestinal health in pigs. In a 102-day experiment, fourteen barrows (Duroc×Landrace×Yorkshire, initial BW = 38.21 ± 0.45 kg) were randomly divided into control (CON, basal diet) and AFB₁ groups (the basal diet supplemented with 280 μg/kg AFB₁). Results revealed that the AFB₁ exposure decreased the final BW, ADFI and ADG in pigs (p < 0.10). AFB₁ exposure also decreased the apparent total tract digestibility of dry mater and gross energy at 50 to 75 kg and 105 to 135 kg stages, and decreased the apparent total tract digestibility of ether extract at 75 to 105 kg stage (p < 0.05). Meanwhile, AFB₁ exposure increased serum diamine oxidase activity and reduced the mRNA abundance of sodium-glucose cotransporter 1, solute carrier family 7 member 1 and zonula occluden-1 in the jejunal mucosa (p < 0.05). Furthermore, AFB₁ exposure decreased superoxide dismutase activity (p < 0.05) and increased 8-hydroxy-2′-deoxyguanosine content (p < 0.10) in jejunal mucosa. AFB₁ exposure also increased tumor necrosis factor-α, interleukin-1β and transforming growth factor-β mRNA abundance in jejunal mucosa and upregulated Escherichia coli population in colon (p < 0.05). The data indicated that chronic exposure to low levels of dietary AFB₁ suppressed growth performance, reduced the apparent total tract digestibility and damaged intestinal barrier integrity in pigs, which could be associated with the decreased intestinal antioxidant capacity and the increased pro-inflammatory cytokine production.

Pea fiber (PF) is a potential fibrous supplement in swine production. The influence of dietary PF on microbial community in the colon of pigs remains largely unexplored. Methanogens in the hindgut of monogastric animals play important roles in degradation of dietary fibers and efficient removal of microbial metabolic end product H2. Understanding the impact of dietary PF on the structure of colonic methanogens may help understand the mechanisms of microbe-mediated physiological functions of PF. This study investigated the influence of PF on the diversity and quantity and/or activity of colonic methanongens of piglets and finishing pigs. Four archaeal 16S rRNA clone libraries were constructed for piglets and finishers fed with control (Piglet-C and Finisher-C) or PF diet (Piglet-P and Finisher-P). There were 195, 190, 194 and 196 clones obtained from the library Piglet-C, Piglet-P, Finisher-C and Finisher-P, respectively, with corresponding 12, 11, 11 and 16 OTUs (operational taxonomic units). Significant differences of Shannon Index among the four libraries were found (P < 0.05). Libshuff analysis showed that the archaeal community structure among the four libraries were significantly different (P < 0.0001). The predominant methanogens shifted from Methanobrevibacter to Methanobrevibacter and Methanomassiliicoccus-like genus as a result of dietary PF. Supplementation of PF significantly increased the copy numbers of mcrA and dsrA genes (P < 0.05). Alteration of methanogenic community structure may lead to functional transition from utilization of H2/CO2 to employment of both H2/CO2 and methanol/CO2. Quantification of three functional genes (mcrA, dsrA and fhs) of methanogens, sulfate-reducing bacteria (SRB) and acetogens revealed that dietary PF also increased the activity of methanogens and SRB,probably associated with increased proportion of Methanomassiliicoccus luminyensis-species. Further study is required to examine the interaction between specific methanogens and SRB during fermentation of dietary PF.

Tryptophan can alleviate stress and improve intestinal health, but the precise mechanism has not been fully elucidated. This study aimed to examine the effects of tryptophan supplementation on antioxidant status, inflammation, endoplasmic reticulum (ER) stress, apoptosis, and pyroptosis signaling pathway in the intestine of piglets after Escherichia coli lipopolysaccharide (LPS) challenge. Thirty-two weaning piglets were allotted to four treatments including: non-challenged control, LPS-challenged control, LPS + 0.2% tryptophan and LPS + 0.4% tryptophan. On day 35 of feeding, piglets were injected intraperitoneally with 100 μg/kg of body weight LPS or saline. Among the LPS-challenged pigs, tryptophan supplementation improved intestinal morphology as indicated by greater villus height, villus area and smaller crypt depth, and antioxidant status, and decreased the mRNA expression and concentration of proinflammatory cytokines. Moreover, tryptophan downregulated the expression of ER stress (ER oxidoreductase-1α, ER oxidoreductase-1β, glucose-regulated protein-78, activating transcription factor 6, C/EBP homologous protein), apoptosis (B-cell lymphoma-2, BCL2-associated X protein, caspase 3), and pyroptosis signaling pathway (nucleotide-binding oligomerization domain-like receptor protein 3, caspase 1, gasdermin-D, apoptosis-associated speck-like protein containing a CARD). Collectively, tryptophan supplementation can contribute to gut health by improving antioxidant status and alleviating inflammation, ER stress, apoptosis, and pyroptosis in the intestine of piglets after lipopolysaccharide challenge.

This study aimed to investigate the effects of active dry yeast (ADY) on growth performance, rumen microbial composition and carcass performance of beef cattle. Thirty-two finishing beef cattle (yak ♂ × cattle-yaks ♀), with an average body weight of 110 ± 12.85 kg, were randomly assigned to one of four treatments: the low plane of nutrition group (control), low plane of nutrition group + ADY 2 g/head daily (ADY2), low plane of nutrition group + ADY 4 g/head daily (ADY4) and the high plane of nutrition group (HPN). Supplementation of ADY increased average daily gain compared to the control group. The neutral detergent fiber and acid detergent fiber apparent digestibility in HPN group was greater than that in control group. The propionic acid concentration in the rumen in ADY2, ADY4, and HPN groups was greater than that in control group. The Simpson and Shannon indexes in control and HPN groups were higher than that in ADY4 group. At the phylum level, the relative abundance of Firmicutes in the HPN group was higher than that in ADY4 group. The relative abundance of Ruminococcaceae UCG-002 in ADY4 group was higher than that in control and HPN groups. In conclusion, supplementation ADY 4 g/head daily shift the rumen microbial composition of beef cattle fed low plane of nutrition to a more similar composition with cattle fed with HPN diet and produce the similar carcass weight with HPN diet.

We conducted this experiment to determine if feeding 25-hydroxyvitamin D₃ (25(OH)D₃) to weaned pigs would alleviate porcine epidemic diarrhea virus (PEDV) infection and immune response. Forty-two weaned pigs were allotted to 1 of 6 dietary 25(OH)D₃ treatments (5.5, 5.5, 43.0, 80.5, 118.0, 155.5 μg 25(OH)D₃/kg diet) for 26 days. On day 22 of the trial, all the treatments were orally administrated with PEDV except for one of the 5.5 μg 25(OH)D₃/kg treatments, which was challenged with the same volume of sterile saline and served as control. Another 5.5 μg 25(OH)D₃/kg group for PEDV challenge was named CON-PEDV. Average daily gain (p < 0.05) was reduced by PEDV infection. PEDV administration also induced severe diarrhea (p < 0.05), reduction of villous height and the ratio of villous height to crypt depth, and increase of crypt depth and serum diamine oxidase activity (p < 0.05). Serum IgM and complement component 4 levels were increased by PEDV challenge. However, 155.5 μg 25(OH)D₃/kg supplementation alleviated intestinal damage (p < 0.05) compared with CON-PEDV. Furthermore, 155.5 μg 25(OH)D₃/kg supplementation downregulated the mRNA abundance of inflammatory cytokines and interferon signal pathway-related genes (p < 0.05) compared with CON-PEDV. These results suggested that dietary supplementation of 155.5 μg 25(OH)D₃/kg could alleviate intestinal damage and protect against PEDV-induced inflammatory status.

To determine responses of neonatal intestine to maternal increased consumption of DL-methionine (DLM) or DL-2-hydroxy-4-methylthiobutanoic acid (HMTBA), eighteen primiparous sows (Landrace × Yorkshire) were allocated based on body weight and backfat thickness to the control, DLM and HMTBA groups (n = 6), with the nutritional treatments introduced from postpartum d0 to d14. The DLM-fed sows showed negative energy balance manifested by lost bodyweight, lower plasma glucose, subdued tricarboxylic acid cycle, and increased plasma lipid metabolites levels. Both villus height and ratio of villus height to crypt depth averaged across the small intestine of piglets were higher in the DLM and HMTBA groups than in the control group. Piglet jejunal oxidized glutathione concentration and ratio of oxidized to reduced glutathione were lower in the HMTBA group than in the DLM and control groups. However, piglet jejunal aminopeptidase A, carnitine transporter 2 and IGF-II precursor mRNA abundances were higher in the DLM group than in the HMTBA and control groups. Increasing maternal consumption of methionine as DLM and HMTBA promoted neonatal intestinal growth by increasing morphological development or up-regulating expression of genes responsible for nutrient metabolism. And increasing maternal consumption of HMTBA promoted neonatal intestinal antioxidant capacity without compromising maternal energy homeostasis during early lactation.