Table 3.
Selected feed additives targeting intestinal health of newly weaned pigs with additional references.
| Feed additive | Initial body weight or age | Feeding duration (day) | Observations | References |
|---|---|---|---|---|
| Fermented soybean meal | 5.5 ± 0.2 kg | 28 | Improved growth efficiency and reduced diarrhea | (83) |
| 35 day | 30 | Increased nutrient digestibility, and positively affected fecal microflora by increasing lactic acid bacteria and decreasing Escherichia coli count | (84) | |
| 35 day | 35 | Increased ADG and final body weight, and reduced serum urea nitrogen, increased serum immunoglobulin (Ig) G, IgM and IgA, and increased villus height of duodenum, jejunum, and ileum | (85) | |
| 5.97 ± 0.14 kg | 15 | Modulated the expression of genes related to inflammatory response and anti-oxidant activity leading to a reduction on serum cortisol after lipopolysaccharide challenge | (86) | |
| Fermented soybean protein | 5.8 ± 0.9 kg | 28 | Improved ADG, ADFI, FCR, and increased digestibility of dry matter, gross energy, crude protein, fat, Ca, P, and increased villus height of duodenum, jejunum, and ileum | (87) |
| Emulsifiers | 6.0 ± 0.2 kg | 14 | Positively affected fat digestibility | (88) |
| 7.9 ± 1.0 kg | 35 | Increased ADG, digestibility of dry matter, gross energy, and crude fat, and decreased serum triglyceride concentration | (89) | |
| 7.2 ± 0.1 kg | 19 | Increased villus height of duodenum and jejunum, enhanced barrier function and positively affected fat digestibility | (90) | |
| Probiotics | 7.7 ± 1.1 kg | 21 | Increased feed intake, ADG, and increased digestibility of nitrogen and phosphorus | (91) |
| 7.6 ± 0.6 kg | 42 | Improved ADG and FCR during 14-day post-weaning, increased protein digestibility, increased villus height of jejunum and ileum, and increased expression of tight junction proteins when added into a low crude protein diet. | (92) | |
| 21 day | 16 | Modulated intestinal microbiota by increasing Firmicutes phylum in the ileum and increased Actinobacteria phylum which includes Bifidobacteria in the colon | (93) | |
| 8.4 ± 0.2 kg | 28 | Microbial shifts in the porcine gut in response to diets containing E. faecalis were similar to the response to which containing antibiotics | (67) | |
| Prebiotics | 6.3 ± 0.3 kg | 28 | Increased growth efficiency, increased digestibility of dry matter and affected Bifidobacteria concentrations | (94) |
| 6.13 ± 0.13 kg | 14 | Selectively stimulated the number of Lactobacilli whereas suppressed E. coli and Sreptococcus. suis and improved intestinal barrier function | (95) | |
| 5.65 ± 0.27 kg | 21 | Upregulated the expression of TLR4 and calprotectin protein alleviating inflammation in the intestine and decreased diarrhea incidence challenged with enterotoxigenic E. coli | (96) | |
| 4.72 ± 0.23 kg | 21 | Increased apparent digestibility of crude protein, calcium, and phosphorus, and decreased the incidence of diarrhea, increased the fecal shedding of Lactobacillus reduced E. coli, and improved small intestinal morphology and enhanced the growth performance | (97) | |
| 4.9 ± 0.3 kg | 14 | Reduced incidence of diarrhea when challenged with E. coli. K88 | (98) | |
| Synbiotics | 4.8 ± 0.6 kg | 24 | Reduced diarrhea, and increased intestinal microbial diversity when challenged with E. coli K88 | (99) |
| 7.19 ± 0.45 kg | 28 | Improved ADG and FCR, increased digestibility of dry matter and crude protein, and increased the fecal abundance of Lactobacillus spp. and reduced Enterobacteriaceae counts | (100) | |
| 8.09 ± 0.25 kg | 28 | Modulated the microbiota by increasing Ruminococcaceae and Lachnospiraceae and decreasing Erysipelotrichaceae and Prevotellaceae. Enhanced intestinal fermentation by increasing the concentration of acetate in feces | (101) | |
| Xylanase | 10.7 ± 1.2 kg | 21 | Increased ADG, and digestibility of dry matter and gross energy, and reduced digesta viscosity, and reduced inflammatory response | (102) |
| 7.2 ± 0.4 kg | 24 | Enhanced growth performance and gut morphology, reduced digesta viscosity, reduced intestinal oxidative stress and the enterocyte proliferation | (103) | |
| 7.5 ± 0.1 kg | 19 | Increased digestibility of gross energy and total non-starch polysaccharide by increasing the digestibility of arabinoxylan. Reduced pro-inflammatory digesta viscosity, and improved intestinal barrier function | (104) | |
| Phytase | 28 day | 42 | Increased ADG, ADFI, and growth efficiency, and increased digestibility of minerals | (105) |
| 6.27 ± 0.01 kg | 35 | Enhanced growth performance and feed energy efficiency | (106) | |
| Protease | 6.3 ± 0.5 kg | 14 | Improved ADG, ADFI, FCR, reduced diarrhea, increased digestibility of crude protein, enhanced intestinal morphology, and increased nutrient transport efficiency | (107) |
| 8.3 ± 0.63 kg | 21 | Improved growth performance and reduced fecal score. Improved digestibility of dry matter, gross energy, crude protein, and phosphorus. Reduced ammonia nitrogen in cecum and colon and total volatile fatty acid in ileum and colon. Reduced the E. coli and increased Lactobacillus count in the colon | (108) | |
| 6.42 ± 0.12 kg | 42 | Enhanced growth performance and digestibility of dry matter, and nitrogen. Reduced blood creatinine and fecal NH3 | (109) | |
| Nucleotides | 4.8 ± 0.4 kg | 21 | Improved ADFI, positively affected ADG, and positively enhanced villus structure | (110) |
| 7.3 ± 0.1 kg | 28 | Improved ADG and ADFI | (111) | |
| 7.3 ± 0.3 kg | 42 | Increased final body weight, ADG, and growth efficiency, and increased digestibility of dry mater and energy | (112) | |
| Organic acids | 7.2 ± 0.2 kg | 42 | Improved ADG and FCR, increased villus height, increased acetic and propionic acid concentrations, and altered microbial community structure | (113) |
| 6.3 ± 0.6 kg | 14 | Reduced inflammatory cytokines and altered microbial community composition | (114) | |
| 8.63 ± 1.56 kg | 28 | Improved ADG and FCR. Reduced diarrhea score by reducing E. coli count in feces. Improved digestibility of dry matter, ether extract, total carbohydrates, fiber, and phosphorus and improved intestinal morphology | (115) | |
| Phytogenic feed additives | 21 day | 11 | Reduced diarrhea and inflammation when challenged with E. coli | (116) |
| 7.4 ± 1.3 kg | 35 | Increased post-weaning feed intake | (117) | |
| 8.4 ± 1.6 kg | 35 | Increased weight gain, improved fecal consistency, and increased digestibility of dry matter and crude protein | (118) | |
| 8.2 ± 2.3 kg | 22 | Decreased pro-inflammatory cytokines | (119) | |
| 25 day | 42 | Increased growth efficiency and increased nutrient digestibility | (120) | |
| Blood plasma | 5.5 ± 0.1 kg | 14 | Reduced diarrhea and decreased pro-inflammatory cytokines | (121) |
| 6.0 ± 0.1 kg | 14 | Increased growth efficiency and reduced activation of the immune system | (122) | |
| 6.8 ± 0.1 kg | 12 | Improved ADG, ADFI, and growth efficiency | (10) | |
| Mycotoxin deactivators | 8.2 ± 0.1 kg | 34 | Reduced oxidative stress and immune activation | (123) |
| 9.9 kg | 27 | Improved body weight, ADFI, and FCR | (124) | |
| 6.0 ± 0.3 kg | 35 | Improved body weight, ADG, and ADFI | (125) | |
| 9.1 ± 0.1 kg | 42 | Improved body weight, and ADG. Reduced TNFα, and 8-OHdG | (126) |