Effect of creep feeding pelleted starter diet, liquid milk replacer and a liquid mixture of starter diet and milk replacer to suckling pigs on their growth and medication usage.

The aim of this study was to assess the effect of creep-feeding solid starter diet, liquid milk replacer, and a liquid mixture of starter diet and milk replacer to suckling pigs on their growth and medication usage up to target slaughter weight (approximately 120 kg). Ninety-one sows and their litters were randomly assigned to one of four post-farrowing treatments at day 107 of gestation; (1) no creep feed provided to weaning at day 28 of age (CONTROL; n = 20), (2) dry pelleted starter diet provided as creep feed from day 10 of age to weaning (DPS; n = 25), (3) liquid milk replacer provided as creep feed from day 3 of age to weaning (LMR; n = 23), and (4) liquid milk replacer provided from days 3 to 6 of age followed by a mixture of liquid milk replacer with an increasing proportion of liquid starter diet to weaning provided as creep feed (LMR + S; n = 23). Pig weight and dry matter disappearance (DMd) were recorded during lactation and postweaning until pigs reached target slaughter weight (approximately 120 kg). At target slaughter weight, carcass weight and quality were recorded. Medication (antibiotic and anti-inflammatory) usage per pig on a litter basis, and number of injections and clinical cases of disease per litter were recorded from birth to slaughter. At day 5 postweaning, a subset of pigs (n = 40) were sacrificed and intestinal samples were collected for histological analysis. Piglets supplemented with DPS had higher DMd of creep feed than those supplemented with LMR or LMR + S (P < 0.001). Providing LMR + S to suckling piglets reduced the coefficient of variation (CV) for within-litter piglet weaning weight (P < 0.01) compared to DPS and LMR, but the CV of LMR + S was similar to that of CONTROL. Providing DPS or LMR to suckling piglets increased piglet weaning weight compared to CONTROL (P < 0.001) but pig weight was not significantly different from CONTROL at time points thereafter. Gain to feed ratio from weaning to day 6 postweaning was less for LMR pigs compared to all other treatments (P < 0.001). Providing DPS or LMR + S to suckling piglets tended to increase postweaning ileal villus height (P = 0.07). Diarrhea incidence, as well as the number of clinical cases of disease and injections per litter and volume of antibiotic and anti-inflammatory administered per pig pre- and postweaning, were not affected by treatment (P > 0.05). In conclusion, supplementing suckling pigs with liquid milk replacer or dry pelleted starter diet improved growth at weaning, but the benefit did not persist to slaughter.

Postpartum meloxicam administration to sows but not split-suckling increases piglet growth and reduces clinical incidence of disease in suckling piglets.

Each suckling pig should receive ≥200 g of colostrum within the first 24 h of life, but with increased litter size this is now difficult to achieve. The aim of this study was to assess the effect of split-suckling and postpartum meloxicam provision to sows as a means of ensuring adequate colostrum intake, on growth and health in pigs pre- and postweaning. One hundred and four sows (Large White × Landrace) and their litters, averaging 16.3 piglets born alive, were assigned to one of four treatments in a two-by-two factorial arrangement. Factors were provision of meloxicam (yes/no; Mel/N-Mel) and split-suckling (yes/no; Split/N-Split). Meloxicam was administered intramuscularly at 0.4 mg/kg body weight to sows on release of the placenta (~2 h postpartum). Split-suckling commenced 4 h after birth of the first piglet, with the six heaviest piglets removed from the sow for 1 h to allow the lightest piglets to suckle. This was repeated after 1.5 h. Pigs were weighed at birth and at days 1, 6, 14, and 27 after birth and at days 6, 14, 21, 28, 47, and 129 postweaning. Carcass data were collected at slaughter. Medication usage was recorded from birth to slaughter. There was a split-suckling by meloxicam interaction effect at days 1 to 6 (P < 0.001) and days 6 to 14 (P < 0.001) after birth. Meloxicam administration had no effect on average daily gain (ADG) when split-suckling was applied; however, when split-suckling was not applied, postpartum meloxicam administration increased ADG. There was a meloxicam × split-suckling interaction for ADG from weaning to day 6 postweaning (P = 0.03). Meloxicam increased ADG when split-suckling was applied but not in its absence. Carcass weight was increased by meloxicam (P = 0.01) but was not affected by split-suckling (P > 0.05). Meloxicam use in sows reduced the number of clinical cases of disease (P = 0.04) in suckling pigs which tended to reduce the volume of antibiotics (P = 0.08) and anti-inflammatories (P = 0.08) administered. Split-suckling had no effect on medication usage in sows and piglets during lactation but increased their use from weaning to slaughter. In conclusion, postpartum administration of meloxicam to sows is an easily implemented strategy. It reduced clinical cases of disease, increased ADG in pigs during the first two weeks of life and early postweaning and increased carcass weight at slaughter. However, no split-suckling benefit was observed.

Suckling pigs should receive ≥200 g of colostrum (the first secretion of the mammary gland after giving birth) within the first 24 h of life. This is challenging to achieve as the number of piglets born alive has increased over the last decade, but the sow's ability to produce colostrum has not increased. Split-suckling (removing advantaged pigs from the sow for a period of time to allow weaker littermates time to suckle without competition) and/or administering an anti-inflammatory pain-killer to sows after farrowing may help to ensure adequate colostrum intake, thereby ensuring optimal piglet growth and health. The objective of this study was to assess the effect of split-suckling and/or postpartum provision of meloxicam, a nonsteroidal anti-inflammatory, on growth and health in pigs. The provision of meloxicam to sows increased pig growth pre- and postweaning, and increased carcass weight at slaughter. Furthermore, meloxicam reduced disease and tended to reduce antibiotic and anti-inflammatory usage in pigs prior to weaning. Split-suckling reduced pig growth pre- and postweaning and did not impact carcass weight or medication usage prior to weaning. Providing meloxicam to sows postfarrowing is a simple effective strategy to increase pig growth and reduce the need for medication.

Maternal and/or post-weaning supplementation with Bacillus altitudinis spores modulates the microbial composition of colostrum, digesta and faeces in pigs.

This study examined the effects of maternal and/or post-weaning Bacillus altitudinis supplementation on the microbiota in sow colostrum and faeces, and offspring digesta and faeces. Sows (n = 12/group) were assigned to: (1) standard diet (CON), or (2) CON supplemented with probiotic B. altitudinis spores (PRO) from day (d)100 of gestation to weaning (d26 of lactation). At weaning, offspring were assigned to CON or PRO for 28d, resulting in: (1) CON/CON, (2) CON/PRO, (3) PRO/CON, and (4) PRO/PRO, after which all received CON. Samples were collected from sows and selected offspring (n = 10/group) for 16S rRNA gene sequencing. Rothia was more abundant in PRO sow colostrum. Sow faeces were not impacted but differences were identified in offspring faeces and digesta. Most were in the ileal digesta between PRO/CON and CON/CON on d8 post-weaning; i.e. Bacteroidota, Alloprevotella, Prevotella, Prevotellaceae, Turicibacter, Catenibacterium and Blautia were more abundant in PRO/CON, with Firmicutes and Blautia more abundant in PRO/PRO compared with CON/CON. Lactobacillus was more abundant in PRO/CON faeces on d118 post-weaning. This increased abundance of polysaccharide-fermenters (Prevotella, Alloprevotella, Prevotellaceae), butyrate-producers (Blautia) and Lactobacillus likely contributed to previously reported improvements in growth performance. Overall, maternal, rather than post-weaning, probiotic supplementation had the greatest impact on intestinal microbiota.

Selected Nutrition and Management Strategies in Suckling Pigs to Improve Post-Weaning Outcomes.

Weaning is a critical period in a pig's life. Piglets are confronted with abrupt changes to their physical and social environment, as well as management and nutritional changes. Weaning has always been associated with a growth check and is frequently accompanied by post-weaning diarrhoea in piglets. However, rapid increases in litter size in the last decade have increased within-litter piglet weight variation, with piglets now generally lighter at weaning, making the challenges associated with weaning even greater. Many interventions can be employed during the suckling period to ease the weaning transition for piglets. Pre-weaning strategies such as supervised farrowing (assistance with suckling and oxytocin provision), the provision of pain relief to sows around farrowing, split-suckling, early oral supplementation with glucose, bovine colostrum, faecal microbiota transplantation, feed additives and solid and liquid creep feeding (milk and liquid feed) have all been investigated. The objective of these strategies is to stimulate earlier maturation of the digestive tract, improve immunity, reduce latency to the first feed post-weaning and increase early post-weaning feed intake and growth. This review focuses in particular on: (1) pain relief provision to sows around farrowing, (2)split-suckling of piglets, (3) pre-weaning provision of supplementary milk and/or liquid feed, (4) other strategies to stimulate earlier enzyme production (e.g., enzyme supplementation), (5) other nutritional strategies to promote improved gut structure and function (e.g., L-glutamine supplementation), and (6) other strategies to modulate gut microbiota (e.g., probiotics and prebiotics). Correctly implementing these strategies can, not only increase post-weaning growth and reduce mortality, but also maximise lifetime growth in pigs.

Antibacterial plant combinations prevent postweaning diarrhea in organically raised piglets challenged with enterotoxigenic Escherichia coli F18.

Antibiotics and zinc oxide restrictions encourage the search for alternatives to combat intestinal pathogens, including enterotoxigenic Escherichia coli (ETEC), a major cause of postweaning diarrhea (PWD) in pigs. PWD causes important economic losses for conventional and organic farming. This study investigated the effect of dietary supplementation with garlic and apple pomace or blackcurrant on infection indicators and the fecal microbiota of organic-raised piglets challenged with ETEC-F18. For 21 days, 32 piglets (7-weeks-old) were randomly assigned to one of four groups: non-challenge (NC); ETEC-challenged (PC); ETEC-challenged receiving garlic and apple pomace (3 + 3%; GA); ETEC-challenged receiving garlic and blackcurrant (3 + 3%; GB). ETEC-F18 was administered (8 mL; 109 CFU/ml) on days 1 and 2 postweaning. The 1st week, PC had lower average daily gain than those in the NC, GA, and GB groups (P < 0.05). NC pigs showed neither ETEC-F18 shedding nor signs of diarrhea. The PC group had higher diarrhea incidence and lower fecal dry matter than NC (≈5-10 days; 95% sEBCI). The GA and GB groups showed reduced ETEC-F18 and fedA gene shedding, higher fecal dry matter, and lower diarrhea incidence than the PC (≈5-9 days; 95% sEBCI). The NC, GA, and GB had normal hematology values during most of the study, whereas the PC had increased (P < 0.05) red blood cells, hemoglobin, and hematocrit on day 7. Haptoglobin and pig-MAP increased in all groups, peaking on day 7, but PC showed the greatest increase (P < 0.05). The fecal microbiota of PC pigs had reduced α-diversity (day 7; P < 0.05) and higher volatility (days 3-14; P < 0.05). Escherichia, Campylobacter, and Erysipelothrix were more abundant in the PC than in the NC, GB, and GA groups (log2FC > 2; P < 0.05), whereas Catenibacterium, Dialister, and Mitsoukella were more abundant in the NC, GB, and GA than in the PC group (log2FC > 2; P < 0.05). Prevotella and Lactobacillus were more abundant in the GB group (log2FC > 2, P < 0.05). In conclusion, dietary supplementation of GA and GB limited ETEC proliferation, reduced PWD, and beneficially impacted the fecal microbiota's diversity, composition, and stability.

Maternal supplementation with Bacillus altitudinis spores improves porcine offspring growth performance and carcass weight.

The objective of this study was to evaluate the effect of feeding Bacillus altitudinis spores to sows and/or offspring on growth and health indicators. On day (D) 100 of gestation, twenty-four sows were selected and grouped as: control (CON), fed with a standard diet; and probiotic (PRO), fed the standard diet supplemented with B. altitudinis WIT588 spores from D100 of gestation until weaning. Offspring (n 144) from each of the two sow treatments were assigned to either a CON (no probiotic) or PRO (B. altitudinis-supplemented) treatment for 28 d post-weaning (pw), resulting in four treatment groups: (1) CON/CON, non-probiotic-supplemented sow/non-probiotic-supplemented piglet; (2) CON/PRO, non-probiotic-supplemented sow/probiotic-supplemented piglet; (3) PRO/CON, probiotic-supplemented sow/non-probiotic-supplemented piglet and (4) PRO/PRO, probiotic-supplemented sow/probiotic-supplemented piglet. B. altitudinis WIT588 was detected in the faeces of probiotic-supplemented sows and their piglets, and in the faeces and intestine of probiotic-supplemented piglets. Colostrum from PRO sows had higher total solids (P = 0·02), protein (P = 0·04) and true protein (P = 0·05), and lower lactose (P < 0·01) than colostrum from CON sows. Maternal treatment improved offspring feed conversion ratio at D0-14 pw (P < 0·001) and increased offspring body weight at D105 and D127 pw (P = 0·01), carcass weight (P = 0·05) and kill-out percentage (P < 0·01). It also increased small intestinal absorptive capacity and impacted the haematological profile of sows and progeny. There was little impact of pw treatment on any of the parameters measured. Overall, the lifetime growth benefits in the offspring of B. altitudinis-supplemented sows offer considerable economic advantages for pig producers in search of alternatives to in-feed antibiotics/zinc oxide.

Intestinal microbiota modulation and improved growth in pigs with post-weaning antibiotic and ZnO supplementation but only subtle microbiota effects with Bacillus altitudinis.

The objective was to evaluate the effect of dietary Bacillus altitudinis spore supplementation during day (D)0-28 post-weaning (PW) and/or D29-56 PW compared with antibiotic and zinc oxide (AB + ZnO) supplementation on pig growth and gut microbiota. Eighty piglets were selected at weaning and randomly assigned to one of five dietary treatments: (1) negative control (Con/Con); (2) probiotic spores from D29-56 PW (Con/Pro); (3) probiotic spores from D0-28 PW (Pro/Con); (4) probiotic spores from D0-56 PW (Pro/Pro) and (5) AB + ZnO from D0-28 PW. Overall, compared with the AB + ZnO group, the Pro/Con group had lower body weight, average daily gain and feed intake and the Pro/Pro group tended to have lower daily gain and feed intake. However, none of these parameters differed between any of the probiotic-treated groups and the Con/Con group. Overall, AB + ZnO-supplemented pigs had higher Bacteroidaceae and Prevotellaceae and lower Lactobacillaceae and Spirochaetaceae abundance compared to the Con/Con group, which may help to explain improvements in growth between D15-28 PW. The butyrate-producing genera Agathobacter, Faecalibacterium and Roseburia were more abundant in the Pro/Con group compared with the Con/Con group on D35 PW. Thus, whilst supplementation with B. altitudinis did not enhance pig growth performance, it did have a subtle, albeit potentially beneficial, impact on the intestinal microbiota.

Effect of Raw and Extruded Propionic Acid-Treated Field Beans on Energy and Crude Protein Digestibility (In-Vitro and In-Vivo), Growth and Carcass Quality in Grow-Finisher Pigs.

The in-vitro ileal digestibility of dry matter (DM), organic matter (OM), and crude protein (CP) of field beans treated with propionic acid (trFB) and extruded trFB (exFB) was determined in experiment 1. The DE and dCP values of trFB and exFB were determined using the difference method in experiment 2. The effect of replacing SBM with trFB and exFB in grow-finisher diets on growth, carcass quality, apparent ileal digestibility (AiD), and total tract digestibility (ATTD) of DM, OM, gross energy (GE), and CP were investigated in experiment 3. In exp. 1, in-vitro digestibility of exFB compared to trFB was unchanged for DM (p = 0.12), increased for OM (p < 0.05), and increased for CP (p < 0.05). In exp. 2, the DE value of trFB and exFB was 14.38 and 15.75 MJ/kg respectively; and the dCP value was 21.35% and 21.42% respectively (on DM basis). In exp. 3, ADFI was higher for pigs fed trFB and exFB compared to the control diet (CON; p < 0.05), while ADG, FCR and carcass quality parameters of pigs did not differ among treatments (p > 0.05).

Microbial Quality of Liquid Feed for Pigs and Its Impact on the Porcine Gut Microbiome.

There is evidence that spontaneous fermentation frequently occurs in liquid pig feed that is intended to be delivered as fresh liquid feed, often with a resultant deterioration in the microbial and nutritional quality of the feed, which can negatively affect pig health and growth. Strategies including controlled fermentation with microbial inoculants, pre-fermentation or soaking of the cereal fraction of the diet, enzyme supplementation and dietary acidification have been employed to inhibit pathogens and prevent deterioration of feed nutritional quality, with promising results obtained in many cases. This review evaluates the impact of these strategies on the microbial quality of liquid feed and discusses how they can be further improved. It also investigates if/how these strategies impact the pig gut microbiota and growth performance of liquid-fed pigs. Finally, we review liquid feed system sanitisation practices, which are highly variable from farm to farm and discuss the impact of these practices and whether they are beneficial or detrimental to liquid feed microbial quality. Overall, we provide a comprehensive review of the current state of knowledge on liquid feed for pigs, focusing on factors affecting microbial quality and strategies for its optimisation, as well as its impact on the pig gut microbiome.

Impact of Intestinal Microbiota on Growth and Feed Efficiency in Pigs: A Review.

This review summarises the evidence for a link between the porcine intestinal microbiota and growth and feed efficiency (FE), and suggests microbiota-targeted strategies to improve productivity. However, there are challenges in identifying reliable microbial predictors of host phenotype; environmental factors impact the microbe-host interplay, sequential differences along the intestine result in segment-specific FE- and growth-associated taxa/functionality, and it is often difficult to distinguish cause and effect. However, bacterial taxa involved in nutrient processing and energy harvest, and those with anti-inflammatory effects, are consistently linked with improved productivity. In particular, evidence is emerging for an association of Treponema and methanogens such as Methanobrevibacter in the small and large intestines and Lactobacillus in the large intestine with a leaner phenotype and/or improved FE. Bacterial carbohydrate and/or lipid metabolism pathways are also generally enriched in the large intestine of leaner pigs and/or those with better growth/FE. Possible microbial signalling routes linked to superior growth and FE include increased intestinal propionate production and reduced inflammatory response. In summary, the bacterial taxa and/or metabolic pathways identified here could be used as biomarkers for FE/growth in pigs, the taxa exploited as probiotics or the taxa/functionality manipulated via dietary/breeding strategies in order to improve productivity in pigs.

Effect of cereal fermentation and carbohydrase supplementation on growth, nutrient digestibility and intestinal microbiota in liquid-fed grow-finishing pigs.

This study aimed to determine the impact of fermenting the cereal fraction of the diet (Cferm) and enzyme supplementation (ENZ) on the bacterial composition of the feed, nutrient digestibility, pig growth, feed efficiency (FE), intestinal volatile fatty acid (VFA) concentrations and intestinal microbiota composition. A total of 252 grow-finisher pigs (~ 40.4 kg; 7 pigs/pen) were randomly allocated to 4 diets in a 2 × 2 factorial arrangement for 55d. The diets were: (1) fresh liquid feed (Fresh); (2) Cferm liquid feed (Ferm); (3) Fresh + ENZ and (4) Ferm + ENZ. Cferm increased total tract nutrient digestibility, reduced caecal butyrate and propionate concentrations, and increased average daily gain (ADG). ENZ increased ileal and total tract nutrient digestibility, reduced caecal isobutyrate and propionate concentrations, and improved FE. Bacterial taxa positively correlated with pig growth (Lactobacillus kisonensis in the ileum and Roseburia faecis in the caecum) were more abundant in pigs fed ENZ diets, whereas most of the ileal bacterial taxa negatively correlated with growth (Megasphaera, Bifidobacterium and Streptococcus) had lower abundance in pigs fed Cferm diets. In conclusion, Cferm increased ADG and ENZ improved FE, with these improvements possibly mediated by increased nutrient digestibility, and beneficial modulation of the intestinal microbiota.

Effect of water-to-feed ratio on feed disappearance, growth rate, feed efficiency, and carcass traits in growing-finishing pigs.

The optimum proportion of water for preparing liquid feed to maximize growth and optimize feed efficiency (FE) in growing-finishing pigs is not known. The aim of the current study was, using an automatic short-trough sensor liquid feeding system, to identify the water-to-feed ratio at which growth was maximized and feed was most efficiently converted to live-weight. Two experiments were conducted in which four commercially used water-to-feed ratios were fed: 2.4:1, 3.0:1, 3.5:1, and 4.1:1 on a dry matter (DM) basis (the equivalent of 2:1, 2.5:1, 3.0:1, and 3.5:1 on a fresh matter basis). Each experiment comprised 216 pigs, penned in groups of 6 same sex (entire male and female) pigs/pen with a total of 9 pen replicates per treatment. The first experiment lasted 62 days (from 40.6 to 102.2 kg at slaughter) and the second experiment was for 76 days (from 31.8 to 119.6 kg at slaughter). Overall, in Exp. 1, FE was 0.421, 0.420, 0.453, and 0.448 (s.e. 0.0081 g/g; P < 0.01) for pigs fed at 2.4:1, 3.0:1, 3.5:1, and 4.1:1, respectively. Overall, in Exp. 2, average daily gain was 1,233, 1,206, 1,211, and 1,177 (s.e. 12.7 g/day; P < 0.05) for pigs fed at 2.4:1, 3.0:1, 3.5:1, and 4.1:1, respectively. At slaughter, in Exp. 1, dressing percentage was 76.7, 76.6, 76.7, and 75.8 (s.e. 0.17%; P < 0.01) for 2.4:1, 3.0:1, 3.5:1, and 4.1:1, respectively. There were no differences between treatment groups for DM, organic matter, nitrogen, gross energy, or ash digestibilities. These findings indicate that liquid feeding a diet prepared at a water-to-feed ratio of 3.5:1 maximizes FE of growing-finishing pigs without negatively affecting dressing percentage. Therefore, preparing liquid feed for growing-finishing pigs at a water-to-feed ratio of 3.5:1 DM is our recommendation for a short-trough liquid feeding system.

Effect of wet/dry, fresh liquid, fermented whole diet liquid, and fermented cereal liquid feeding on feed microbial quality and growth in grow-finisher pigs.

Fermented liquid feeding has proved beneficial for weaner pigs; however, there is limited research on its effect on the growth and feed conversion efficiency (FCE) of grow-finisher pigs. Microbial decarboxylation of amino acids is associated with whole diet fermentation, while wet/dry and liquid feeding reportedly improve growth compared with dry feeding. The objective of this study was to determine the effect of wet/dry feeding and fresh, fermented whole diet, and fermented cereal liquid feeding on pig growth, feed efficiency, and carcass quality in grow-finisher pigs. Pigs were allocated to one of four dietary treatments in two experiments: 1) Single-space wet/dry feeders (WET/DRY), 2) Fresh liquid feeding (FRESH), 3) Fermented cereal liquid feeding where the cereal fraction (38% barley, 40% wheat) of the diet was fermented prior to feeding (FERM-CER), and 4) Fermented whole diet liquid feeding where the whole diet was fermented prior to feeding (FERM-WH). In exp. 1, pigs were fed the experimental diets for 68 d prior to slaughter (29.8 kg ± 0.92 SE to 102.3 kg ± 0.76 SE). Overall, average daily gain (ADG) was 1,094, 1,088, 1,110, and 955 g/d (SE = 13.0; P < 0.001) and FCE was 2.26, 2.37, 2.40, and 2.88 (SE = 0.031; P < 0.001) for treatments one through four, respectively. Pigs fed FERM-WH were lighter at slaughter than pigs fed the other three treatments (P < 0.001). In exp. 2, pigs were on treatment for 26 d prior to slaughter (85.3 kg ± 1.69 SE to 117.5 kg ± 0.72 SE). Overall, ADG in exp. 2 was 1,103, 1,217, 1,284, and 1,140 g/d (SE = 27.9; P < 0.01) and FCE was 2.78, 2.99, 2.95, and 3.09 g/g (SE = 0.071; P = 0.05), for treatments one through four, respectively. There were no significant differences observed between treatments for apparent total tract digestibility of dry matter, organic matter, nitrogen, gross energy, or ash. Higher lactic acid bacteria counts and lower Enterobacteriaceae counts and pH were observed in FERM-CER and FERM-WH compared with WET/DRY and FRESH. Ethanol concentrations were almost 4-fold higher in FERM-CER troughs than FRESH troughs and 5-fold higher in FERM-WH than FRESH troughs. To conclude, FERM-WH resulted in poorer growth and FCE compared with WET/DRY, FRESH, and FERM-CER, probably due to amino acid degradation and a loss in gross energy found in FERM-WH.

Host-Microbiota Interactions in Ileum and Caecum of Pigs Divergent in Feed Efficiency Contribute to Nutrient Utilization.

The composition of the intestinal microbiota plays an important role in the digestion and utilization of nutrients and for gut health. Low-fiber diets stimulate digestion and absorption processes, predominantly in the upper region of the gastrointestinal tract, thereby increasing the conversion of feed into body weight. As a consequence, the chemical composition of digesta after duodenal and jejunal absorption processes and passage has a limited complexity affecting colonization and molecular profiles of enterocytes in the hind gut. To decipher ileal and caecal microbial ecosystems and host transcriptional profiles that are beneficial for effective use of the remaining nutrients, pigs differing in feeding efficiency were studied. Biological functions that were consistently enriched at both the gene and microbiota levels comprise immunity-related processes, which ensure the integrity of the gastrointestinal tract. In addition, the differential abundance of certain genera, including Rothia, Subdoligranulu, Leeia and Cellulosilyticum, reflects the establishment of a microbial profile that supports the digestion of endogenously indigestible dietary components in highly feed-efficient pigs. Overall, the results indicate the potential to promote these beneficial functions and further improve feed efficiency through manipulation of dietary and probiotic strategies.

The effect of feed form and delivery method on feed microbiology and growth performance in grow-finisher pigs.

There is no generally accepted optimal feed form and delivery method for feeding finisher pigs. The objective of this study was to compare the effect of feed form (meal and pellet) and delivery method (liquid, dry, and wet/dry) on feed microbiology and growth, gain-to-feed ratio (G:F), and carcass quality of finisher pigs. Two batches of pigs were used, each with six pen replicates per treatment. In each batch 216 pigs (32.7 kg; ± 0.48 SE) housed in same-sex (entire male or female) pens of six pigs per pen were on treatment for ~62 d prior to slaughter. The experiment was a 2 × 3 factorial arrangement with two factors for diet form (meal and pellets) and three factors for feed delivery (dry, wet/dry, liquid). The treatments were 1) meal from dry feeder, 2) meal from wet/dry feeder, 3) meal from liquid system, 4) pellet from dry feeder, 5) pellet from wet/dry feeder, and 6) pellet from liquid system. Pig growth performance was determined, blood samples collected at slaughter for hematological analysis and microbiological and proximate analysis of feed performed. A significant feed form × delivery interaction was found for G:F. During the overall period G:F was 0.446, 0.433, 0.423, 0.474, 0.459, and 0.418 g/g (SE = 0.0080; P < 0.01) for treatments 1 through 6, respectively. When feed was pelleted, G:F was improved when feed delivery was dry or wet/dry compared to meal but when the delivery was liquid, pelleting did not affect G:F. There were no interactive effects for overall average daily gain (ADG). Overall ADG was 1,114 and 1,156 g/d (SE = 16.9; P < 0.01) for pigs fed diets in meal and pellet form, respectively and 1,080, 1,114, and 1,210 g/d (SE = 18.4; P < 0.001) for dry-, wet/dry-, and liquid-fed pigs, respectively. Carcass weight was 76.6 and 79.0 kg (SE = 0.55; P < 0.001) for pigs fed in meal and pellet form, respectively, while it was 74.7, 77.3, and 81.5 kg (SE = 0.60; P < 0.001) for pigs delivered dry, wet/dry, and liquid diets, respectively. Lactic acid bacteria (P < 0.05) and yeast (P < 0.01) counts in troughs were greater for the liquid than the dry diet in both meal and pelleted form. There was also evidence of lysine degradation in the liquid diet but this did not impact pig growth. Feeding the diet in pelleted vs. meal form led to lower hemoglobin and greater white blood cell and neutrophil counts (P < 0.05). To conclude, wet/dry feeding of a pelleted diet is recommended to maximize growth rate while optimizing G:F in grow-finisher pigs.

Effect of cereal soaking and carbohydrase supplementation on growth, nutrient digestibility and intestinal microbiota in liquid-fed grow-finishing pigs.

Soaking the cereal fraction of a liquid diet prior to feeding (Csoak), and/or carbohydrase enzyme supplementation (ENZ) are likely to modulate both feed and intestinal microbial populations and improve feed efficiency (FE) in pigs. To test this hypothesis, a total of 392 grow-finisher pigs (~33.4 kg, 7 pigs/pen) were randomly allocated to 4 treatments in a 2 × 2 factorial arrangement for 70 days as follows: (1) fresh liquid feed (Fresh); (2) Cereal soaked liquid feed (Soak); (3) Fresh + ENZ and (4) Soak + ENZ. An interaction between ENZ and Csoak was found for average daily gain (ADG) during the growing phase (day 0 to 21; P < 0.05) where pigs fed the Soak + ENZ diet had higher ADG than pigs fed the Fresh + ENZ diet. No treatment effect was found for ADG thereafter. Enzyme supplementation increased total tract nutrient digestibility (P < 0.05) and reduced caecal VFA concentrations (P < 0.05) but did not improve pig growth or FE. Both Csoak and ENZ modulated intestinal microbiota composition; increasing abundance of bacterial taxa that were negatively correlated with pig growth and reducing abundance of taxa positively correlated with pig growth and caecal butyrate concentration. In conclusion, both strategies (Csoak and ENZ) improved nutrient digestibility in pigs and modulated intestinal microbiota composition.

Improvement of Feed Efficiency in Pigs through Microbial Modulation via Fecal Microbiota Transplantation in Sows and Dietary Supplementation of Inulin in Offspring.

As previous studies have demonstrated a link between the porcine intestinal microbiome and feed efficiency (FE), microbiota manipulation may offer a means of improving FE in pigs. A fecal microbiota transplantation procedure (FMTp), using fecal extracts from highly feed-efficient pigs, was performed in pregnant sows (n = 11), with a control group (n = 11) receiving no FMTp. At weaning, offspring were allocated, within sow treatment, to (i) control (n = 67; no dietary supplement) or (ii) inulin (n = 65; 6-week dietary inulin supplementation) treatments. The sow FMTp, alone or in combination with inulin supplementation in offspring, reduced offspring body weight by 8.1 to 10.6 kg at ∼140 days of age, but there was no effect on feed intake. It resulted in better FE, greater bacterial diversity, and higher relative abundances of potentially beneficial bacterial taxa (Fibrobacter and Prevotella) in offspring. Due to the FMTp and/or inulin supplementation, relative abundances of potential pathogens (Chlamydia and Treponema) in the ileum and cecal concentrations of butyric acid were significantly lower. The maternal FMTp led to a greater number of jejunal goblet cells in offspring. Inulin supplementation alone did not affect growth or FE but upregulated duodenal genes linked to glucose and volatile fatty acid homeostasis and increased the mean platelet volume but reduced ileal propionic acid concentrations, granulocyte counts, and serum urea concentrations. Overall, the FMTp in pregnant sows, with or without dietary inulin supplementation in offspring, beneficially modulated offspring intestinal microbiota (albeit mostly low-relative-abundance taxa) and associated physiological parameters. Although FE was improved, the detrimental effect on growth limits the application of this FMTp-inulin strategy in commercial pig production.IMPORTANCE As previous research suggests a link between microbiota and FE, modulation of the intestinal microbiome may be effective in improving FE in pigs. The FMTp in gestating sows, alone or in combination with postweaning dietary inulin supplementation in offspring, achieved improvements in FE and resulted in a higher relative abundance of intestinal bacteria associated with fiber degradation and a lower relative abundance of potential pathogens. However, there was a detrimental effect on growth, although this may not be wholly attributable to microbiota transplantation, as antibiotic and other interventions were also part of the FMT regimen. Therefore, further work with additional control groups is needed to disentangle the effects of each component of the FMTp in order to develop a regimen with practical applications in pig production. Additional research based on findings from this study may also identify specific dietary supplements for the promotion/maintenance of the microbiota transferred via the maternal FMTp, thereby optimizing pig growth and FE.

Porcine Feed Efficiency-Associated Intestinal Microbiota and Physiological Traits: Finding Consistent Cross-Locational Biomarkers for Residual Feed Intake.

Optimal feed efficiency (FE) in pigs is important for economic and environmental reasons. Previous research identified FE-associated bacterial taxa within the intestinal microbiota of growing pigs. This study investigated whether FE-associated bacteria and selected FE-associated physiological traits were consistent across geographic locations (Republic of Ireland [ROI] [two batches of pigs, ROI1 and ROI2], Northern Ireland [NI], and Austria [AT]), where differences in genetic, dietary, and management factors were minimized. Pigs (n = 369) were ranked, within litter, on divergence in residual feed intake (RFI), and 100 extremes were selected (50 with high RFI and 50 with low RFI) across geographic locations for intestinal microbiota analysis using 16S rRNA amplicon sequencing and examination of FE-associated physiological parameters. Microbial diversity varied by geographic location and intestinal sampling site but not by RFI rank, except in ROI2, where more-feed-efficient pigs had greater ileal and cecal diversity. Although none of the 188 RFI-associated taxonomic differences found were common to all locations/batches, Lentisphaerae, Ruminococcaceae, RF16, Mucispirillum, Methanobrevibacter, and two uncultured genera were more abundant within the fecal or cecal microbiota of low-RFI pigs in two geographic locations and/or in both ROI batches. These are major contributors to carbohydrate metabolism, which was reflected in functional predictions. Fecal volatile fatty acids and salivary cortisol were the only physiological parameters that differed between RFI ranks. Despite controlling genetics, diet specification, dietary phases, and management practices in each rearing environment, the rearing environment, encompassing maternal influence, herd health status, as well as other factors, appears to impact intestinal microbiota more than FE.IMPORTANCE Interest in the role of intestinal microbiota in determining FE in pigs has increased in recent years. However, it is not known if the same FE-associated bacteria are found across different rearing environments. In this study, geographic location and intestinal sampling site had a greater influence on the pig gut microbiome than FE. This presents challenges when aiming to identify consistent reliable microbial biomarkers for FE. Nonetheless, seven FE-associated microbial taxa were common across two geographic locations and/or two batches within one location, and these indicated a potentially "healthier" and metabolically more capable microbiota in more-feed-efficient pigs. These taxa could potentially be employed as biomarkers for FE, although bacterial consortia, rather than individual taxa, may be more likely to predict FE. They may also merit consideration for use as probiotics or could be targeted by dietary means as a strategy for improving FE in pigs in the future.

Influence of the Intestinal Microbiota on Colonization Resistance to Salmonella and the Shedding Pattern of Naturally Exposed Pigs.

Salmonella colonization and infection in production animals such as pigs are a cause for concern from a public health perspective. Variations in susceptibility to natural infection may be influenced by the intestinal microbiota. Using 16S rRNA compositional sequencing, we characterized the fecal microbiome of 15 weaned pigs naturally infected with Salmonella at 18, 33, and 45 days postweaning. Dissimilarities in microbiota composition were analyzed in relation to Salmonella infection status (infected, not infected), serological status, and shedding pattern (nonshedders, single-point shedders, intermittent-persistent shedders). Global microbiota composition was associated with the infection outcome based on serological analysis. Greater richness within the microbiota postweaning was linked to pigs being seronegative at the end of the study at 11 weeks of age. Members of the Clostridia, such as Blautia, Roseburia, and Anaerovibrio, were more abundant and part of the core microbiome in nonshedder pigs. Cellulolytic microbiota (Ruminococcus and Prevotella) were also more abundant in noninfected pigs during the weaning and growing stages. Microbial profiling also revealed that infected pigs had a higher abundance of Lactobacillus and Oscillospira, the latter also being part of the core microbiome of intermittent-persistent shedders. These findings suggest that a lack of microbiome maturation and greater proportions of microorganisms associated with suckling increase susceptibility to infection. In addition, the persistence of Salmonella shedding may be associated with an enrichment of pathobionts such as Anaerobiospirillum. Overall, these results suggest that there may be merit in manipulating certain taxa within the porcine intestinal microbial community to increase disease resistance against Salmonella in pigs. IMPORTANCE Salmonella is a global threat for public health, and pork is one of the main sources of human salmonellosis. However, the complex epidemiology of the infection limits current control strategies aimed at reducing the prevalence of this infection in pigs. The present study analyzes for the first time the impact of the gut microbiota in Salmonella infection in pigs and its shedding pattern in naturally infected growing pigs. Microbiome (16S rRNA amplicon) analysis reveals that maturation of the gut microbiome could be a key consideration with respect to limiting the infection and shedding of Salmonella in pigs. Indeed, seronegative animals had higher richness of the gut microbiota early after weaning, and uninfected pigs had higher abundance of strict anaerobes from the class Clostridia, results which demonstrate that a fast transition from the suckling microbiota to a postweaning microbiota could be crucial with respect to protecting the animals.

Exploring the roles of and interactions among microbes in dry co-digestion of food waste and pig manure using high-throughput 16S rRNA gene amplicon sequencing.

BACKGROUND: With the increasing global population and increasing demand for food, the generation of food waste and animal manure increases. Anaerobic digestion is one of the best available technologies for food waste and pig manure management by producing methane-rich biogas. Dry co-digestion of food waste and pig manure can significantly reduce the reactor volume, capital cost, heating energy consumption and the cost of digestate liquid management. It is advantageous over mono-digestion of food waste or pig manure due to the balanced carbon/nitrogen ratio, high pH buffering capacity, and provision of trace elements. However, few studies have been carried out to study the roles of and interactions among microbes in dry anaerobic co-digestion systems. Therefore, this study aimed to assess the effects of different inocula (finished digestate and anaerobic sludge taken from wastewater treatment plants) and substrate compositions (food waste to pig manure ratios of 50:50 and 75:25 in terms of volatile solids) on the microbial community structure in food waste and pig manure dry co-digestion systems, and to examine the possible roles of the previously poorly described bacteria and the interactions among dry co-digestion-associated microbes. RESULTS: The dry co-digestion experiment lasted for 120 days. The microbial profile during different anaerobic digestion stages was explored using high-throughput 16S rRNA gene amplicon sequencing. It was found that the inoculum factor was more significant in determining the microbial community structure than the substrate composition factor. Significant correlation was observed between the relative abundance of specific microbial taxa and digesters' physicochemical parameters. Hydrogenotrophic methanogens dominated in dry co-digestion systems. CONCLUSIONS: The possible roles of specific microbial taxa were explored by correlation analysis, which were consistent with the literature. Based on this, the anaerobic digestion-associated roles of 11 bacteria, which were previously poorly understood, were estimated here for the first time. The inoculum played a more important role in determining the microbial community structure than substrate composition in dry co-digestion systems. Hydrogenotrophic methanogenesis was a significant methane production pathway in dry co-digestion systems.