Effects of Yarrowia lipolytica supplementation on growth performance, intestinal health and apparent ileal digestibility of diets fed to nursery pigs

Development and application of a multi-step porcine in vitro system to evaluate feedstuffs and feed additives for their efficacy in nutrient digestion, digesta characteristics, and intestinal immune responses

In vitro model provides alternatives to the use of live animals in research. In pig nutrition, there has been a tremendous increase in in vivo research over the decades. Proper utilization of in vitro models could provide a screening tool to reduce the needs of in vivo studies, research duration, cost, and the use of animals and feeds. This study aimed to develop a multi-step porcine in vitro system to simulate nutrient digestion and intestinal epithelial immune responses affected by feedstuffs and feed additives. Seven feedstuffs (corn, corn distillers dried grains with solubles [corn DDGS], barley, wheat, soybean meal, soy protein concentrates, and Corynebacterium glutamicum cell mass [CGCM]), feed enzymes (xylanase and phytase), and supplemental amino acids (arginine, methionine, and tryptophan), were used in this in vitro evaluation for their efficacy on digestibility, digesta characteristics, and intestinal health compared with the results from previously published in vivo studies. All in vitro evaluations were triplicated. Data were analyzed using Mixed procedure of SAS9.4. Evaluations included (1) nutrient digestibility of feedstuffs, (2) the effects of feed enzymes, xylanase and phytase, on digestibility of feedstuffs and specific substrates, and (3) the effects of amino acids, arginine, tryptophan, and methionine, on anti-inflammatory, anti-oxidative, and anti-heat stress statuses showing their effects (P < 0.05) on the measured items. Differences in dry matter and crude protein digestibility among the feedstuffs as well as effects of xylanase and phytase were detected (P < 0.05), including xylo-oligosaccharide profiles and phosphorus release from phytate. Supplementation of arginine, tryptophan, and methionine modulated (P < 0.05) cellular inflammatory and oxidative stress responses. The use of this in vitro model allowed the use of 3 experimental replications providing sufficient statistical power at P < 0.05. This indicates in vitro models can have increased precision and consistency compared with in vivo animal studies.

Comparative effects of soy protein concentrate, enzyme-treated soybean meal, and fermented soybean meal replacing animal protein supplements in feeds on growth performance and intestinal health of nursery pigs

BACKGROUND

Soy protein supplements, with high crude protein and less antinutritional factors, are produced from soybean meal by different processes. This study evaluated the comparative effects of various soy protein supplements replacing animal protein supplements in feeds on the intestinal immune status, intestinal oxidative stress, mucosa-associated microbiota, and growth performance of nursery pigs.

METHODS

Sixty nursery pigs (6.6 ± 0.5 kg BW) were allotted to five treatments in a randomized complete block design with initial BW and sex as blocks. Pigs were fed for 39 d in 3 phases (P1, P2, and P3). Treatments were: Control (CON), basal diet with fish meal 4%, 2%, and 1%, poultry meal 10%, 8%, and 4%, and blood plasma 4%, 2%, and 1% for P1, P2, and P3, respectively; basal diet with soy protein concentrate (SPC), enzyme-treated soybean meal (ESB), fermented soybean meal with Lactobacillus (FSBL), and fermented soybean meal with Bacillus (FSBB), replacing 1/3, 2/3, and 3/3 of animal protein supplements for P1, P2, and P3, respectively. Data were analyzed using the MIXED procedure in SAS 9.4.

RESULTS

The SPC did not affect the BW, ADG, and G:F, whereas it tended to reduce (P = 0.094) the ADFI and tended to increase (P = 0.091) crypt cell proliferation. The ESM did not affect BW, ADG, ADFI, and G:F, whereas tended to decrease (P = 0.098) protein carbonyl in jejunal mucosa. The FSBL decreased (P < 0.05) BW and ADG, increased (P < 0.05) TNF-α, and Klebsiella and tended to increase MDA (P = 0.065) and IgG (P = 0.089) in jejunal mucosa. The FSBB tended to increase (P = 0.073) TNF-α, increased (P < 0.05) Clostridium and decreased (P < 0.05) Achromobacter and alpha diversity of microbiota in jejunal mucosa.

CONCLUSIONS

Soy protein concentrate, enzyme-treated soybean meal, and fermented soybean meal with Bacillus could reduce the use of animal protein supplements up to 33% until 7 kg body weight, up to 67% from 7 to 11 kg body weight, and entirely from 11 kg body weight without affecting the intestinal health and the growth performance of nursery pigs. Fermented soybean meal with Lactobacillus, however, increased the immune reaction and oxidative stress in the intestine consequently reducing the growth performance.

Intestinal Damages by F18+Escherichia coli and Its Amelioration with an Antibacterial Bacitracin Fed to Nursery Pigs

This study investigated intestinal oxidative damage caused by F18⁺Escherichia coli and its amelioration with antibacterial bacitracin fed to nursery pigs. Thirty-six weaned pigs (6.31 ± 0.08 kg BW) were allotted in a randomized complete block design. Treatments were: NC, not challenged/not treated; PC, challenged (F18⁺E. coli at 5.2 × 10⁹ CFU)/not treated; AGP challenged (F18⁺E. coli at 5.2 × 10⁹ CFU)/treated with bacitracin (30 g/t). Overall, PC reduced (p < 0.05) average daily gain (ADG), gain to feed ratio (G:F), villus height, and villus height to crypt depth ratio (VH:CD), whereas AGP increased (p < 0.05) ADG, and G:F. PC increased (p < 0.05) fecal score, F18⁺E. coli in feces, and protein carbonyl in jejunal mucosa. AGP reduced (p < 0.05) fecal score and F18⁺E. coli in jejunal mucosa. PC reduced (p < 0.05) Prevotella stercorea populations in jejunal mucosa, whereas AGP increased (p < 0.05) Phascolarctobacterium succinatutens and reduced (p < 0.05) Mitsuokella jalaludinii populations in feces. Collectively, F18⁺E. coli challenge increased fecal score and disrupted the microbiota composition, harming intestinal health by increasing oxidative stress, and damaging the intestinal epithelium, ultimately impairing growth performance. Dietary bacitracin reduced reduced F18⁺E. coli populations and the oxidative damages they cause, thereby improving intestinal health and the growth performance of nursery pigs.

The effects of standardized ileal digestible His to Lys ratio on growth performance, intestinal health, and mobilization of histidine-containing proteins in pigs at 7 to 11 kg body weight

The objectives were to evaluate the effects of standardized ileal digestible (SID) His:Lys ratio above the current NRC requirement on growth performance, intestinal health, and mobilization of His-containing proteins, including hemoglobin, carnosine, and trypsinogen, in nursery pigs from 7 to 11 kg body weight (BW). Forty pigs (26 d of age; initial BW of 7.1 ± 0.5 kg) were allotted to 5 dietary treatments based on a randomized complete block design with sex and initial BW as blocks. Dietary treatments were supplemented with varying SID His to Lys ratios of 26%, 32%, 38%, 43%, and 49% and fed to pigs for 14 d (SID Lys = 1.22%). Feed intake and BW were recorded at d 0, 7, and 14 to measure growth performance. Blood samples were collected on d 12. Pigs were euthanized on d 14 to collect pancreas, longissimus dorsi muscles, mid-jejunum, and jejunal mucosa. Data were analyzed using the Proc Mixed of SAS. Growth performance was not affected, whereas varying SID His to Lys ratio affected hemoglobin (P < 0.05, max: 12 g/dL at 36%), immunoglobulin A (IgA, P < 0.05, min: 1.25 μg/mg at 35%) in jejunal mucosa, villus height (P = 0.065, max: 536 μm at 40%) in jejunum, trypsinogen (P = 0.083, max: 242 pg/mg at 41%) in pancreas, and carnosine (P = 0.051, max: 4.7 ng/mg at 38%) in muscles. Varying SID His to Lys ratios linearly increased (P < 0.05, from 1.95 to 2.80 nmol/mg) protein carbonyl in muscles and decreased (P < 0.05, from 29.1% to 26.9%) enterocyte proliferation. In conclusion, SID His to Lys ratio between 35% and 41% in diets fed to nursery pigs at 7 to 11 kg enhanced intestinal health and maximized concentrations of His-containing proteins, indicating that His-containing proteins are effective response criteria when determining His requirement.

Efficacy of a bacterial 6-phytase supplemented beyond traditional dose levels on jejunal mucosa-associated microbiota, ileal nutrient digestibility, bone parameters, and intestinal health, and growth performance of nursery pigs

This study aimed to determine the efficacy of a bacterial 6-phytase (Buttiauxella spp.) supplemented beyond traditional dose levels based on jejunal mucosa-associated microbiota, apparent ileal digestibility (AID), intestinal health and bone parameters, and growth performance of nursery pigs. Seventy-two weaned pigs (36 barrows and 36 gilts at 21 d of age with 5.8 ± 0.5 kg BW) were allotted to six treatments based on randomized complete block design with sex and initial BW as blocks and fed in three dietary phases (phase 1 for 14 d, phase 2 for 10 d, and phase 3 for 14 d). The treatments included a negative control (NC) diet without phytase formulated meeting nutrient requirements by NRC and the other five treatments were deficient in calcium (Ca) and phosphorus (P) by 0.12% with increasing levels of a bacterial 6-phytase (0, 500, 1,000, 2,000, and 5,000 FTU/kg feed). Titanium dioxide (0.4%) was added to phase 3 diets as an indigestible marker to measure AID of nutrients. On day 45, all pigs were euthanized to collect ileal digesta to measure AID, the third metacarpus to measure bone parameters, and jejunal mucosa to evaluate intestinal health and microbiota. Data were analyzed using the MIXED procedure for polynomial contrasts and the NLMIXED procedure for broken line analysis using the SAS 9.4. Broken line analysis demonstrated that 948 FTU/kg feed increased (P < 0.05) the ADG and the bone P content. Increasing phytase supplementation increased (linear, P < 0.05) AID of CP, bone P, and ash content. Increasing phytase supplementation reduced (P < 0.05) the fecal score during phases 2 and 3. Broken line analysis demonstrated that 1,889 FTU/kg feed increased (P < 0.05) bone breaking strength. Increasing phytase supplementation (PC vs. Phy) increased (P < 0.05) AID of ether extract (EE) and P. The supplementation of phytase at 2,000 FTU/kg feed tended (P = 0.087) to reduce the relative abundance of Prevotellaceae. In conclusion, the supplementation of a bacterial 6-phytase beyond traditional dose levels improved bone breaking strength, bone ash, and P content, AID of CP, EE, and P, and growth performance of nursery pigs with reduced relative abundance of Bacteroidetes specifically Prevotellaceae in the jejunal mucosa. Supplementation of a bacterial 6-phytase between 1,000 and 2,000 FTU/kg feed provided benefits associated with growth performance and bone parameters of nursery pigs.

Nutritional and Functional Roles of Phytase and Xylanase Enhancing the Intestinal Health and Growth of Nursery Pigs and Broiler Chickens

This review paper discussed the nutritional and functional roles of phytase and xylanase enhancing the intestinal and growth of nursery pigs and broiler chickens. There are different feed enzymes that are currently supplemented to feeds for nursery pigs and broiler chickens. Phytase and xylanase have been extensively studied showing consistent results especially related to enhancement of nutrient digestibility and growth performance of nursery pigs and broiler chickens. Findings from recent studies raise the hypothesis that phytase and xylanase could play functional roles beyond increasing nutrient digestibility, but also enhancing the intestinal health and positively modulating the intestinal microbiota of nursery pigs and broiler chickens. In conclusion, the supplementation of phytase and xylanase for nursery pigs and broiler chickens reaffirmed the benefits related to enhancement of nutrient digestibility and growth performance, whilst also playing functional roles benefiting the intestinal microbiota and reducing the intestinal oxidative damages. As a result, it could contribute to a reduction in the feed costs by allowing the use of a wider range of feedstuffs without compromising the optimal performance of the animals, as well as the environmental concerns associated with a poor hydrolysis of antinutritional factors present in the diets for swine and poultry.

Use of Microorganisms as Nutritional and Functional Feedstuffs for Nursery Pigs and Broilers

The objectives of this review paper are to introduce the structures and composition of various microorganisms, to show some applications of single cells as alternative protein supplements or energy feeds in swine and poultry diets, and to discuss the functional effects of microorganisms as feed additives on the growth performance and intestinal health of nursery pigs and broilers. Microorganisms, including bacteria, yeasts, and microalgae, have been commonly supplemented in animal diets because they are cost-effective, stable, and have quantitative production that provides nutritional and functional benefits to pigs and broilers. Microorganisms could be alternative antibiotics to enhance intestinal health due to bioactive components from cell wall components, which interact with receptors on epithelial and immune cells. In addition, bioactive components could be digested by intestinal microbiota to produce short-chain fatty acids and enhance energy utilization. Otherwise, microorganisms such as single-cell protein (SCP) and single-cell oils (SCOs) are sustainable and economic choices to replace conventional protein supplements and energy feeds. Supplementing microorganisms as feedstuffs and feed additives improved the average daily gain by 1.83%, the daily feed intake by 0.24%, and the feed efficiency by 1.46% in pigs and broilers. Based on the properties of each microorganism, traditional protein supplements, energy feeds, and functional feed additives could be replaced by microorganisms, which have shown benefits to animal's growth and health. Therefore, specific microorganisms could be promising alternatives as nutritional and functional feedstuffs in animal diets.

Phytobiotics from Oregano Extracts Enhance the Intestinal Health and Growth Performance of Pigs

This study aimed to investigate the effects of phytobiotics on the intestinal health and growth performance of pigs. Totals of 40 newly-weaned pigs with 6.4 ± 0.3 kg BW (Exp. 1) and 120 growing pigs with 27.9 ± 2.3 kg BW (Exp. 2) were allotted in RCBD in a 2 × 2 factorial arrangement. The factors were: antibiotics as growth promoter (AGP) and phytobiotics (PHY). Pigs were fed experimental diets during 21 d (Exp. 1) and 42 d (Exp. 2). Growth performance, health parameters, and nutrient digestibility were evaluated. In Exp. 1, AGP diet increased (p < 0.05) ADG and G:F compared with a diet without AGP or PHY and a diet with AGP combined with PHY. PHY decreased (p < 0.05) TNF-α and IgG in the jejunum and protein carbonyl in plasma, whereas it increased (p < 0.05) the villus height. In Exp. 2, AGP or PHY diets increased (p < 0.05) ADG, ADFI, and G:F compared with a diet without AGP or PHY and a diet with AGP combined with PHY. PHY decreased (p < 0.05) IgG and PC in plasma. Collectively, AGP and PHY improved growth performance by reducing oxidative stress and enhancing immune status and jejunal morphology. However, the combinational use of phytobiotics with antibiotics suppressed their effect.