Houttuynia cordata Thunb. extract in pig production: a multifaceted alternative to antibiotics with antimicrobial, antioxidant, and health-promoting properties

Phytobiotics are plant-derived rich in bioactive compounds such as phenolics, organosulfur compounds, terpenes, and aldehydes. Phytobiotics can be classified based on their origin or chemical structure, with the main categories being essential oils, oleoresins, and herbs and spices. Phytobiotics have gained interest due to their positive effects on animal health, including anti-inflammatory, antioxidant, and antimicrobial properties resulting in improved growth performance. This review explores the mode of action of phytobiotics based on their bioactive compounds and highlights their impacts on intestinal health and growth performance in pigs. The inclusion of phytobiotics in pig diets has shown promise in mitigate negative impacts caused by environmental and dietary challenges by reducing inflammatory and oxidative stress responses, enhancing intestinal barrier function, and exhibiting antimicrobial properties against pathogens like Escherichia coli. Collectively, phytobiotics showed a diverse biological activity through different mode of actions, resulting in improved growth performance and overall health in pigs, making phytobiotics a valuable feed additive in pig nutrition and production.

Simple SummaryThe earlier establishment of a health-benefiting intestinal microbiota can be an important strategy to improve intestinal health and subsequent growth performance. Functional oils, such as castor oil and cashew nutshell liquid, have been studied for promoting intestinal health due to their antimicrobial and anti-inflammatory properties. This study aimed to investigate the benefits of supplementation of functional oils on modulation of mucosa-associated microbiota, enhancing the intestinal health and growth performance of nursery pigs. It was demonstrated that the functional oils enhanced the intestinal health of the pigs by increasing beneficial and reducing harmful bacteria and by potentially reducing jejunal oxidative stress and enhancing intestinal morphology. Our results suggest that the blend composed of castor oil and cashew nutshell liquid can be used in nursery pigs to modulate the jejunal mucosa-associated microbiota and intestinal integrity of nursery pigs.This study aimed to investigate the effects of functional oils on modulation of mucosa-associated microbiota, intestinal health, and growth performance of nursery pigs. Forty newly weaned pigs (20 barrows and 20 gilts) with 7.0 ± 0.5 kg body weight (BW) were housed individually and randomly allotted in a randomized complete block design with sex and initial BW as blocks. The dietary treatments were a basal diet with increasing levels (0.00, 0.50, 0.75, 1.00, and 1.50 g/kg feed) of functional oils (a blend of castor oil and cashew nutshell liquid; Oligo Basics USA LLC, Cary, NC) fed to pigs for 34 days divided in two phases (P1 for 13 days and P2 for 21 days). Growth performance was analyzed weekly. On day 34, all pigs were euthanized to collect jejunal mucosa for analyzing the mucosa-associated microbiota and intestinal health, and ileal digesta for analyzing apparent ileal digestibility. Data were analyzed using SAS 9.4. Supplementation of functional oils did not affect the overall growth performance. Increasing supplementation of functional oils reduced (p < 0.05) the relative abundance of Helicobacteraceae, whereas it increased (p < 0.05) Lactobacillus kitasatonis. Supplementation of functional oils tended (p = 0.064) to decrease protein carbonyl and increase the villus height (p = 0.098) and crypt depth (p = 0.070). In conclusion, supplementation of functional oils enhanced intestinal health of nursery pigs by increasing beneficial and reducing harmful bacteria, potentially reducing oxidative stress and enhancing intestinal morphology, without affecting overall growth performance of pigs. Supplementation of functional oils at 0.75–1.50 g/kg feed was the most beneficial to the jejunal mucosa-associated microbiota and intestinal integrity of nursery pigs.

The objective of this study was to evaluate phytogenic formulations on intestinal health and growth performance of nursery pigs challenged with F18+Escherichia coli. Weaned pigs [n = 40; initial body weight (BW) = 6.4 ± 0.1 kg] at 21 d of age were individually housed and assigned to 4 dietary treatments in a randomized complete block design, with initial BW and sex as blocking factors. Basal diets were formulated following NRC (2012) and fed to pigs for 28 d in 3 phases (P1:11 d, P2:10 d and P3:7 d). Treatments were NC: basal diet, non-challenge; PC: basal diet, challenged with F18+E. coli; AV1: basal diet supplemented with 1% phytobiotic containing herbal extracts and essential oils in powder form, challenged with F18+E. coli; AV2: basal diet + 1% phytobiotic containing herbal extracts and essential oils in liquid form, challenged with F18+E. coli. Growth performance and fecal score (FS) were measured weekly. On d 7, the challenged groups were orally inoculated with F18+E. coli (2.0 × 1010), whereas unchallenged pigs received a sterile saline solution. On d 28, all pigs were euthanized to collect jejunal samples to evaluate inflammatory status, oxidative stress, and diversity and relative abundance of mucosa-associated microbiota. Data were analyzed using the MIXED procedure on SAS 9.4. During the post-challenge period, PC decrease (P &amp;lt; 0.05) average daily gain (ADG) and average daily feed intake (ADFI) when compared with NC. The PC increased (P &amp;lt; 0.05) FS during d 7 to 11 when compared with NC, whereas AV1 and AV2 decreased (P &amp;lt; 0.05) FS during d 7 to 11 when compared with PC. The AV1 decreased (P &amp;lt; 0.05) Chao1 and Shannon indexes when compared with PC. The PC increased (P &amp;lt; 0.05) the relative abundance of Prevotellaceae, Lachnospiraceae, and Ruminococcaceae compared with NC. The AV1 reduced (P &amp;lt; 0.05) the relative abundance of Veillonellaceae, Prevotellaceae, Lachnospiraceae and tended to reduce (P = 0.062) the relative abundance of Ruminococcaceae when compared with PC. The AV2 tended to reduce the relative abundance of Streptococcaceae (P = 0.073) and Ruminococcaceae (P = 0.074) when compared with PC. The PC increased (P &amp;lt; 0.05) occludin and tended to increase (P = 0.096) TLR4 when compared with NC. The AV1 tended to increase (P = 0.053) protein carbonyl when compared with PC. In conclusion, F18+E. coli challenge increased FS, disrupted the mucosa-associated microbiota, increased TLR4 expression, consequently reduced growth performance of pigs. The AV1 showed promise in reducing oxidative stress during F18+E. coli challenge, seen through decreased protein carbonyl levels possibly due to alterations on mucosa-associated microbiota, although without affecting growth performance. The AV2 had a moderate impact on reducing FS and altering mucosa-associated microbiota, without effect on growth performance.

Improving the attitude and behaviour of stockpersons towards pigs and the consequences on the behaviour and reproductive performance of commercial pigs

An important task is to increase the efficiency of pig-breeding. Breeding to improve the reproductive qualities of sows will improve their reproductive performance and increase the volume of production. In this regard, the search for genetic variants associated with reproductive performance of pigs is of particular relevance and scientific importance. The aim of the study was to evaluate the effect of TMEM132D gene on reproductive performance of large white pigs and to consider it as a genetic marker for selection and breeding work.

Acid-binding capacity of feed in swine nutrition

The objective of this research was to investigate the functional roles of phytase and xylanase in nursery pigs and broiler chickens. These enzymes have been widely studied and have shown consistent results improving nutrient digestibility and growth performance. However, recent studies have raised the hypothesis that phytase and xylanase could also have potential effects on intestinal and bone health, and intestinal microbiota. The first study studied at the effects of a bacterial 6-phytase on nutrient digestibility and retention of nursery and growing pigs. The results showed that supplementing a bacterial 6-phytase in pig diets can be a potential alternative for reducing high levels of inorganic phosphorus sources while still increasing the digestibility and utilization of phosphorus by the animals. The second study investigated the efficacy and optimal level of a bacterial 6-phytase supplemented beyond traditional dose levels on bone and intestinal health, nutrient digestibility, and growth performance of nursery pigs. The results revealed that the supplementation of the bacterial 6-phytase enhanced bone health, nutrient digestibility, and growth performance in nursery pigs. The third study aimed to determine the effects of phytase supplementation on the intestinal microbiota and morphology, bone health, nutrient digestibility, and growth performance of broiler chickens. The results showed that phytase supplementation had potential benefits on the microbiota by reducing potential harmful bacteria and increasing beneficial bacteria. Additionally, phytase had positive effects on bone health, intestinal morphology, and nutrient digestibility of broiler chickens. The fourth study examined the functional roles of xylanase on the intestinal health and growth performance of nursery pigs. The results showed that xylanase supplementation had beneficial effects on intestinal health by reducing the digesta viscosity, the relative abundance of potentially harmful bacteria, and the oxidative stress in the jejunal mucosa. All of these factors collectively reflected in improvements on the intestinal morphology, nutrient digestibility, and growth performance of nursery pigs. In conclusion, the results of these studies reaffirmed the benefits of phytase and xylanase related to nutrient digestibility and growth performance in nursery pigs and broiler chickens, as well as showed potential benefits on intestinal health and microbiota of the animals. Supplementing these enzymes could also contribute to a reduction in feed costs and environmental concerns associated with a poor hydrolysis and breakdown of antinutritional factors in animal diets.

Feed is the most expensive input in commercial pork production. In order to reduce feed costs, using high-fiber ingredients has become a common practice. Moderate levels of fiber can maintain intestinal physiological function and promote intestinal health. Oxidative stress is linked to impaired nutrient absorption and growth performance. This study investigated the effects of high-fiber (HF, 6% crude fiber) and low-fiber (LF, 3% crude fiber) diets on growth performance and intestinal oxidative stress parameters in growing-finishing pigs. Forty growing pigs (27.07 ± 1.26 kg BW) were randomly assigned to 2 treatments with 10 replicates of 2 pigs per pen. Pigs were weighed on days 35, 42 and 70. The feed intake was recorded daily to calculate growth performance parameters. On day 70, eight pigs in each treatment group were randomly selected and euthanized to obtain jejunum to measure oxidative stress status. Pigs fed an HF diet were heavier than those fed an LF diet on days 35, 42 and 70 (P &amp;lt; 0.05). During the whole feeding period, pigs fed an HF diet had higher average daily gain than those fed an LF diet (P &amp;lt; 0.05). The LF diet resulted in increased levels of malondialdehyde (P &amp;lt; 0.05) in the jejunum, suggesting that the LF diet contributed to oxidative stress in the jejunum. The LF diet also led to a significant increase in glutathione and oxidized glutathione levels (P &amp;lt; 0.05) in the jejunum, indicating that pigs fed an LF diet needed to produce more antioxidant substances to cope with oxidative stress in the intestine. This was accompanied by a significant increase in glutamate-cysteine ligase in the jejunum of the LF group (P &amp;lt; 0.05). These results suggest that the HF diet can improve growth performance and maintain intestinal health in growing-finishing pigs by reducing intestinal oxidative stress.

Due to the restrictions on the use of antibiotics in animal husbandry as growth promoters, scientific interest in natural biologically active substances has significantly increased, with essential oils (EOs) and phytogenic preparations occupying a prominent place. The aim of this study is to systematize current data on the immunotropic, antimicrobial, and antioxidant effects of essential oils on productive and reproductive performance of pigs, calves, and poultry, as well as to assess their potential as a safe alternative to antibiotics and growth stimulators. Literature analysis has shown that EOs from plants such as oregano, thyme, cinnamon, rosemary, garlic, and chili pepper contain biologically active compounds (carvacrol, thymol, cinnamaldehyde, eugenol) that provide a broad spectrum of antimicrobial activity against Gram-positive and Gram-negative bacteria, fungi, and yeasts. It has been established that the use of EOs in pig farming improves intestinal microbial balance, reduces the incidence of gastrointestinal disorders in piglets, increases average daily weight gain, improves feed conversion, and enhances meat quality. In calves, EOs increase feed intake, stabilize rumen microflora, reduce diarrhea occurrence, and improve nutrient digestibility, thereby enhancing growth energy. In poultry, EOs optimize broiler growth, improve feed digestibility, support the immune system, and enhance carcass quality. The antioxidant action of essential oils protects tissues from oxidative stress, reduces the formation of lipid peroxidation products (MDA, TBARS), and helps maintain meat quality during storage. Additionally, EOs stimulate digestive enzyme secretion, enhance the protective properties of the intestinal mucosa, prevent pathogen adhesion, and stabilize beneficial microbiota, positively affecting animal productivity and immunity. Thus, essential oils and phytogenic preparations are promising functional components in sustainable animal husbandry systems, allowing for increased productivity and product quality without the risk of developing resistance or the side effects associated with antibiotics.

Starch from cereal grains, pulse grains, and tubers is a major energy substrate in swine rations constituting up to 55% of the diet. In pigs, starch digestion is initiated by salivary and then pancreatic α-amylase, and has as final step the digestion of disaccharides by the brush-border enzymes in the small intestine that produce monosaccharides (glucose) for absorption. Resistant starch (RS) is the proportion of starch that escapes the enzymatic digestion and absorption in the small intestine. The undigested starch reaches the distal small intestine and hindgut for microbial fermentation, which produces short-chain fatty acids (SCFA) for absorption. SCFA in turn, influence microbial ecology and gut health of pigs. These fermentative metabolites exert their benefits on gut health through promoting growth and proliferation of enterocytes, maintenance of intestinal integrity and thus immunity, and modulation of the microbial community in part by suppressing the growth of pathogenic bacteria while selectively enhancing beneficial microbes. Thus, RS has the potential to confer prebiotic effects and may contribute to the improvement of intestinal health in pigs during the post-weaning period. Despite these benefits to the well-being of pigs, RS has a contradictory effect due to lower energetic efficiency of fermented vs. digested starch absorption products. The varying amount and type of RS interact differently with the digestion process along the gastrointestinal tract affecting its energy efficiency and host physiological responses including feed intake, energy metabolism, and feed efficiency. Results of research indicate that the use of RS as prebiotic may improve gut health and thereby, reduce the incidence of post-weaning diarrhea (PWD) and associated mortality. This review summarizes our current knowledge on the effects of RS on microbial ecology, gut health and growth performance in pigs.

Feed-grade antibiotics in pig production were used to not only treat and prevent disease, but to promote growth as well, with improvements in ADG of up to 16% and F:G of up to 6% in nursery pigs common. However, these uses may contribute to antibiotic-resistant microbes that negatively affect human and animal health, and the swine industry seeks alternatives. OmniGen-AF (Phibro Animal Health, Teaneck, NJ; OG), a blend of vitamins, minerals, and microbial ingredients is a dietary immuno-modulator used to support immune function and reduce the negative effects of stressors in dairy cattle. Weaning is inherently stressful to pigs. There are limited data, however, on the effects of OG on growth and well-being in swine. The objective was to determine the effect of dietary supplementation with OG on growth performance in 21-day-old weaned pigs. Barrows (n = 36) and gilts (n = 36) were blocked by weight, and placed in sex-specific pens of three pigs each. Within blocks, pens were assigned to ad libitum access to OG (4 g/45.4 kg∙BW-1ּּּ ∙day-1) or control diets in a 2 x 2 factorial arrangement. The factors consisted of sex and presence or absence of OG in the diets of a three-phase feeding regimen. There were 6 replicate pens per sex and dietary treatment combination. Compared with gilts, barrows were heavier (effect of sex, P &amp;lt; 0.01), and across diets pigs showed an increase in BW during the 42-d trial (effect of day, P &amp;lt; 0.01). There were no effects (P &amp;gt; 0.10) of diet, or diet by sex on growth performance (ADG, 0.86 vs. 0.84 kg, SE = 0.05; ADFI, 1.42 vs. 1.41 kg, SE = 0.07; and, F:G, 1.66 vs. 1.69, SE = 0.03, for OG and CON, respectively). Fecal consistency scores (1 to 5; 1 = exceptionally firm, 5 = very loose and watery) were affected by day (P &amp;lt; 0.01), increasing (P = 0.02) from day 0 (3.00 ± 0.07) to a peak on day 4 (3.29 ± 0.07), before decreasing to values on d 35 (3.00 ± 0.07) and 42 (3.00 ± 0.07) that were not different from values on day 0. There were no effects (P &amp;gt; 0.32) of diet or sex on scores. No pig deaths occurred during the experiment. In this study, dietary supplementation with OG did not affect growth performance in pigs. The experiment, however, was conducted in a clean, highly managed University facility, and overall pig health appeared excellent as indicated by daily observations, fecal consistency scores, and no mortality occurring during the study. In this situation, it would be difficult to show a positive effect of a feed additive because the pigs were perhaps already performing at or near their genetic potential.

In recent years, the emphasis on reproductive performance in pigs has increased, although the favourable impact of improving reproductive performance on the overall efficiency of production has long been recognised. There is widespread agreement that increasing the number of pigs per sow per year should be a major objective of the pig industry, particularly as limits in fat reduction are approached. The 1994 British Society of Animal Science Braude Scholarship was used to investigate current research in the area of swine reproduction and identify particular areas of concern as perceived by the North American pig industry. The main objectives of the scholarship were to (1) present a paper at the Fifth World Congress on Genetics Applied to Livestock Production (2) visit research establishments in the USA to discuss current research projects in pigs, with particular emphasis on genetic variation in reproduction traits and (3) visit major pig breeding companies in the USA to discuss the application of research results in modern pig breeding programmes and the required future research.

This review is focused on studies of vitamin E in immunity and reproductive performance in pigs. There are reports that vitamin E can have a positive effect on some parameters of the immune system in pigs. The optimal level of vitamin E needed to improve the immune system has not been determined because of several factors such as the composition of the diet, feed consumption, the rate of animal growth and living conditions or stress. Moreover, the way of action of vitamin E in enhancing immunity is still unclear but according to reports it may have antioxidant properties as well as an immunomodulator effect. In several studies, an increase in litter size and a reduction of preweaning piglet mortality have resulted from increasing dietary vitamin E intake during gestation or by intramuscular injection of vitamin E and/or selenium. However, according to reports, the positive effect of vitamin E on reproductive performance remains unclear due to the low number of animals used in most experiments.

In recent years, the emphasis on reproductive performance in pigs has increased, although the favourable impact of improving reproductive performance on the overall efficiency of production has long been recognised. There is widespread agreement that increasing the number of pigs per sow per year should be a major objective of the pig industry, particularly as limits in fat reduction are approached. The 1994 British Society of Animal Science Braude Scholarship was used to investigate current research in the area of swine reproduction and identify particular areas of concern as perceived by the North American pig industry. The main objectives of the scholarship were to (1) present a paper at the Fifth World Congress on Genetics Applied to Livestock Production (2) visit research establishments in the USA to discuss current research projects in pigs, with particular emphasis on genetic variation in reproduction traits and (3) visit major pig breeding companies in the USA to discuss the application of research results in modern pig breeding programmes and the required future research.

This study was conducted to investigate the functional roles of an endo-β-1,4-xylanase on the intestinal health and growth performance of nursery pigs. A total of 60 pigs (21 d old, 6.9 ± 0.8 kg body weight [BW]) were allotted based on a randomized complete block design with sex and initial BW as blocks. Dietary treatments had nutrients meeting the requirements with increasing levels of endo-β-1,4-xylanase (0, 220, 440, 880, 1,760 xylanase unit [XU] per kg feed) and fed to pigs in three phases (phases 1, 2, and 3 for 10, 14, and 14 d, respectively). Titanium dioxide (0.4%) was added to the phase 3 diets as an indigestible marker. On day 38, all pigs were euthanized to collect ileal digesta to measure apparent ileal digestibility (AID), jejunal digesta to measure viscosity, and jejunal mucosa to evaluate intestinal health. Data were analyzed using the MIXED procedure for polynomial contrasts and the NLMIXED procedure for broken line analysis of SAS. Increasing xylanase in the nursery diets reduced (linear, P < 0.05) the digesta viscosity in the jejunum. Increasing xylanase tended to reduce the relative abundance of Cupriavidus (P = 0.073) and Megasphaera (P = 0.063); tended to increase the relative abundance of Succinivibrio (P = 0.076) and Pseudomonas (P = 0.060); and had a quadratic effect (P < 0.05) on the relative abundance of Acinetobacter (maximum: 2.01% at 867 XU per kg feed). Xylanase from 0 to 1,087 XU per kg feed reduced (P < 0.05) jejunal malondialdehyde. Xylanase from 0 to 1,475 XU per kg feed increased (P < 0.05) the AID of neutral detergent fiber. Increasing xylanase increased (P < 0.05) the AID of ether extract and tended to increase (P = 0.058) the AID of crude protein. Increasing xylanase did not affect growth performance on overall period, whereas xylanase from 0 to 736 XU per kg feed increased (P < 0.05) average daily gain (ADG) during days 31 to 38. In conclusion, xylanase supplementation showed benefits on intestinal health by reducing digesta viscosity, the relative abundance of potentially harmful bacteria, and the oxidative stress in the jejunal mucosa, collectively enhancing intestinal morphology and the AID of nutrients. Xylanase supplementation at a range of 750 to 1,500 XU per kg feed provided benefits associated with reduced oxidative stress, increased nutrient digestibility, resulting in potential improvement on growth performance of nursery pigs by increasing the average daily feed intake and moderately improving the ADG throughout the last week of feeding.