In vitro effects of phytogenic feed additive on Piscirickettsia salmonis growth and biofilm formation.

Piscirickettsiosis is the main cause of mortality in salmonids of commercial importance in Chile, which is caused by Piscirickettsia salmonis, a Gram-negative, γ-proteobacteria that can produce biofilm as one of its virulence factors. The Chilean salmon industry uses large amounts of antibiotics to control piscirickettsiosis outbreaks, which has raised concern about its environmental impact and the potential to induce antibiotic resistance. Thus, the use of phytogenic feed additives (PFA) with antibacterial activity emerges as an interesting alternative to antimicrobials. Our study describes the antimicrobial action of an Andrographis paniculate-extracted PFA on P. salmonis planktonic growth and biofilm formation. We observed complete inhibition of planktonic and biofilm growth with 500 and 400 µg/mL of PFA for P. salmonis LF-89 and EM-90-like strains, respectively. Furthermore, 500 µg/mL of PFA was bactericidal for both evaluated bacterial strains. Sub-inhibitory doses of PFA increase the transcript levels of stress (groEL), biofilm (pslD), and efflux pump (acrB) genes for both P. salmonis strains in planktonic and sessile conditions. In conclusion, our results demonstrate the antibacterial effect of PFA against P. salmonis in vitro, highlighting the potential of PFA as an alternative to control Piscirickettsiosis.

Assessing the potential of phytogenic feed additives: A comprehensive review on their effectiveness as a potent dietary enhancement for nonruminant in swine and poultry.

Phytogenic feed additives (PFAs) often referred to as phytobiotics or botanical feed additives, are natural compounds derived from various plants, herbs, spices and other botanical sources. These feed additives are intended to serve a variety of purposes, including an immune system regulator, an antimicrobial, an antimutagenic, an antioxidant and a growth promoter. They are composed of bioactive compounds extracted from plants, including essential oils, polyphenols, terpenoids and flavonoids. They are mostly utilized as substitute antibiotic growth promoters in nonruminant (swine and poultry) livestock production, owing to the prohibition of antibiotic usage in the feed industry. It has been thoroughly examined to ascertain their impact on intestinal health and activity, correlation with animals' effective health and well-being, productivity, food security and environmental impact. The potential uses of these feed additives depend on the properties of herbs, the comprehension of their principal and secondary components, knowledge of their mechanisms of action, the safety of animals and the products they produce. They are gaining recognition as effective and sustainable tools for promoting animal health and performance while reducing the reliance on antibiotics in nonruminant nutrition. Their natural origins, multifaceted benefits and alignment with consumer preferences make them a valuable addition to modern animal farming process. However, because of their inconsistent effects and inadequate knowledge of the mechanisms of action, their usage as a feed additive has been limited. This review offers a comprehensive assessment of the applications of PFAs as an effective feed supplement in swine and poultry nutrition. In summary, this comprehensive review provides current knowledge, identifies gaps in research and emphasizes the potential of phytogenic additives to foster sustainable and healthier livestock production systems while addressing the global concerns associated with antibiotic use in livestock farming.

Navel orange peel hydroethanolic extract as a phytogenic feed supplement: impacts on growth, feed intake, nutrient digestibility, and serum metabolites of heat stressed growing rabbits.

Currently, using agricultural wastes in animal production has gained worldwide interest. Hence, herein, an eight-week trial was performed to explore the effects of supplemental navel orange peel extract (NPE) on the growth, feed utilization, nutrient digestibility, antioxidant, and hematological parameters of heat-stressed rabbits. In total, 75 weaned rabbits were randomly assigned into five groups. The first group was reared in the winter (mild weather) and fed an untreated pelleted diet (W-NPE-0; control). The other four groups were reared in the summer (hot climate) and fed the control diet fortified with 0 (S-NPE-0), 250 (S-NPE-250), 500 (S-NPE-500), or 1000 (S-NPE-1000) mg NPE/kg diet. The results indicated that thermal-stressed rabbits (S-NPE-0) had significantly lower feed intake, growth performance, hematological indices, serum lipid profile, and antioxidative status, but higher lipid peroxidation compared to the W-NPE-0 group. However, the highest final weight and feed intake were recorded in the S-NPE-1000 group compared with the S-NPE-0 group. Also, supplemental NPE in the growing rabbit diet, especially the S-NPE-1000 group, enhanced the hematological and antioxidative indicators. In conclusion, NPE supplementation in growing rabbit diets could be used to efficiently mitigate the detrimental effects of chronic temperature stress on performance, hematobiochemical features, and oxidative stability.

Dietary supplementation of low levels of unprocessed Mucuna pruriens utilis seed meal induces mild antinutritional entero-physio-metabolic perturbations without compromising performance and meat quality in finisher broilers.

The rapidly growing world human population accentuates the need for improved production especially of protein-rich food. Broiler meat production offers opportunity to ensure security of this food. However, the production of modern broilers is not only limited by high feed costs due to dietary use of expensive energy and protein sources but also their meat possesses undesirable quality attributes. This study thus examined the effect of dietary Mucuna pruriens utilis seed meal (MSM) on growth performance, blood profile, carcass traits, and meat quality in finisher broiler chickens. In a completely randomised design (CRD), 320 21-day-old chicks were randomly allocated to 32 pens in which they were allotted 4 dietary treatments with 0, 2.5, 5, and 10% MSM, each with 8 replicate pens of 10 birds, for 28 days. Growth performance, carcass characteristics, internal organs, haemato-biochemistry, and meat quality were measured. Results showed that dietary MSM did not affect (P > 0.05) broiler performance, weights, and lengths of carcass cuts and internal organs, haematology, and meat quality. The only exception was MSM-induced increase in duodenal weight (linear, P < 0.05) and serum phosphorus (quadratic, P = 0.05) in contrast to a decrease in procalcitonin (quadratic, P < 0.01) and serum levels of total protein (linear, P < 0.05; and quadratic, P < 0.01), albumin (quadratic, P < 0.05), and bilirubin (quadratic, P = 0.001). Therefore, MSM could be supplemented up to 10% without compromising performance, carcass traits, internal organs, haemato-biochemistry, and meat quality in finisher broiler diets.

Changes in fermentation profile of the reticulorumen and hindgut, and nutrient digestion in dry cows fed concentrate-rich diets supplemented with a phytogenic feed additive.

This study evaluated the effects of duration of high-concentrate feeding on ruminal and fecal fermentation profile, as well as selected systemic health biomarkers in nonlactating cows supplemented with or without a phytogenic feed additive (PHY). In addition, ruminal degradation kinetics and total-tract nutrient digestibility were evaluated when feeding either only forage or a high-concentrate diet. Nine nonlactating, cannulated Holstein cows were used in a crossover design. Each period included 1 wk of forage feeding (wk 0), diet transition, and 4 wk on the high-concentrate diet (1, 2, 3 and wk 4; 65% dry matter basis). Cows received PHY or not (control). Compared with wk 0, from wk 1 onward, cows on high concentrate showed greater reticular, ruminal, and fecal total volatile fatty acids (VFA), with a greater level of VFA in the rumen than in the hindgut. However, ruminal fermentation was modulated differently by PHY, which showed increased total VFA in wk 1 and increased butyrate in wk 2 in the particle-associated fluid of rumen. In the hindgut, PHY increased propionate in wk 3. Cows fed a high-concentrate diet from wk 1 and onward also showed greater ruminal lactate, as well as lower ruminal and fecal pH, independent of PHY. In addition, compared with cows in wk 1 on a high-concentrate diet, cows in wk 4 had a greater total VFA in free fluid of the rumen and lower fecal pH. Compared with cows at wk 0, cows at wk 1 on high concentrate onward showed greater serum amyloid A and greater activity of glutamate dehydrogenase. In contrast, the high-concentrate diet decreased in situ ruminal degradability of grass silage but increased degradability of corn grain as well as total-tract nutrient digestibility, with total-tract neutral detergent fiber digestibility being greater for cows on the PHY treatment. Overall, from the start of high-concentrate feeding, gut fermentation increased, but differently according to location or PHY, with a stronger build-up of VFA in the rumen compared with the hindgut. In addition, a longer duration on high concentrate exacerbated gut acidification. The enhancing effects of PHY on total VFA and butyrate in particle-associated fluid of the rumen suggest beneficial effects of PHY on particle-associated bacteria, likely contributing to the increased neutral detergent fiber digestibility. The greater production of ruminal butyrate with PHY may be beneficial for the host, given the health benefits of this acid, but more research is needed to elucidate the effects on gut microbiota and the effects of increased butyrate in nonlactating dairy cows.

Immune status and haemato-biochemical profile of buffalo calves supplemented with phytogenic feed additives rich in tannins, saponins and essential oils.

The present study was performed to ascertain the synergistic effects of phytogenic feed additives (PFA-7) supplementation on immune status and haemato-biochemical profile of buffalo calves. The PFA-7 is a mixture of neem seed cake (Azadirachta indica), mahua seed cake (Madhuca longifolia), fennel seed (Foeniculum vulgare), harad (Terminalia chebula), fruit pulp of bahera (Terminalia bellirica), fruit pulp of amla (Phyllanthus emblica) and ajwain seed (Trachyspermum ammi) mixed in 2:2:2:1:1:1:1 proportion. Male buffalo calves (n = 21) having similar age and body weight were allotted to three groups in a completely randomised design. The dietary treatments were viz. T1: control (without PFA-7) and T2 and T3: provided with PFA-7 at 2 and 4% of dry matter intake (DMI), respectively, plus sodium sulphate at 0.06% of DMI. The feeding trial was carried out for 4 months, and serum isolation was done on days 0, 60 and 120 post-feeding. The concentrations of total protein, albumin, globulin, aspartate transaminase and alanine transaminase increased, whereas cortisol and glucose decreased in the supplemented groups as compared to the control. The levels of triglycerides, urea, albumin/globulin ratio, calcium, phosphorus and alkaline phosphatase were not affected by the supplementation of PFA-7. Both cell-mediated and humoral immune response increased in the supplemented groups. The results revealed that PFA-7 positively impacted haemato-biochemical profile and both cellular and humoral immunity of the growing calves. The PFA-7 can be used as an alternative for chemical feed additives in the diet of growing calves.

Effectiveness of Phytogenic Feed Additive as Alternative to Bacitracin Methylene Disalicylate on Hematological Parameters, Intestinal Histomorphology and Microbial Population and Production Performance of Japanese Quails.

This study was conducted to evaluate the effects of phytogenic additive and antibiotic growth promoter in laying Japanese quails. One hundred and sixty five quails were divided into three groups of 5 replicates and 11 quails (8 females and 3 males) in each replicate. Treatment 1 was fed control diet, treatment 2 was fed control diet supplemented with 0.05% bacitracin methylene disalicylate as antibiotic growth promoter and treatment 3 was fed control diet supplemented with 0.1% phytogenic feed additive (PFA) for two periods of 3 weeks each from 37 to 42 weeks of age. Results showed that egg production, eggshell strength, eggshell weight, villus height and villus height to crypt depth ratio were significantly (p≤0.05) increased and feed consumption, feed conversion ratio, albumen, Haugh unit, cholesterol, low-density lipoprotein, alanine transaminase, gamma glutamyltransferase, alkaline phosphatase, high-density lipoprotein, triglyceride, number of goblet cell, crypt depth and intestinal bacterial population of Coliforms, Salmonella and E. coli were significantly (p≤0.05) decreased in PFA fed group. It is concluded that addition of PFA containing phytomolecules and organic acids as main ingredients could significantly improve the production parameters and the general health of laying quails as an alternative to antibiotic growth promoters.

Evaluation of commercial doses of a feed additive and silymarin on broiler performance with and without CCl4-induced liver damage.

Improving productive performance is a daily challenge in the poultry industry. Developing cost-effective additives and strategies that improve performance in antibiotic-free poultry production is critical to maintaining productivity and efficiency. This study evaluates the influence of a commercially available phytogenic feed additive (CA-PFA, that comprises silymarin, betaine and curcumin extracts as main ingredients) and silymarin on commercial broilers' productive performance and liver function with and without carbon tetrachloride (CCl4)-induced liver damage. The experiment was conducted in a completely randomized design, with six treatments, eight replicates, and eight birds per replicate in 18 one-day-old male broilers (Cobb Vantress 500) each; under a 3 × 2 factorial arrangement (3 diets x 2 levels of CCl4, 0 and 1 mL/kg body weight orally). The experimental treatments included 3 diets, commercially recommended doses of CA-PFA (500 mg/kg of feed; this dose provides 70 mg/kg of silymarin, besides the other active ingredients included in the formulation), silymarin (250 mg/kg of feed, containing 28% of active ingredient; this dose provides 70 mg/kg of silymarin as active ingredient) and an additive-free basal diet as a control. A standard commercial silymarin was used as a reference due to its well-known and extensively studied hepatoprotective properties that can mitigate the negative effects of CCl4 in the liver. The data were analyzed as a 2-way ANOVA, and the means showing significant (P ≤ 0.05) differences were then compared using the Post-Hoc Tukey HSD test. No interaction was detected between factors. Exposure to CCl4 had a noticeable detrimental effect on alertness, productive performance, and liver function of broilers without a significant increase in mortality. Including CA-PFA in the diet improved productive performance compared to the basal diet from day 21 to the end of the trial, on day 42. While no influence in feed intake was detected for any treatment, CA-PFA improved body weight gain (BWG) and feed conversion ratio (FCR) significantly (P < 0.05) from day 21 to the end of the trial in healthy and CCl4-exposed birds. The results show that CA-PFA supplementation improves performance parameters in broilers with and without CCl4-induced liver damage, when compared to a basal diet and the addition of a standard commercial silymarin product.

Effects of Artemisia annua supplementation on the performance and gut health of laying hens challenged with mixed Eimeria species.

Background: Coccidiosis outbreaks in susceptible laying hens can significantly decrease egg production and cause substantial economic loss to the egg industry. The supplementation of poultry diets with chemotherapeutic agents is limited due to antimicrobial resistance and residue in poultry meat or processed products. Therefore, alternative strategies to control coccidiosis are needed, and Artemisia annua (AA) might have the potential to be a phytogenic feed additive, an alternative to anticoccidial agents. This study aimed to investigate the effect of the dietary supplementation of powdered AA on the performance and gut health of laying hens infected with coccidiosis by Eimeria spp. Methods: A total of 225 Hy-Line W-36 laying hens at 23 weeks of age were allocated into 5 treatment groups: 1) control (NC), 2) pair-fed (PF) control, 3) challenged control (CC), 4) CC with dietary inclusion of 0.5% AA (0.5AA), and v) CC with dietary inclusion of 1% AA (1AA). The hens in the CC, 0.5AA, and 1AA groups were orally inoculated with sporulated oocysts of Eimeria maxima (12,500), Eimeria tenella (12,500), and Eimeria acervulina (62,500) at week 25. The PF hens received the same amount of feed consumed by the CC hens from 0-14 days post-inoculation (dpi) of Eimeria spp. The performance of the laying hens, including body weight (BW), hen-day egg production (HDEP), feed intake (FI), and feed conversion ratio (FCR), was measured weekly. Additionally, markers of intestinal health, including gut permeability, lesion score, intestinal morphometry, and immune responses, were evaluated at 6, 14, and 21 dpi. Results: At 6 and 14 dpi, laying hens challenged with Eimeria spp. had a lower BW than PF and NC hens (p < 0.0001). Supplementation of 1% AA improved the HDEP by 8.1% compared to CC hens; however, it was still 15.4% lower than that of PF hens (p < 0.0001). The inclusion of 1% AA did not have any beneficial effect on FI; however, the FCR was improved by 0.61 (2.46) than that of CC hens (3.07; p < 0.0001). The inclusion of 1% AA reduced the severity of the intestinal lesions and increased the recovery of intestinal villi (p < 0.05). Additionally, gut permeability was significantly different between the challenged and non-challenged hens; however, among the challenged hens, the inclusion of AA reduced the gut permeability by 29% compared to CC hens (p < 0.0001). Furthermore, the inclusion of 0.5% AA reduced the inflammatory responses in the infected hens. Conclusion: Dietary inclusion of AA partially restored the performance and gut health of the laying hens and modulated their inflammatory immune response following Eimeria infection; however, further studies are needed to better understand the mode of action and effective dosages to improve the gut health without negative impacts on the performance.

Achyranthes japonica extract as phytogenic feed additive enhanced nutrient digestibility and growth performance in broiler.

Achyranthes japonica extract (AJE) is derived from a medicinal plant Achyranthes japonica, known for its anti-inflammatory, antioxidant, and antimicrobial properties. AJE contains multiple bioactive compounds, including saponins, triterpenoids, phytoecdysteroids, 20-hydroxyecdysone, and inokosterone. The aim of this investigation was to examine the impact of AJE as a phytogenic feed additive on growth performance, nutrient digestibility, excreta microbial count, noxious gas emissions, breast meat quality in broilers. About three hundred and sixty, day-old broilers (Ross 308) were assigned into four treatments (five replication cages/treatment, and 18 birds/cage). Dietary treatments: CON, basal diet; 0.02% AJE, basal diet with 0.02%; 0.04% AJE, basal diet with 0.04% AJE, and 0.06% AJE, basal diet with 0.06% of AJE. Body weight gain increased linearly (p < 0.05) through the inclusion of AJE during days 7 to 21, 21 to 35, as well as the entire experimental period. Besides, feed intake increased (p < 0.05) linearly during days 21 to 35 and the entire experiment with the increased AJE doses in broiler diet. Dry matter digestibility was increased (p < 0.05) linearly along with increasing amounts of AJE. With increasing AJE supplementation, nitrogen and energy utilization tended to improve (p < 0.10). In summary, the addition of AJE in the corn-soybean meal diet led to higher body weight gain and increased feed intake as well as enhanced nutrient digestibility, among them the highest improvement was found in 0.06%-AJE indicating the acceptance of AJE as a phytogenic feed additive.

Effect of different ratios of phytogenic feed additives on growth performance, nutrient digestibility, intestinal barrier integrity, and immune response in weaned pigs challenged with a pathogenic Escherichia coli.

This study was conducted to investigate the effects of supplementing different ratios of phytogenic feed additives (PFA) to weaned pigs challenged with pathogenic Escherichia coli on growth performance, nutrient digestibility, intestinal barrier integrity, and immune response, and to determine the optimal mixing ratio for post-weaning diarrhea (PWD) prevention. A total of 48 4-wk-old weaned pigs with initial body weight of 8.01 ± 0.39 kg were placed in individual metabolic cages, and then randomly assigned to eight treatment groups. The eight treatments were as follows: a basal diet without E. coli challenge (negative control, NC), a basal diet with E. coli challenge (positive control, PC), PC with supplementing 0.1% mixture of 20% bitter citrus extract (BCE), 10% microencapsulated blend of thymol and carvacrol (MEO), and 70% excipient (T1), PC with supplementing 0.1% mixture of 10% MEO, 20% premixture of grape seed and grape marc extract, green tea, and hops (PGE), and 60% excipient (T2), PC with supplementing 0.1% mixture of 10% BCE, 10% MEO, 10% PGE, and 70% excipient (T3), PC with supplementing 0.1% mixture of 20% BCE, 20% MEO, and 60% excipient (T4), PC with supplementing 0.1% mixture of 20% MEO, 20% PGE, and 60% excipient (T5), and PC with supplementing 0.1% mixture of 10% BCE, 20% MEO, 10% PGE, and 60% excipient (T6). The experiments progressed in 16 days, including 5 days before and 11 days after the first E. coli challenge (day 0). In the E. coli challenge treatments, all pigs were orally inoculated by dividing a total of 10 mL of E. coli F 18 for three consecutive days from day 0 postinoculation (PI). Compared with the PC group, the PFA2 and PFA6 groups significantly increased (P < 0.05) feed efficiency and decreased (P < 0.05) diarrhea during the entire period. At day 11 PI, the PFA6 group significantly improved (P < 0.05) gross energy digestibility compared to the PFA1 group. The PFA6 group significantly decreased (P < 0.05) tumor necrosis factor α (TNF-α) and interleukin-6 in serum and increased (P < 0.05) the villus height to crypt depth ratio (VH:CD). The PFA2 significantly decreased (P < 0.05) the relative protein expression of calprotectin in the ileum. In conclusion, improvements in growth performance, diarrhea reduction, and immunity enhancement are demonstrated when 10% BCE, 20% MEO, 10% PGE, and 60% excipient are mixed.

Phytogenic feed additives (PFA) include various herbs and spices, such as essential oils and polyphenols. Flavonoids and polyphenols contained in PFA are generally known to have antioxidant and antibacterial actions and based on this, PFA is considered an alternative to antibiotics in the swine industry. Pathogenic Escherichia coli infection is one of the most important causes of post-weaning diarrhea (PWD) in pigs. PWD causes intestinal damage, which leads to severe diarrhea, reduced growth performance, and mortality in weaned pigs, resulting in significant financial loss to the swine industry. Therefore, this study was conducted to investigate the effects of supplementing different ratios of PFA to weaned pigs challenged with E. coli and determine the optimal mixing ratio for PWD prevention. Our study results showed that growth performance was improved when supplementing a mixture of 10% bitter citrus extract (BCE), 20% microencapsulated blend of thymol and carvacrol (MEO), 10% premixture of grape seed and grape marc extract, green tea, and hops (PGE), and 60% excipient. Also, the effect of improving the immune response and intestinal morphology was shown. In conclusion, a mixture of 10% BCE, 20% MEO, 10% PGE, and 60% excipients is considered the optimal mixing ratio.

Effect of papaya (Carica papaya) seed as phytogenic feed additives on egg performance, egg quality and blood serum biochemical constituents of layer hens.

BACKGROUND: Supplementing poultry diets with certain natural phytogenic additives has positive impacts on performance parameters like feed intake, egg production and quality of layer hens. OBJECTIVES: The study aimed to examine how supplementing papaya seed as phytogenic feed additive (PFA) to the diets of layer chickens affected their egg production, quality and blood serum biochemical parameters. METHODS: One hundred twenty 28-week-old Bovans brown laying hens were randomly assigned to one of four treatments with varying levels of papaya seed supplementation at 0 g/kg (T1), 5 g/kg (T2), 10 g/kg (T3) and 15 g/kg (T4) in a complete randomized design. RESULT: Layer chickens supplemented with 0.5% (T2), 1% (T3) and 1.5% (T4) papaya seed as a PFA had significantly (p < 0.05) improved dry matter intake, egg production%, egg mass and feed conversion. On the other hand, papaya seed supplementation decreased (p < 0.05) the bodyweight gain of laying hens. Papaya seed supplementation significantly (p < 0.05) increased egg weight, length, width, yolk height and yolk colour compared to the control group. Serum total protein on T4 and liver enzyme of alkaline phosphatase on T3 were significantly greater (p < 0.05) than in the control group. However, there were no significant differences (p > 0.05) in serum albumin, glucose, total cholesterol, triglyceride and aspartate aminotransferase levels among treatments laying hens. CONCLUSION: Papaya seed can be a potential candidate as a PFA at 5-15 g/kg of the basal diet to improve egg-laying performance and quality without deteriorating effect.

Diet and phytogenic supplementation substantially modulate the salivary proteome in dairy cows.

Phytogenic compounds may influence salivation or salivary properties. However, their effects on the bovine salivary proteome have not been evaluated. We investigated changes in the bovine salivary proteome due to transition from forage to high-concentrate diet, with and without supplementation with a phytogenic feed additive. Eight non-lactating cows were fed forage, then transitioned to a 65% concentrate diet (DM basis) over a week. Cows were control (n = 4, CON) or supplemented with a phytogenic feed additive (n = 4, PHY). Proteomic analysis was conducted using liquid chromatography coupled with mass spectrometry. We identified 1233 proteins; 878 were bovine proteins, 189 corresponded to bacteria, and 166 were plant proteins. Between forage and high-concentrate, 139 proteins were differentially abundant (P < 0.05), with 48 proteins having a log2FC difference > |2|. The salivary proteome reflected shifts in processes involving nutrient utilization, body tissue accretion, and immune response. Between PHY and CON, 195 proteins were differently abundant (P < 0.05), with 37 having a log2FC difference > |2|; 86 proteins were increased by PHY, including proteins involved in smell recognition. Many differentially abundant proteins correlated (r > |0.70|) with salivary bicarbonate, total mucins or pH. Results provide novel insights into the bovine salivary proteome using a non-invasive approach, and the association of specific proteins with major salivary properties influencing rumen homeostasis. SIGNIFICANCE: Phytogenic compounds may stimulate salivation due to their olfactory properties, but their effects on the salivary proteome have not been investigated. We investigated the effect of high-concentrate diets and supplementation with a phytogenic additive on the salivary proteome of cows. We show that analysis of cows' saliva can be a non-invasive approach to detect effects occurring not only in the gut, but also systemically including indications for gut health and immune response. Thus, results provide unique insights into the bovine salivary proteome, and will have a crucial contribution to further understand animal response in terms of nutrient utilization and immune activity due to the change from forage to a high-energy diet. Additionally, our findings reveal changes due to supplementation with a phytogenic feed additive with regard to health and olfactory stimulation. Furthermore, findings suggest an association between salivary proteins and other components like bicarbonate content.

Effect of Duration of High-Grain Feeding on Chewing, Feeding Behavior, and Salivary Composition in Cows with or without a Phytogenic Feed Supplement.

Switching diets from forage to a high-grain (HG) diet increases the risk of rumen fermentation disorders in cattle. However, the effects of the duration of the HG feeding, after the diet switch, on animal behavior and health have received considerably less attention. This experiment primarily aimed to assess the effects of the duration of an HG diet on the chewing, eating, and lying behavior and salivation dynamics in a control group (CON) and a group of cows receiving a phytogenic feed supplement (TRT) at 0.04% (DM basis), which included L-menthol, thymol, eugenol, mint oil, and cloves powder. The experiment was a crossover design with nine non-lactating cows, and two experimental periods with an intermediate washout of four weeks. In each period, the cows were first fed a forage diet for a week to collect baseline measurements representing week 0; then, the diet was switched over a week to HG (65% concentrate), which was fed for four continuous weeks (week 1, week 2, week 3, and week 4 on an HG diet, respectively). The cows were divided in two groups of four and five animals and were randomly allocated to CON or TRT. The data analysis revealed that at the start of the HG feeding, the dry matter intake and the cows' number of lying bouts increased, but the eating time, rumination time, and meal frequency decreased, resulting in a greater eating rate. We also found that an advanced duration on an HG diet further decreased the rumination time, total chewing time, chewing index, and sorting in favor of short feed particles, with the lowest values in week 4. The feed bolus size increased but feed the ensalivation decreased in week 4 compared to week 0. The dietary switch increased salivary lysozyme activity, and the advanced duration on the HG diet increased salivary pH, but salivary phosphate decreased in weeks 1 and 2 on the HG diet. Supplementation with TRT increased sorting in favor of physically effective NDF (peNDF) in week 2 and increased salivary pH in week 4 on an HG diet. Overall, the negative effects of the HG diet in cattle are more pronounced during the initial stage of the HG feeding. However, several detrimental effects were exacerbated with the cows' advanced duration on feed, with host adaptive changes still observed after 3 and 4 weeks following the diet switch. The TRT mitigated some of the negative effects through the temporal improvement of the salivary properties and the intake of peNDF, which are known to modulate rumen fermentation.

Effects of a Phytogenic Supplement Containing Olive By-Product and Green Tea Extracts on Growth Performance, Lipid Metabolism, and Hepatic Antioxidant Capacity in Largemouth Bass (Micropterus salmoides) Fed a High Soybean Meal Diet.

A 10-week growth trial was conducted to investigate the effects of a phytogenic feed additive (PFA) containing olive by-products and green tea extracts supplemented to a reduced fishmeal/high soybean meal diet on the growth performance, hepatic antioxidant capacity, lipid metabolism, and liver health of largemouth bass (Micropterus salmoides). Three experimental diets were tested: (1) a control high fishmeal (40%) and low soybean meal (15.57%) diet (named HFM), (2) a reduced fishmeal (30%) and high soybean meal (30.97%) diet (named HSB), and (3) a HSB diet supplemented with the PFA at 500 mg/kg (named HSB+P). Each diet was assigned to four replicate tanks, each containing 30 largemouth bass (initial body weight, IBW = 48.33 ± 0.01 g). The results showed that increasing the soybean meal content in the diet did not negatively affect growth performance, whereas supplementation with PFA significantly increased weight gain and specific growth rate of largemouth bass compared to both HFM and HSB groups. Reducing fishmeal and increasing soybean meal in the diet caused oxidative stress with a higher content of ROS in the liver. However, the hepatic antioxidant capacity was enhanced, with reduced ROS and increased GSH-Px levels in the HSB+P group. Moreover, the decrease of plasma TG, LDL-C, and LDL-C/TC, and downregulation of lipogenesis and cholesterol synthesis gene expression in liver, indicated that supplementation with the PFA improved fish lipid metabolism. Protein retention efficiency was also significantly increased in largemouth bass fed the diet with PFA supplementation, which regulated (enhanced) AKT-mTOR phosphorylation. These results clearly indicated that a PFA containing olive by-product and green tea extracts can positively improve growth performance, protein retention efficiency, antioxidant capacity, and lipid metabolism of largemouth bass fed a reduced fishmeal/high soybean meal diet.

Evaluating Ruminal and Small Intestinal Morphology and Microbiota Composition of Calves Fed a Macleaya cordata Extract Preparation.

The objective was to determine the impact of feeding MCE on ruminal and intestinal morphology and microbiota composition of calves. A total of 10 male and 10 female crossbred (dairy × beef) calves (6 d of age) were assigned randomly to control (CTL; n = 10) or MCE-supplemented (TRT; n = 10) groups. The MCE was fed in the milk replacer and top-dressed on the calf starter during pre-weaning (6 to 49 d) and post-weaning (50 to 95 d) periods, respectively. Calves were slaughtered at 95 d to collect rumen and intestinal samples to determine volatile fatty acid (VFA) profile, mucosal morphology, and microbiota composition. The effects of MCE were analyzed by accounting for the sex and breed effects. Feeding MCE increased rumen papillae length (p = 0.010) and intestinal villus height: crypt depth (p < 0.030) compared to CTL but did not affect rumen VFA profile. The TRT had a negligible impact on microbial community composition in both the rumen and the jejunum. In conclusion, feeding MCE from birth through weaning can improve ruminal and small intestinal mucosa development of calves despite the negligible microbiota composition changes observed post-weaning.

Evaluation of Non-Fermented and Fermented Chinese Chive Juice as an Alternative to Antibiotic Growth Promoters of Broilers.

The present study explores the application of CC juice as a suitable feed additive and alternative to conventional antibiotics. We performed a comparative study to investigate the effects of non-fermented and fermented CC juice on broiler productivity, meat quality, blood characteristics, intestinal characteristics, and microbiota associated with intestinal characteristics. A total of 800 one-day-old Ross 308 broiler chickens were randomly assigned to one of the four dietary treatment groups: (1) basal diet (negative control; NC); (2) basal diet + 0.01% enramycin (positive control; PC); (3) basal diet + 3% non-fermented CC juice (NCC; CC juice 10%, water 90%); and (4) basal diet + 3% fermented CC juice (FCC; CC juice 10%, water 90%, Lactobacillus plantarum SK4719). Feed and water were provided ad libitum. Intriguingly, all treatments showed similar results in terms of broiler productivity and chicken meat quality. Considering organ characteristics, the FCC group showed a low spleen weight and lower (p < 0.05) blood levels of AST and total cholesterol (TCHO). Regarding intestinal characteristics, the CC feed additive (NCC and FCC) resulted in a heavier intestinal weight (p < 0.05) without affecting the length ratio of the villi or the crypt compared to the control (NC or PC). NCC and FCC lowered the growth of intestinal pathogens (p < 0.01). In summary, the addition of FCC can maintain poultry health by improving blood compositions and inhibiting the growth of intestinal pathogens, leading to a productivity comparable to that of poultry treated with growth-promoting antibiotics.

Phytogenic feed additives alleviate pathogenic Escherichia coli-induced intestinal damage through improving barrier integrity and inhibiting inflammation in weaned pigs.

BACKGROUND: This study was conducted to investigate the effects of each phytogenic feed additive (PFA; PFA1, bitter citrus extract; PFA2, a microencapsulated blend of thymol and carvacrol; PFA3, a mixture of bitter citrus extract, thymol, and carvacrol; PFA4, a premixture of grape seed, grape marc extract, green tea, and hops; PFA5, fenugreek seed powder) on the growth performance, nutrient digestibility, intestinal morphology, and immune response in weaned pigs infected with Escherichia coli (E. coli). RESULTS: A total of 63 4-week-old weaned pigs were placed in individual metabolic cages and assigned to seven treatment groups. The seven treatments were as follows: 1) NC; basal diet without E. coli challenge, 2) PC; basal diet with E. coli challenge, 3) T1; PC + 0.04% PFA1, 4) T2; PC + 0.01% PFA2, 5) T3; PC + 0.10% PFA3, 6) T4; PC + 0.04% PFA4, 7) T5; PC + 0.10% PFA5. The experiments lasted in 21 d, including 7 d before and 14 d after the first E. coli challenge. In the E. coli challenge treatments, all pigs were orally inoculated by dividing a total of 10 mL of E. coli F18 for 3 consecutive days. The PFA-added groups significantly increased (P < 0.05) average daily gain and feed efficiency and decreased (P < 0.05) the fecal score at d 0 to 14 post-inoculation (PI). Tumor necrosis factor α was significantly lower (P < 0.05) in the PFA-added groups except for T1 in d 14 PI compared to the PC treatment. The T3 had a higher (P < 0.05) immunoglobulin G and immunoglobulin A concentration compared to the PC treatment at d 7 PI. Also, T3 showed significantly higher (P < 0.05) villus height:crypt depth and claudin 1 expression in ileal mucosa, and significantly down-regulated (P < 0.05) the expression of calprotectin compared to the PC treatment. CONCLUSIONS: Supplementation of PFA in weaned pigs challenged with E. coli alleviated the negative effects of E. coli and improved growth performance. Among them, the mixed additive of bitter citrus extract, thymol, and carvacrol showed the most effective results, improving immune response, intestinal morphology, and expression of tight junctions.

Protective effects of the phytogenic feed additive "comfort" on growth performance via modulation of hypothalamic feeding- and drinking-related neuropeptides in cyclic heat-stressed broilers.

Identification of alternatives to antibiotics in livestock and poultry is necessary. Fueled by consumer preferences, phytogenic feed additives are increasingly used in the food system; however, their mode of action is not well defined. Here, we used broiler chickens, in which appetite and feeding behavior regulation are controlled by complex mechanisms, to determine the effect of the phytogenic feed additive "comfort" (PFA-C) as well as its underlying molecular mechanisms on growth performance in heat-stressed broiler chickens. Heat stress significantly increased birds' core body temperature, water intake, and the hypothalamic expression of heat shock protein (HSP) 70, whereas it decreased feed intake, BW, and woody breast incidence. Phytogenic feed additive "comfort" supplementation downregulated the hypothalamic expression of HSP70, reduced core body temperature, increased feed and water intake, and improved BW in HS broilers. At molecular levels, the effect of PFA-C on growth performance seemed to be mediated by modulation of hypothalamic expression of melanocortin receptor 2, arginine vasopressin, aquaporin 2, and sodium and potassium-transporting ATPase subunit beta 1 polypeptides. In summary, PFA-C supplementation ameliorates heat stress productivity losses via a potential cytoprotective effect, reduction of hypothalamic intracellular stress, and modulation of hypothalamic feeding- and drinking-related polypeptide expression.

Effect of a Phytogenic Feed Additive on Growth Performance, Nutrient Digestion, and Immune Response in Broiler-Fed Diets with Two Different Levels of Crude Protein.

The aim of this experiment was to evaluate the effect of a phytogenic feed additive (PFA) on growth performance and nutrient digestibility of broilers fed corn and soybean meal-based diets containing two different levels of crude protein. A 2 × 2 completely randomized factorial arrangement (eight replicates/treatment, 30 birds/replicate) was conducted with a positive control (PC) and negative control (NC) containing crude protein at standard or reduced by 1.5% (equivalent to a reduction of 15 g/kg), respectively, and supplementation of PFA at 0 or 125 ppm of diet. There were no significant interactions found between PFA and CP levels in the current study. Main effect analysis showed that during 0-42 d of age NC diets decreased body weight gain (p < 0.05), but increased feed intake (p < 0.05) and feed conversion ratio (FCR, p < 0.01), whereas supplementation of PFA resulted in a lower FCR (p < 0.01). The ileal nutrient digestibility was reduced (p < 0.05) in the broilers fed a reduced protein diet at 21 d compared to the standard protein level group, but there were no effects for PFA levels. Similarly, supplementing PFAs showed no effects on digestive enzyme (Alkaline phosphatase, amylase, and lipase) activity in jejunal digesta and jejunal brush border enzyme (maltase, sucrase, and aminopeptidase) activity. Supplementation of PFA downregulated (p < 0.05) the mRNA expressions of cytochrome P450 1A and interleukin 6 in the ileum but had no effects on nutrient transporter genes in the jejunum. In conclusion, supplementation of PFA reduced broiler FCR during the whole grow-out period and positively regulated the immune responses in the ileum.