Effects of Dietary Inclusion of Probiotic or Prebiotic on Growth Performance, Organ Weight, Blood Parameters and Antibody Titers Against Influenza and Newcastle in Broiler Chickens

Oral supplementation with postbiotics modulates the immune response produced by myxomatosis vaccination in wild rabbits

Rabbits (Oryctolagus cuniculus) are vitally important species in the Iberian Peninsula ecosystem. However, since 1950, there has been a significant population decline, with major repercussions. This situation is mainly due to the presence of infectious diseases, such as myxomatosis, which is expanding and is characterized by severe and fatal clinical manifestations. Current control measures, mainly those based on vaccinations, are ineffective. Therefore, new strategies need to be developed and implemented. This study aimed to evaluate whether supplementation with postbiotic products modulates the immune response in wild rabbits vaccinated against myxomatosis. For this purpose, two groups of rabbits were established: a control group fed with standard feed ad libitum from weaning (28 days) until two months of age, and a treated group, which was fed under the same conditions but supplemented with postbiotics (3 kg/Tm). All the studied rabbits were vaccinated against this disease during weaning. In addition, a blood samples were obtained from all animals immediately before vaccination and 30 days later, which allowed us to evaluate the level of antibodies against myxomatosis virus (ELISA detection) and the relative expression of gene encoding to cytokines related to the immune response (IL6, TNFα and IFNγ), at both times of the experience. Weight and length measurements were also taken at both times to calculate body index and mean daily gain (MDG). No statistically significant differences in growth parameters were observed. There were also no differences in the serological response among groups. However, a relative underexpression of gene codifying to TNFα (p-value = 0.03683) and a higher expression on IFNγ (p-value = 0.045) were observed in the treated group. This modulation in cytokines could lead to less severe lesions in wild rabbit naturally infected with myxomatosis virus.

Influence of dietary mannan-oligosaccharides supplementation on hematological characteristics, blood biochemical parameters, immune response and histological state of laying hens

This study aimed to determine the influence of dietary mannan-oligosaccharides (MOS) on the immune system, hematological traits, blood biochemical parameters, and histological state of laying hens. At 34 wk of age, The Mandarah chicken strain's 120 laying hens and 12 cocks were divided into 4 groups, each with 30 hens and 3 cocks. The first group performed as a control group, which nourished on a basal diet. The second, third, and fourth experimental groups received 0.1, 0.2, and 0.5 g/kg of MOS and a base diet, respectively. Birds obtained MOS at numerous doses significantly (P ˂ 0.05) raised serum levels of immunoglobulin Y (IgY), immunoglobulin M (IgM), and avian influenza (AI) antibodies compared to control birds. Furthermore, adding MOS at a level of 0.1 g/kg diet significantly improved the immune response of the control group. Additionally, compared to the control group, treated birds with MOS at various dosages did not significantly enhance hematological parameters such as red blood cells (RBCs), white blood cells (WBCs), hemoglobin, and hematocrit. Compared to control birds, birds fed MOS at all levels exhibited considerably lower serum cholesterol, alanine aminotransferase (ALT), and aspartate aminotransferase (AST) values. Also, compared to other treated birds, MOS-treated birds displayed improved histological examination of the small intestine, isthmus, and testis compared to the control group, particularly in birds fed MOS at 0.1 and 0.2 g/kg diet. It could be concluded that using MOS at 0.1 or 2 g/kg diet can successfully improve the physiological performance and overall health of laying hens.

Effects of mannan-oligosaccharide supplementation on gut health, immunity, and production performance of broilers

The study was designed to investigate the effect of mannan-oligosaccharide (MOS) supplementation on intestinal histomorphology, immunity against Newcastle disease virus (NDV) and productive parameters of broilers. A total of 1800, day old broiler chicks of Cobb-500 strain were selected and randomly assorted into 6 treatment groups: T1 (basal diet without antibiotics as negative control); T2 (basal diet plus antibiotics as positive control group); T3 (basal diet plus 200g/ton MOS); T4 (basal diet plus 400g/ton MOS); T5 (basal diet plus 600g/ton MOS) and T6 (basal diet plus 800g/ton MOS). Each treatment was having 6 replicates and the feed intake, body weight gain and feed conversion ratio (FCR) were recorded on weekly basis. Results showed that, MOS supplemented birds have significantly higher feed intake, weight gain and FCR (P < 0.05). Similarly, supplementation of MOS showed positive effect on villus height and crypt depth both in jejunum and ilium. Goblet cell density was unaffected by MOS addition (P < 0.05). Furthermore, birds fed with diets containing MOS, exhibited better productive performance in comparison to positive and negative control groups. In conclusion, MOS can replace antibiotic growth promoters (AGPs) as non-microbial performance-enhancing feed advocates.

Effect of a synbiotic supplement as an antibiotic alternative on broiler skeletal, physiological, and oxidative parameters under heat stress

The aim of this study was to examine if synbiotics can function as alternatives to antibiotics in broiler production under heat stress (HS). Day-old broiler chicks (528 birds) were randomly placed in floor pens within 2 identical temperature-controlled rooms (11 birds/pen and 24 pens/room). The pens of each room were evenly divided among 3 treatments (n = 8): basal diet (CON), the basal diet mixed with 50 ppm of bacitracin methylene disalicylate (BMD) or a synbiotic (50 ppm of PoultryStar me^US, SYN). From d 15, room 2 was under thermoneutral (TN) conditions (TN-CON, TN-BMD, and TN-SYN), while HS was applied to room 1 at 32^oC for 9 hrs/d (0800 to 1700) (HS-CON, HS-BMD, and HS-SYN). Treatment effects on footpad dermatitis and gait score were measured on 5 birds/pen, and latency to lie (LTL) test was measured on 2 birds/pen at d 27 and d 41; and 1 broiler/pen was sampled on d 28 and d 42, respectively. Body, liver, and spleen weight were determined. Plasma levels of interleukins (IL), heat shock protein 70, immunoglobulin (Ig)Y, liver superoxide dismutase (SOD) and glutathione peroxidase (GPx) enzyme activities were examined. Heat stress suppressed BW and IgY concentrations on both d 28 and d 42, while suppressed plasma IL-6 concentrations, SOD activities, and LTL duration on d 28 only (P < 0.05). Among all treatments, SYN birds had the best foot and skeletal health scores on both d 27 and d 41 (P < 0.05). On d 42, SYN increased BW, and TN-SYN birds had higher relative spleen weight than both TN-BMD and TN-CON birds (P < 0.05). Antibiotic BMD increased BW (P < 0.05) but decreased SOD activities (P < 0.05) on d 42. These results indicate that the SYN supplementation decreases HS negative effect on broilers by improving BW, foot, and skeletal health, while BMD improves BW but also increases oxidative stress in broilers. The data suggest that synbiotic supplement may function as an alternative to antibiotics in broiler production during summer seasons, especially in the tropical and subtropical regions.

Effects of Lactobacillus reuteri and Streptomyces coelicolor on Growth Performance of Broiler Chickens

There are well documented complications associated with the continuous use of antibiotics in the poultry industry. Over the past few decades, probiotics have emerged as viable alternatives to antibiotics; however, most of these candidate probiotic microorganisms have not been fully evaluated for their effectiveness as potential probiotics for poultry. Recent evaluation of a metagenome of broiler chickens in our laboratory revealed a prevalence of Lactobacillus reuteri (L. reuteri) and Actinobacteria class of bacteria in their gastrointestinal tract. In this study Lactobacillus reuteri and Streptomyces coelicolor (S. coelicolor) were selected as probiotic bacteria, encapsulated, and added into broiler feed at a concentration of 100 mg/kg of feed. In an 8-week study, 240 one day-old chicks were randomly assigned to four dietary treatments. Three dietary treatments contained two probiotic bacteria in three different proportions (L. reuteri and S. coelicolor individually at 100 ppm, and mixture of L. reuteri and S. coelicolor at 50 ppm each). The fourth treatment had no probiotic bacteria and it functioned as the control diet. L. reuteri and S. coelicolor were added to the feed by using wheat middlings as a carrier at a concentration of 100 ppm (100 mg/kg). Chickens fed diets containing L. reuteri and S. coelicolor mixture showed 2% improvement in body weight gain, 7% decrease in feed consumption, and 6–7% decrease in feed conversion ratios. This research suggests that L. reuteri and S. coelicolor have the potential to constitute probiotics in chickens combined or separately, depending on the desired selection of performance index.

Benefit of Dietary Supplementation with Bacillus subtilis BYS2 on Growth Performance, Immune Response, and Disease Resistance of Broilers

A strain of Bacillus subtilis (B. subtilis) BYS2 was previously isolated from Mount Tai, which is located in Tai'an City in the Shandong Province of China. The strain was then stored in the Environmental Microbiology Laboratory at Shandong Agricultural University. To evaluate the effect of the bacterium preparation in broiler production, we fed the bacterium (10⁶ CFU/g) to 1-day-old broilers and continued this feeding for 6 weeks to analyze its effect on growth and immune performance. We found that the average weight of the bacterium-fed group increased by 17.19% at weeks 5 compared to the control group (P < 0.05). The height of the villi in the duodenum and jejunum and the ratio of villi to crypt were significantly increased in the bacterium-fed group at weeks 5 (P < 0.05). Also, the IgG in the serum of broilers in the experimental group increased by 31.60% (P < 0.05) and IgM 30.52% (P < 0.05) compared with those in the control group. The expressions of the major pattern recognition receptors (PRRs), antiviral proteins, pro-inflammatory cytokines, and β-defensins were significantly higher than those in the control group (P < 0.05). Meanwhile, the bursa immune organ indices of broilers in the experimental group were significantly higher than those in the control group (P < 0.05). Also, after 5 weeks of continuous feeding, when infected with Escherichia coli (E. coli) O1K1 and Newcastle disease virus (NDV) F48E8, the content of bacteria and virus in tissues and organs of the experimental group decreased significantly, and the survival rate of infected chickens increased by 31.1% and 17.7%, respectively (P < 0.05). These results show that the anti-infective B. subtilis BYS2 could, to some extent, replace antibiotics to promote growth, improve innate immunity, and enhance disease resistance in broilers.

Dietary effect of probiotics and prebiotics on broiler performance, carcass, and immunity

This experiment was carried out to evaluate the effects of dietary addition of probiotics (Protexin) and prebiotics (active MOS, mannan oligosaccharides) on growth performance, carcasses, and antibody titer in broilers. A total number of 360-day-old Ross broiler chicks were randomly divided into 9 groups in a 3 × 3 factorial arrangement. Nine broiler starter (0-21 d) and finisher (21-35 d) diets were formulated by using 3 levels of probiotics (0, 1, and 2 g/kg of feed) and 3 levels of MOS (0, 1, and 1.5 g/kg of feed) and were randomly allotted to 9 groups. Feed intake was not affected by interaction of treatments during all phases (P > 0.05). Feed intake was improved due to the main effect of probiotic (P = 0.0001) or MOS (P = 0.005). No interaction (P > 0.05) was observed for weight gain in the starter, finisher, and overall phases. While, during the starter and finisher phases, weight gain was increased by probiotics (P = 0.028 or 0.04, respectively). Dietary supplementation of MOS improved weight gain (P = 0.01) and feed conversion ratio (FCR) (P = 0.03) during the overall period, but during starter and finisher periods, weight gain and FCR were not affected by prebiotics. Apart from dressing percentage, no interaction or individual effect of probiotics and prebiotics was observed for carcass, breast, thigh, heart, liver, and gizzard weight. Antibody titer for infectious bursal disease (IBD) was improved (P = 0.026) by the interaction effect between probiotics and prebiotics, when compared with the control group. Antibody titer against Newcastle disease (ND) was not affected by probiotics or prebiotics or their interactions (P > 0.05). It could be concluded that supplementation of prebiotics or probiotics can improve the growth performance of broilers. It may also be helpful in improving the antibody titer against IBD in broilers fed antibiotic-free diets.

Dietary curcumin supplementation effects on blood immunological profile and liver enzymatic activity of laying hens after exposure to high temperature conditions

Various environmental factors affect livestock production but heat stress is a major challenge in the poultry farming. Poultry exposes to high temperature alters blood immunological parameters and liver enzymatic function which in turn, suppress the immunity and disease resistance of chickens. Thus, the purpose of present study was to explore the effect of dietary curcumin supplementation on blood immunological biomarker and liver enzymatic activity of laying hens under heat stress conditions. Experimental groups contained two control groups (normal temperature control (NC) and heat stress control (HC) and 3 heat stress curcumin treatment groups (HT100, HT200 and HT300). Hens in HC group with basal diet and heat stress curcumin treatment groups were exposed 6 h/day heat stress (32 ± 1 °C) from 10:00 a.m. to 16:00 p.m. for 9 week. The results of present study showed that heat stressed curcumin treatment group had improved liver weight, WBC values and immunoglobulin level as compared to untreated HC and NC groups. The available results also indicated that laying hens supplemented with curcumin under high temperature conditions had reduced H/L ratio, serum corticosterone levels, inflammatory cytokines response and liver enzymatic activity (ALT) which enhanced the immunity of laying hens under hot climatic conditions. Therefore, it is concluded that curcumin has ability to combat harsh environmental conditions which can be used as anti-inflammatory and immune booster feed additive in the poultry nutrition.

Effect of dietary supplementation of prebiotic on growth performance, immune response and intestinal microbial load in broiler chickens

The experiment was conducted to study the effect of using prebiotic (mannan oligosachharide -MOS) in place of antibiotic growth promoter (AGP) on performance, immune response and intestinal microbial load in broiler chickens. Day-old broiler chicks (192) were randomly distributed into 20 groups each of 8 chicks (4 treatments × 6 replicates). Four experimental diets T1, T2, T3 and T4 were formulated to contain no additive, bacitracin methylene di-salicylate (BMD) at 20 mg/kg diet, MOS at 0.1 and 0.2%, respectively. Body weight gain (g) was increased by the feeding of diets containing 0.2% levels of MOS, but feed intake (g), feed conversion ratio (FCR) and mortality (%) did not differ significantly. Antibody (28 d), titres were significantly higher after feeding 0.1 or 0.2% MOS and antibiotic (T2) supplemented group. During d 35, the response to intra-dermally injected phyto-hemagglutinin, an index of the in vivo cell-mediated immune response, was increased in the 0.2% MOS supplemented group. Significant reduction was observed in coliforms and total plate count in cecal (28 and 42 d) and excreta (42 d) in MOS (0.1 or 0.2%) or antibiotic (T2) supplemented groups. Lactobacillus count significantly increased in cecal (28 and 42 d) and excreta (42 d) in MOS @0.1 or 0.2% supplemented groups. Thus, it can be concluded that, 0.2% MOS with basal diet has a beneficial effect for growth performance, immune response and gut health status in broiler chickens, and MOS could be a good alternative to antibiotic growth promoter.

Dietary supplementation of Aspergillus oryzae meal and its effect on performance, carcass characteristics, blood variables, and immunity of broiler chickens

This study investigated the effect of different levels and consumption periods of Aspergillus oryzae meal on performance, carcass characteristics, blood variables, and immunity of broiler chickens. A total of 270 (male and female) Ross 308 chicks were randomly assigned to 9 treatment groups. Two levels (2 g/kg diet and 4 g/kg diet as-fed) of Aspergillus oryzae meal (AO) and 4 consumption periods of AO (starter, grower, finisher, and entire period) in a 2 × 4 factorial arrangement were used. Compared with control, AO used during the entire rearing period increased weight gain, reduced relative weight of abdominal fat, aspartate aminotransferase (AST), and alanine aminotransferase (ALT) serum levels, and increased antibody titers against influenza and Newcastle disease vaccination and sheep red blood cells injection. Few differences in the variables considered were found if AO was added to broiler diets only during specific consumption periods, and between the two supplementation levels of AO. In conclusion, the addition of AO to the broiler diet can have beneficial effects in terms of performance, carcass composition, and health, but these positive effects were mainly reached adding AO for the entire rearing period.

Production performance, immune response and blood biochemical parameters in broiler chickens fed diet incorporated with prebiotics

This experiment was conducted to identify the suitable replacer of broiler feed antibiotics with prebiotics (mannan oligosaccharides-MOS or fructooligosaccharide-FOS). Two hundred and forty (240)-day-old chicks were randomly divided into 30 groups (6 treatments x 5 replicates/treatment x 8 chicks/replicate). Six experimental diets T₁ , T₂ , T₃ , T₄ , T₅ and T₆ were formulated to contain an additional 0, antibiotic, that is, bacitracin methylene di-salicylate (BMD) @20 mg/kg, MOS (0.1% and 0.2%) and FOS (0.1% and 0.2%) respectively. Body weight gain was significantly (p < 0.05) increased in MOS-0.2% supplemented group at 0-21 d and 0-42 d of broiler chicken. Humoral and in vivo cell-mediated immune response were significantly improved (p < 0.05) in BMD, MOS @0.1% or 0.2% treated group. Significant (p < 0.05) increase was recorded in total protein (except 21 d), albumin and aspartate amino transferase (AST) and decrease (p < 0.05) in alanine amino transferase (except 42 d), cholesterol and uric acid concentration. The weight of breast, thigh, back, drumstick bursa of Fabricius and thymus were higher (p < 0.05) in the birds given the MOS @0.2% (T₄ ). It is concluded that MOS @0.2% may be suitable replacer of antibiotic growth promoter, and it has a beneficial effect on production performance, immune responses, blood biochemical parameters and cut up parts in broiler chickens.

Influence of different prebiotics and mode of their administration on broiler chicken performance

In the post-antibiotics era, prebiotics are proposed as alternatives to antibiotic growth promoters in poultry production. The goal of this study was to compare in ovo method of prebiotic delivery with in-water supplementation and with both methods combined (in ovo+in-water) in broiler chickens. Two trials were conducted. Trial 1 was carried out to optimize the doses of two prebiotics, DN (DiNovo®, extract of beta-glucans) and BI (Bi2tos, trans-galactooligosaccharides), for in ovo delivery. The estimated parameters were hatchability and bacteriological status of the newly hatched chicks. Prebiotics were dissolved in 0.2 ml of physiological saline, at the doses: 0.18, 0.88, 3.5 and 7.0 mg/embryo; control group (C) was injected in ovo with 0.2 ml of physiological saline. Trial 2 was conducted to evaluate effects of different prebiotics (DN, BI and raffinose family oligosaccharides (RFO)) delivered in ovo, in-water and in a combined way (in ovo+in-water) on broiler chickens performance. The results of the Trial 1 indicated that the optimal dose of DN and BI prebiotics delivered in ovo, that did not reduce chicks' hatchability, was 0.88 mg/embryo (DN) and 3.5 mg/embryo (BI). Both prebiotics numerically increased number of lactobacilli and bifidobacteria in chicken feces (P>0.05). In Trial 2, all prebiotics (DN, BI and RFO) significantly increased BW gain compared with the C group (P<0.05), especially during the first 21 days of life. However, feed intake and feed conversion ratio were increased upon prebiotics delivery irrespective of method used. Injection of prebiotics in ovo combined with in-water supplementation did not express synergistic effects on broilers performance compared with in ovo injection only. Taken together, those results confirm that single in ovo prebiotics injection into the chicken embryo can successfully replace prolonged in-water supplementation post hatching.