Objective: This study was conducted to investigate the effects of dietary multi-strain probiotic (MSP) (Bacillus coagulans Unique IS2 + Bacillus subtillis UBBS14 + Saccharomyces boulardii Unique 28) on performance, gut morphology and expression of nutrient transporter related genes in broiler chickens.Methods: A total of 256 (4×8×8) day-old CARIBRO Vishal commercial broiler chicks of uniform body weight were randomly distributed into four treatments with 8 replicates each and having eight chicks in each replicate. Four dietary treatments were T1 (negative control-basal diet), T2 (positive control-antibiotic bacitracin methylene disalicylate at 20 mg/kg diet), T3 (MSP at 107 colony-forming unit [CFU]/g feed), and T4 (MSP at 108 CFU/g feed).Results: During 3 to 6 weeks and 0 to 6 weeks, the body weight gain increased significantly (p<0.05) in T3 and T4 groups. The feed intake significantly (p<0.05) reduced from T1 to T3 during 0 to 3 weeks and the feed conversion ratio also significantly (p<0.05) improved in T3 and T4 during 0 to 6 weeks. The humoral and cell mediated immune response and the weight of immune organs were also significantly (p<0.05) improved in T3 and T4. However, significant (p<0.05) dietary effects were observed on intestinal histo-morphometry of ileum in T3 followed by T4 and T2. At 14 d post hatch, the relative gene expression of glucose transporter (GLUT5), sodium-dependent glucose transporter (SGLT1) and peptide transporter (PepT1) showed a significant (p<0.05) up-regulating pattern in T2, T3, and T4. Whereas, at 21 d post hatch, the gene expression of SGLT1 and PepT1 was significantly (p<0.05) downregulated in MSP supplemented treatments T3 and T4.Conclusion: The supplementation of MSP at 107 CFU/g diet showed significant effects with improved performance, immune response, gut morphology and expression of nutrient transporter genes. Thus, the MSP could be a suitable alternative to antibiotic growth promoters in chicken diets.

This study investigated the role of synbiotic supplementation on gut histomorphology, expression of nutrient transporters, and nutrient utilization in broiler chicken. Bacitracin methylene disalicylate (BMD), Probiotic Lactobacillus acidophilus (LBA), and prebiotic Mannan-oligosaccharides (MOS) were used to formulate total 6 dietary treatments viz. T1 (control; basal diet), T2 (BMD @ 20 mg/kg diet), T3/T4 (0.1% MOS with 106 and 107 cfu LBA/g diet), and T5/T6 (0.2% MOS with 106 and 107 cfu LBA/g diet). A total of 288 day old chicken were allocated at random among six treatments, each with six replicates of eight chicken (48 birds/treatment). Results revealed higher villus height, crypt depth, villus height: crypt depth ratio, and histological surface magnification ratio values in chicken fed a combination of MOS (0.2%) and LBA (106 or 107 cfu/g diet). BMD supplemented birds had higher values of these parameters compared to control birds. The villus width, villus bottom area, and mucosal unit bottom area were all increased in birds supplemented with BMD, but were similar to birds fed a combination of MOS (0.1 percent) and LBA (107 cfu/g diet). The villus width, villus bottom area, and mucosal unit bottom area were higher in BMD supplemented birds which were similar to the birds fed a combination of MOS (0.1%) and LBA (107 cfu/g diet). The birds fed a combination of MOS (0.2%) and LBA (106 or 107 cfu/g diet) revealed upregulation of SGLT1 and GLUT5 expression in jejunum but no significant effect was observed on the expression of PePT1 and EAAT3 gene. The AME Diet, nitrogen, phosphorus, and calcium retentions were higher in birds fed a combination of MOS (0.2%) and LBA (106 or 107 cfu/g diet). However, the organic matter digestibility was higher in birds fed a combination of MOS (0.2%) and LBA (106 cfu/g diet) and BMD supplementation also improved the organic matter utilization compared to control. In conclusion, the supplementation of a combination of MOS (0.2%) and LBA (106 or 107 cfu/g diet) improves the intestinal architecture along with upregulation of SGLT1 and GLUT5 nutrient transporters and increase in nutrient digestibility in broiler chicken.

The objective of this study was to investigate the effects of feeding rice gluten meal (RGM) as an alternative protein source along with protease enzyme supplementation on growth performance, expression of nutrient transporter genes, nutrient digestibility, immune response and gut histomorphometry of broiler chicken. Proximate analysis of RGM revealed 923 g dry matter (DM), 500 g crude protein (CP), 69.2 g ether extract, 94.7 g crude fiber, 215.4 g nitrogen-free extract, 43.7 g ash, 6.20 g calcium, 7.80 g total phosphorus, 18.99 MJ gross energy and 12.68 MJ metabolizable energy per kg diet. Significant upregulation of nutrient transporter genes (PepT1, EAAT3 and mucin) and better growth performance was observed in the birds fed control diet which was statistically similar to the birds fed 150 g RGM compared to birds fed higher RGM levels. Histomorphometry of jejunum, nutrient digestibility, and immune response of birds did not reveal any significant effect of RGM or protease enzyme supplementation. However, the inclusion of RGM up to 150 g/kg diet resulted in significant decline of feed cost/kg live weight gain, dressed meat yield and eviscerated meat yield by 13.13%, 12.99% and 13.36%, respectively compared to control. Thus, it was concluded that the inclusion of 150 g RGM/kg diet in broiler chicken ration has no adverse effects on the growth pattern of birds and can be used for least-cost feed formulation for chicken.

This study explored the transcriptome of lamb testis cells infected with sheeppox virus (SPPV) wild strain (WS) and vaccine strain (VS) at an immediate-early time. Most of the differentially expressed genes (DEGs) and differentially expressed highly connected (DEHC) gene network were found to be involved in SPPV-VS infection compared to SPPV-WS. Further, the signaling pathways were mostly involved in SPPV-VS infection than SPPV-WS. SPPV modulates the expression of several important host proteins such as CD40, FAS, ITGβ1, ITGα1, Pak1, Pak2, CD14, ILK leading to viral attachment and entry; immune-related DEGs such as MAPK, JNK, ERK, NFKB, IKB, PI3K, STAT which provide optimal cellular condition for early viral protein expression; and FOXO3, ATF, CDKNA1, TCF, SRF, BDNF which help in inducing apoptosis and MPTP, BAD and Tp53 inhibits apoptosis or cell death at the immediate-early time. The results captured the specific genes and enabled to understand distinct pathogenic mechanisms employed by VS and WS of SPPV.

Microbiologically gastrointestinal tract (GIT) is one of the most active ecosystems with rich diversity of microflora and this gut microbial ecosystem is very crucial for the development and maturation of the of GIT associated immune system. The probiotics mediate their effects by regulating various immune cells, such as T regulatory cells, effector lymphocytes, natural killer T cells, B cells, dendritic cells, and epithelial cells. The gut microbiota is very instrumental in the development and immunomodulation of mucosal immune system and any sort of impairment might result in development of microbiota-related diseases. There are two major mechanisms underlying the immunomodulatory actions of probiotics – regulation of gene expression and signaling pathways in the host cells. The immunomodulatory effect is achieved by: a) direct stimulation of residing immune cells in the GIT, which results in macrophage activation and enhanced phagocytosis, b) modulation of enzyme activity by changing the microbial metabolism. On exposure to any foreign antigen an immune response is initiated by host gut mucosal immune system to maintain the homeostasis partly by adaptive immune response and partly by inducing inflammation. The advancement in the knowledge of intestinal microbiota as a result of metagenomics strategies has provided us a greater understanding of underlying mechanisms of how gut microorganisms affect the body functions. Significant amount of encouraging data pertaining to studies on humans and animal models show that supplementation of probiotics are promising approaches for prevention and treatment of GIT and immune disorders. The effects of probiotics have been observed beyond GIT and the interaction between GIT and central nervous system have revealed the role of neurochemical signalling in gut homeostasis and mental health. However, there is uncertainty in reproducibility of the effects of probiotic supplementation in animal or human nutrition and also there is no information whether the probiotics used in animal nutrition enter the human food chain or not.

CISPR/Cas9 system is a natural immune mechanism adopted by bacteria and archaea on exposure to invading phages and plasmids. The field of genome editing has been revolutionized with the advent of CRISPR/Cas9 technology. The CRISPR/Cas9 based gene editing has offered a promising therapeutic platform for many animal and human diseases, particularly viral diseases because viruses evolve constantly and hence escape vaccine-induced immunity. The targeted genome editing by RNA-guided nucleases is rapid, easy, economical, and efficient compared to previous editing technologies. It not only helps in the direct destruction of viruses, but also helps us understand the host-virus interactions, gene functions, and develop recombinant vaccines. It has been widely experimented in the field of antiviral therapy, starting with HIV in 2013 to SARS CoV-2 recently, with a series of modifications in structure and composition of CRISPR/Cas9 and delivery mechanisms to achieve the ever-increasing promising results. Herein, this review focused on the origin of CRISPR/Cas9 system, mechanism of action, advantages over existing gene-editing tools, its progress in antiviral therapy, vaccine development, delivery approaches, and challenges faced in the application of CRISPR/Cas9.

This research studied the effects of flaxseed meal (FSM) feeding for different durations on growth performance, fatty acid profile, oxidative stability of meat, and serum biochemical profile of broiler chicken. In basal diet 100 g FSM replaced soybean meal. The FSM based diet was fed for different durations resulting in six dietary treatments viz. T1 (0-5 weeks), T2 (1-5 weeks), T3 (2-5 weeks), T4 (3-5 weeks), T5 (4-5 weeks), and T6 (without FSM). The results revealed significant negative effects of FSM feeding beyond 3 weeks duration (2-5 weeks) on the weight gain, feed efficiency, production efficiency factor, protein efficiency ratio, and energy efficiency ratio of broiler chicken. Significant improvement of fatty acid profile of chicken meat was observed by FSM feeding up to 3 weeks only. Increasing the FSM feeding beyond 1 week in case of thigh meat and 2 weeks in case of breast meat significantly decreased the antioxidant capacity of broiler chicken meat. The lipid oxidation of broiler chicken meat increased significantly by feeding FSM beyond 2 weeks. Increase in the duration of FSM feeding has significantly decreased the serum triglyceride, cholesterol, cardiac risk ratio, atherogenic coefficient, and atherogenic index of plasma, though, the decline was not significant beyond the 2 weeks (3-5 weeks) feeding duration. The progressive increase in serum HDL cholesterol, serum antioxidant enzyme activities, and MDA concentration was observed with increase of FSM feeding duration. Thus, the 100 g FSM feeding for 2 weeks duration (3-5 weeks) has no negative effect on the growth performance with better health indices and serum biochemical profile of broiler chicken. However, increasing the duration of feeding beyond 1 week (4-5 week) exerts negative effects on the oxidative stability of meat and serum antioxidant enzyme profile.

This study investigated growth performance, growth efficiency, lipid composition, lipid metabolism, health indices, and serum lipid chemistry of broiler chicken fed flaxseed meal (FSM) and Cr. Five dietary treatments were formulated – T1 (control), T2 (100 g FSM), T3 (100 g FSM + 0.5 ppm Cr), T4 (100 g FSM + 1.0 ppm Cr), and T5 (100 g FSM + 1.5 ppm Cr). Each treatment was assigned six replicate groups of day-old broiler chicks with eight birds in each. Feeding of 100 g FSM exerted negative effects on the growth performance during starter phase only (0-3 weeks) and overall growth efficiency parameters in broiler chicken, whereas, Cr supplementation reversed these negative effects. 100 g FSM reduced abdominal fat in chicken and Cr supplementation linearly decreased it with minimum at 1.5 ppm Cr. Feeding of 100 g FSM favourably improved the activities of lipid metabolism enzymes which resulted in improved fatty acid profile and health indices of chicken meat. No significant effect of Cr supplementation was observed on lipid metabolism, fatty acid profile, and health indices of chicken meat. 100 g FSM decreased serum total cholesterol, triglyceride, cardiac risk ratio, atherogenic coefficient, and atherogenic index of plasma, whereas, Cr supplementation decreased these parameters linearly with increasing levels. Antioxidant enzyme activities and lipid peroxidation were increased by FSM, whereas, Cr supplementation linearly decreased them with increasing levels; and inverse trend was observed in serum HDL cholesterol levels. This study concludes that feeding of 100 g FSM exert negative effects on growth performance of young chicken (0-3 weeks), favourably alter lipid metabolism which results in improved fatty acid profile and health indices of chicken meat. It improves the serum lipid profile and atherogenic indices in broiler chicken, but negatively affects the oxidative stability of lipids. However, Cr supplementation at 1.5 ppm level in diet successfully overcomes the negative effects of FSM feeding on growth performance and lipid oxidative stability.

This study investigated growth performance, growth efficiency, lipid composition, lipid metabolism, health indices, and serum lipid chemistry of broiler chicken fed flaxseed meal (FSM) and Cr. Five dietary treatments were formulated – T1 (control), T2 (100 g FSM), T3 (100 g FSM + 0.5 ppm Cr), T4 (100 g FSM + 1.0 ppm Cr), and T5 (100 g FSM + 1.5 ppm Cr). Each treatment was assigned six replicate groups of day-old broiler chicks with eight birds in each. Feeding of 100 g FSM exerted negative effects on the growth performance during starter phase only (0-3 weeks) and overall growth efficiency parameters in broiler chicken, whereas, Cr supplementation reversed these negative effects. 100 g FSM reduced abdominal fat in chicken and Cr supplementation linearly decreased it with minimum at 1.5 ppm Cr. Feeding of 100 g FSM favourably improved the activities of lipid metabolism enzymes which resulted in improved fatty acid profile and health indices of chicken meat. No significant effect of Cr supplementation was observed on lipid metabolism, fatty acid profile, and health indices of chicken meat. 100 g FSM decreased serum total cholesterol, triglyceride, cardiac risk ratio, atherogenic coefficient, and atherogenic index of plasma, whereas, Cr supplementation decreased these parameters linearly with increasing levels. Antioxidant enzyme activities and lipid peroxidation were increased by FSM, whereas, Cr supplementation linearly decreased them with increasing levels; and inverse trend was observed in serum HDL cholesterol levels. This study concludes that feeding of 100 g FSM exert negative effects on growth performance of young chicken (0-3 weeks), favourably alter lipid metabolism which results in improved fatty acid profile and health indices of chicken meat. It improves the serum lipid profile and atherogenic indices in broiler chicken, but negatively affects the oxidative stability of lipids. However, Cr supplementation at 1.5 ppm level in diet successfully overcomes the negative effects of FSM feeding on growth performance and lipid oxidative stability.

A study was conducted to evaluate the effects of different levels and sources of dietary copper (Cu) in broiler chicken. The experimental design was 3x4 factorial with three levels of Cu (8, 12, 16 ppm) and four sources (inorganic – IC, organic – OC, green nano – GNC, and market nano – MNC) resulting in 12 dietary treatments. The GNC was synthesised in the laboratory. A total of 480 day old chicken of same hatch and uniform body weight were procured and divided randomly in 12 treatment groups having 5 replicates with 8 birds in each (40 birds/treatment). The results revealed significantly higher body weight gain and feed intake in birds supplemented with GNC or MNC at 16 ppm Cu level. The better feed efficiency was observed at 16 ppm level of GNC or MNC. However, no significant effects of Cu levels or sources were observed on the carcass characteristics and cutup parts of broiler chicken. Similarly, enhanced cell mediated immune response measured as response to PHAP was observed in birds supplemented with GNC followed by MNC and at 16 ppm level. The humoral immune response, measure as response against sheep red blood cells, was higher in birds supplemented with MNC or GNC at 16 ppm level. Thus, this study concludes that supplementation of Cu in broiler chicken at 16 ppm level of nano form improves the growth and feed efficiency along with an enhanced immunity. The green nano Cu synthesised in this study was equally better in improving growth performance and immunity of birds as market nano Cu. However, green nano Cu was superior to market nano Cu in improving the cell mediated immunity of broiler chicken.

The objective of this present study was to investigate the potentiality of prebiotics (mannan oligosaccharides-MOS and fructo-oligosaccharides-FOS) in replacement of antibiotic growth promoter and their relationship with physico-chemical indices, antioxidant and oxidative stability and carcass traits of broiler chickens meat. Accordingly, 240 day-old broiler chicks of uniform body weight divided in 6 treatment groups with 5 replicate each (5 × 6 = 30) having 8 birds in each replicate. Six corn based dietary treatments were formulated viz. T 1 (control diet), T 2 (T 1 + Bacitracin methylene di-salicylate @ 0.002%), T 3 (T 1 + 0.1% MOS), T 4 (T 1 + 0.2% MOS), T 5 (T 1 + 0.1% FOS), and T 6 (T 1 + 0.2% FOS). Significant ( p < 0.05) increase in cut up part yields (%) and reduction in cholesterol and fat content in T 4 (0.2% MOS) group. The water holding capacity (WHC) and extract release volume (ERV) were increase ( p < 0.05) in 0.1 or 0.2% MOS supplemented group. DPPH (1, 1-diphenyl-2-picrylhydrazy) was higher ( p < 0.05) and lipid oxidation (free fatty acid and thio-barbituric acid reactive substances) was lower ( p < 0.05) in T 4 group. The standard plate count (SPC), staphylococcus and coliform counts were decreased ( p < 0.05) in T 3 or T 4 group. Thus, it can be concluded that mannan oligosaccharides (MOS) may be incorporated at 0.2% level in diet for improved physico-chemical indices, antioxidant and oxidative stability and carcass characteristics of broiler chickens meat and it may be suitable replacer of antibiotic growth promoter.

This study investigated the role of dietary prebiotic mannan-oligosaccharides (MOS), and probiotic Bifidobacterium bifidum (BFD) in lipid metabolism, deposition, and consequent health indices in broiler chicken. The supplementation of 0.2% MOS along with either 10 6 or 10 7 CFU BFD/g feed resulted in downregulation of Acetyl-CoA carboxylase, fatty acid synthase, sterolregulatory element binding protein-1, and apolipoprotein B100; and up-regulation of peroxisome proliferator activated receptor-α AMP-activated protein kinase α-1, and stearoyl CoA (∆9) desaturase-1 hepatic expression in broiler chicken. The birds supplemented with 0.2% MOS along with either 10 6 or 10 7 CFU BFD/g feed depicted lower body fat percentage, palmitic acid, stearic acid, and saturated fatty acid contents, whereas, higher palmitoleic acid, oleic acid, and MUFA contents were observed. The ∆9-desaturase indices of chicken meat have shown higher values; and elongase index (only thigh) and thioesterase index have shown lower values in birds supplemented with 0.2% MOS along with either 10 6 or 10 7 CFU BFD/g feed. The meat health indices such as Polyunsaturated fatty acids (PUFA)/Saturated fatty acids (SFA) ratio, Mono-saturated fatty acids (MUFA)/SFA ratio, unsaturated fatty acids (UFA)/SFA ratio, hypocholesterolemic/hypercholesterolemic fatty acid ratio, saturation index, atherogenic index, thrombogenic index, and hypercholesterolemic fatty acid content were positively improved in birds supplemented with 0.2% MOS along with either 10 6 or 10 7 CFU BFD/g feed. Similarly, the birds supplemented with 0.2% MOS along with either 10 6 or 10 7 CFU BFD/g feed have shown lower serum triglyceride and total cholesterol levels along with higher high density levels and improved serum health indices cardiac risk ratio, atherogenic coefficient, and, atherogenic index of plasma.

CISPR/Cas9 system is a natural immune mechanism adopted by bacteria and archaea on exposure to invading phages and plasmids. The field of genome editing has been revolutionized with the advent of CRISPR/Cas9 technology. The CRISPR/Cas9 based gene editing has offered a promising therapeutic platform for many animal and human diseases, particularly viral diseases because viruses evolve constantly and hence escape vaccine-induced immunity. The targeted genome editing by RNA-guided nucleases is rapid, easy, economical, and efficient compared to previous editing technologies. It not only helps in the direct destruction of viruses, but also helps us understand the host-virus interactions, gene functions, and develop recombinant vaccines. It has been widely experimented in the field of antiviral therapy, starting with HIV in 2013 to SARS CoV-2 recently, with a series of modifications in structure and composition of CRISPR/Cas9 and delivery mechanisms to achieve the ever-increasing promising results. Herein, this review focused on the origin of CRISPR/Cas9 system, mechanism of action, advantages over existing gene-editing tools, its progress in antiviral therapy, vaccine development, delivery approaches, and challenges faced in the application of CRISPR/Cas9.

A suitable method for the extraction of nucleic acids should be efficient, sensitive, rapid and simple. Moreover, ideally, good method should yield pure nucleic acid-free from any contaminant inhibitors. Several methods have been reported for viral deoxyribonucleic acid (DNA) isolation but limited information is available on quick and simple isolation of Sheeppox virus (SPPV) genomic DNA in cell culture. In this study, the healthy Vero cells and primary lamb testis cells were infected with SPPV strains such as SPPV-Jaipur, SPPV-Ranipet and SPPV-Roumanian Fanar (RF) and harvested when it exhibited clear cytopathic effect (CPE) in culture. Four different DNA extraction methods i.e., (i) Phenol/chloroform/Isoamyl alcohol method, (ii) Cell lysis buffer method, (iii) Proteinase-k method, and (iv) commercial nucleic acid extraction kit was used to extract optimum yield of viral genomic DNA from clarified culture supernatant of harvested SPPV virus. The DNA sample was characterized using the Nanodrop spectrophotometer and agarose gel electrophoresis. Significantly (p<0.05) higher yield of SPPV genomic DNA was obtained in proteinase-k method which was about 3-5 times more than other methods. Among these methods, proteinase-k protocol was found to be comparatively very effective method in terms of yield of viral genomic DNA, and was free from PCR inhibitors.

Antibiotics have revolutionized the intensive poultry production system as a feed additive by promoting growth, production and meat quality through improving gut health and reduction of sub-clinical infections during last five decades. However, currently, the usage of antibiotics in poultry production is under severe scientific and public scrutiny, because antibiotic growth promoter (AGP) has been linked to the possible development of antibiotic-resistant pathogens, which may pose a threat to human health. After European Union ban on in feed antibiotics as growth promoter in poultry, since 2006, prebiotics offer a potential substitute to in feed antibiotics. In this effort, the objective of this present study was to investigate the potentiality of prebiotics (mannan oligosaccharides-MOS and fructo-oligosaccharides-FOS) in replacement of antibiotic growth promoter and their relationship with physio-biochemical indices, antioxidant and oxidative stability and carcass traits of broiler chickens meat. 240 day-old broiler chicks (1 d) of uniform body weight were divided into 30 replicate groups having 8 birds in each. Six corn based dietary treatments were formulated viz. T1 (control diet), T2 (T1 + Bacitracin methylene di-salicylate @ 20 mg/kg diet), T3 (T1 + 0.1% MOS), T4 (T1 + 0.2% MOS), T5 (T1 + 0.1% FOS), and T6 (T1 + 0.2% FOS). Significant (P<0.05) increase in cut up part yields (%) and reduction in cholesterol and fat content in T4 (0.2 % MOS) group. The water holding capacity (WHC) and extract release volume (ERV) were increase (P<0.05) in 0.1 or 0.2 % MOS supplemented group. DPPH (1, 1-diphenyl-2-picrylhydrazy) was higher (P<0.05) and lipid oxidation (free fatty acid and thio-barbituric acid reactive substances) was lower (P<0.05) in T4 group. The standard plate count (SPC), staphylococcus and coliform counts were decreased (P<0.05) in T3 or T4 group. Thus, it can be concluded that mannan oligosaccharides (MOS) may be incorporated at 0.2% level in diet for improved physio-biochemical indices, antioxidant and oxidative stability and carcass characteristics of broiler chickens meat and it may be suitable replacer of antibiotic growth promoter.

Present study was carried out with the objective of investigating the role of green synthesized nano Se (GNS) in growth performance, digestibility of minerals, immunity, stress alleviation, antioxidant status, and body Se content of broiler chicken raised under hot and humid environment with respect to market nano Se (MNS) and inorganic Se. The experimental design was 3 × 3 factorial, in which three levels (0.15, 0.20, and 0.25 ppm) and three sources (inorganic, green nano, and market nano) of Se resulted in nine treatments viz. IS-0.15, GNS-0.15, MNS-0.15, IZ-0.20, GNS-0.20, MNS-0.20, IS-0.25, GNS-0.25, and MNS-0.25 (IS: inorganic Se, GNS: green nano Se, MNS: market nano Se). A total of 432 broiler chicken were divided among nine treatments with six replicates of birds per treatment (8 birds/replicate). Results of present study revealed significantly better growth performance of birds supplemented with 0.25 ppm nano Se. The supplementation of 0.25 ppm nano Se improved the immune response and lymphoid organ development of birds. Significantly higher Se and nitrogen digestibility coefficients, serum antioxidant activity and decline of Heterophil: Lymphocyte ratio and expression of HSP70 gene were observed in birds supplemented with 0.25 ppm Se and nano source of Se compared to inorganic Se. Significantly higher Se concentration in liver and breast muscle and higher serum Se concentration were observed in birds fed 0.25 ppm nano Se. The liver Se concentration was much higher than that of breast muscle. However, the nano Se synthesized by green method in this study did not differ significantly from the chemically synthesized nano Se. It was concluded that 0.25 ppm Se and nano form of Se are superior to lower levels and inorganic form of Se, respectively, in improving the immunity, growth, antioxidant status, and in stress alleviation of broiler chicken. However, GNS is equally efficient as chemically synthesized MNS.

This study investigated the effects of dietary Bifidobacterium bifidum (BFD) and mannan‐oligosaccharide (MOS), as a synbiotic, on the production performance, gut microbiology, serum biochemistry, antioxidant profile and health indices of broiler chicken. Six dietary treatments were T1 (negative control), T2 (positive control‐20 mg antibiotic BMD kg−1 diet; BMD: bacitracin methylene disalicylate), T3 (0·1% MOS + 106 CFU BFD per g feed), T4 (0·1% MOS + 107 CFU BFD per g feed), T5 (0·2% MOS + 106 CFU BFD per g feed) and T6 (0·2% MOS + 107 CFU BFD per g feed). Significantly (P < 0·01) better growth performance and efficiency was observed in birds supplemented with 0·2% MOS along with 106 CFU BFD per g of feed compared to BMD and control birds. Supplementation with 0·2% MOS along with either 106 or 107 CFU BFD per g feed reduced (P < 0·01) the gut coliform, Escherichia coli, total plate count, and Clostridium perfringens count and increased the Lactobacillus and Bifidobacterium count. Significantly (P < 0·01) higher serum and liver antioxidant enzyme pool, serum HDL cholesterol and lower serum glucose, triglyceride, total cholesterol, cardiac risk ratio, atherogenic coefficient and atherogenic index of plasma were observed in birds supplemented with 0·2% MOS along with 106 CFU BFD per g of feed compared to control or BMD supplemented birds. Better production performance, gut microbial composition, serum biochemistry, antioxidant profile and health indices were depicted by broiler chicken supplemented with 0·2% MOS and 106 CFU BFD per g of feed.

An experiment was conducted to determine the effect of a synbiotic supplementation on immune response, expression of nutrient transporter genes and gut health status of broiler chickens. Day-old chicks (n=240) were randomly assigned to six dietary treatments (each with 5 replicates of 8 birds), and fed a basal diet alone (T-1) or supplemented with bacitracin methylene di-salicylate (BMD) at 20 mg/kg diet (T-2), Lactobacillus acidophilus (LBA) at 10(6) cfu/g + 0.1% mannan-oligosaccharides (MOS; T-3), LBA at 10(7) cfu/g + 0.1% MOS (T-4), LBA at 10(6) cfu/g + 0.2% MOS (T-5), LBA at 10(7) cfu/g + 0.2% MOS (T-6). Results of the 6 weeks study indicated that the haemagglutination titre to sheep RBC and foot pad index following sensitization with phytohaemagglutinin-P were significantly (P<0.05) higher in T-5 and T-6 groups. Significant increases (P<0.05) were observed in serum proteins and decreases in aspartate transaminase and alanine transaminase, creatinine, uric acid, total cholesterol, high- and low density-lipoprotein concentrations in T-5 and T-6 group. Villus height and crypt depth were increased (P<0.05) in T-5 and T-6 groups. The mRNA expression of glucose transporters-5 (GLUT5), sodium glucose transporter-1 (SGLT1) and peptide transporter-1 (PepT1) gene in ileum, measured at 14 d of age, were significantly (P<0.05) upregulated in T-5 and T-6 groups. The results of the present study indicated that inclusion of a synbiotic containing 0.2% mannan-oligosachharide along with L. acidophilus (at 10(6) cfu/g) in the diet improved the immune response, serum biochemical parameters, intestinal morphometry and expression of nutrient transporter genes of broiler chickens.

The present study investigated the effects of Lactobacillus acidophilus (LBA) and mannan-oligosaccharides (MOS) supplementation on the production performance, serum biochemistry, antioxidant profile, health indices, meat quality, and lipid oxidative stability of broiler chicken. A total of 252 commercial broiler chickens at 1 d old of uniform body weight were randomly allocated to 6 maize-soybean-based dietary treatments: T1 (control diet), T2 ( antibiotic bacitracin methylene di-salicylate [BMD] at 20 mg/kg diet), T3 (MOS at 0.1% + LBA at 106 CFU/g feed), T4 (MOS at 0.1% + LBA at 107 CFU/g feed), T5 (MOS at 0.2% + LBA at 106 CFU/g feed), and T6 (MOS at 0.2% + LBA at 107 CFU/g feed). Each treatment was assigned to 6 replicates of 7 birds. The samples for meat quality and serum biochemistry analysis were taken from 12 birds per treatment (2 birds/replicate). The results revealed better (P < 0.01) growth performance and production efficiency of birds fed either T5 or T6 diet compared to control or BMD supplemented diet and BMD-supplemented birds superseded the control birds. Higher (P < 0.01) serum and liver antioxidant enzyme activities, meat antioxidant capacity (2, 2-azinobis-3-ethylbenzothiazoline-6-sulfonic acid [ABTS] and 1, 1-diphenyl-2-picrylhydrazyl [DPPH] assays], serum total protein, high-density lipoproteins (HDL) cholesterol (P < 0.05), and globulin levels (P < 0.01) were observed in birds fed either T5 or T6 diet compared to control or BMD supplemented birds, whereas, lower lipid oxidation (P < 0.01), cardiac risk ratio, atherogenic coefficient, atherogenic index of plasma, serum glucose, triglyceride, total cholesterol levels (P < 0.01), and serum albumin-to-globulin ratio (P < 0.05) were observed in the chickens. The pH of meat from birds fed T4, T5 or T6 diet was lower (P < 0.01) compared to control and other treatments. The extract release volume (ERV), water holding capacity (WHC), and protein content of meat were higher (P < 0.05) in birds fed either T5 or T6 diet compared to control or BMD supplemented birds. Thus, it was concluded that the supplementation of 0.2% MOS along with LBA at 106 CFU/g is optimum for better growth performance, serum biochemistry, antioxidant profile, health indices, meat quality, and lipid oxidative stability of broiler chickens.

The outbreak of coronavirus disease 2019 (COVID-19) as a pandemic has shaken the global health system and economy by their roots. This epidemic is still spreading and showing no signs of decreasing trend. Vaccination could be the only effective and economical means to control this pandemic. A number of research institutions and pharmaceutical companies have plunged into the race of vaccine development against COVID-19 which are in various stages of development. An intriguing fact of coronavirus infections is that in every decade of the 21st century there is a new major coronavirus epidemic, namely, severe acute respiratory syndrome (SARS) in 2002, Middle East respiratory syndrome (MERS) in 2012, and now COVID-19; and such epidemics are expected in future too. Since most of the biological characteristics of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are still obscure, the scientists are relying on the information available on SARS-CoV and to some extent on MERS-CoV for designing and developing COVID-19 vaccines. But there is a need of vigorous testing for immunogenicity, safety, efficacy, and level of protection conferred in the hosts. This review focuses on the challenges and prospects of vaccine development against COVID-19. It highlights seriousness, bottlenecks in vaccine development, possible vaccine candidates, different vaccine strategies, safety evaluation issues, and vaccine production processes pertaining to COVID-19 based on the knowledge acquired on SARS and MERS vaccine development in the past.