Potential Replacements for Antibiotic Growth Promoters in Poultry: Interactions at the Gut Level and Their Impact on Host Immunity

Phloretin supplementation ameliorates intestinal injury of broilers with necrotic enteritis by alleviating inflammation, enhancing antioxidant capacity, regulating intestinal microbiota, and producing plant secondary metabolites

The present study aimed to explore the effects of dietary phloretin (PT) on growth performance, immune response, and intestinal function in broilers with necrotic enteritis (NE). A total of 288 1-day-old Arbor Acres chicks were assigned to 3 groups, with 8 replicates per group and 12 chicks per replicate. Over 6 weeks, birds were fed a basal diet or the same diet supplemented with 200 mg/kg phloretin. Birds in the challenged groups were inoculated with coccildia during d 7 to 9 and Clostridium perfringens(CP) during d 14 to 18. Results showed that CP and coccidia challenge reduced the average daily gain and average daily feed intake, increased the feed conversion ratio of broilers, induced inflammation and oxidative stress, and inhibited mRNA expression levels for genes associated with intestinal barrier and nutrient transporters (P < 0.05). PT addition to the feed improved growth performance at early phase improved intestinal morphology, and elevated antioxidant capacity via increasing the activity of total antioxidant capacity and superoxide dismutase in the ileum in broilers with necrotic enteritis (P < 0.01). Dietary PT regulated the intesetinal immune function as observed by the increases in the content of secretory IgA in the ileum and decreased cytokines (Interleukin-1β, Interleukin-10) (P < 0.05). Moreover, NE infection significantly disrupted the balance of intestinal flora, and led to a lower level of short-chain fatty acids such as butyric acid concentration in the ileum, while PT improved the microbiota structure, and increased the intestinal acetic acid and butyric acid concentration (P < 0.001). Furthermore, metabolomics analysis indicated PT treatment improve plant secondary metabolites contents like phloretin 2'-o-glucuronide. Additionally, we observed a significant positive correlation among PT, Ligilactobacillus and butyric acid, and a positive correlation between Ligilactobacillus and plant secondary metabolites. Overall, PT supplementation could improve growth performance and ameliorate intestinal injury in broilers with necrotic enteritis by enhancing the antioxidant capacity and immune function, regulating intestinal flora structure and producing plant secondary metabolites.

Benzoic Acid, Enterococcus faecium, and Essential Oil Complexes Improve Ovarian and Intestinal Health via Modulating Gut Microbiota in Laying Hens Challenged with Clostridium perfringens and Coccidia

Intestinal disease is becoming increasingly prevalent in poultry production; however, the effect of BEC in laying hens challenged with C. perfringens and coccidia is limited. This study aimed to investigate the effects of dietary supplementation with BEC on intestinal and ovarian health in laying hens challenged with C. perfringens and coccidia. A total of 80 Lohmann gray hens (35 weeks) were randomly assigned to two dietary groups supplemented with BEC (0 or 1000 mg/kg). Each group contained 40 replicates, with one bird each (one hen per cage). During the sixth week of the trial, half of the laying hens in each group (n = 20) were administered 40 mL C. perfringens (2.5 × 1010 CFU/mL) and 0.15 mL coccidia (55,000 sporangia/mL), while the other half (n = 20) were administered 40 mL phosphate-buffered saline (PBS). The results indicated that those challenged with C. perfringens and coccidia had severely damaged jejunal and ovarian histopathological morphology, increased oxidative damage, decreased cecal acetic acid and butyric acid content (p < 0.05), and resulted in lower gut microbial richness and diversity. The diet of 1000 mg/kg BEC reduced the jejunal and ovarian pathological damage and oxidative damage, increased short-chain fatty acids (SCFAs) content, and enhanced gut microbial richness and diversity (p < 0.05) in laying hens challenged with C. perfringens and coccidia. Furthermore, the positive effects of BEC on intestinal health were associated with changes in gut microbial composition and structure. In summary, dietary supplementation with BEC has the potential to reduce the severity of intestinal and ovarian damage caused by challenges posed by C. perfringens and coccidia through the modulation of gut microbiota.

Impact of Rumex nepalensis on Performance, Blood Markers, Immunity, Intestinal Microbiology and Histomorphology in Broiler Chicken

The study investigated the impact of utilizing Rumex nepalensis leaf powder (RNL) as a phytogenic feed additive on performance, blood markers, intestinal microbiology and histomorphology in broiler chicken. One hundred eighty day-old Cobb broiler chicks were randomly divided into four treatment groups having three replicates with fifteen birds each. Four iso-caloric and iso-nitrogenous diets primarily based on maize-soybean were formulated, viz., CN (Control)-fed basal diet only; RNL2.5 (basal diet + 2.5 g/kg RNL); RNL5 (basal diet + 5 g/kg RNL); and RNL10 (basal diet + 10 g/kg RNL). The results revealed a significant (p < 0.05) increase in body weight gain and feed conversion ratio in dietary treatments compared to CN with best values in RNL10 followed by RNL5. The blood markers like glucose, total protein, creatinine, alanine transaminase (ALT) and aspartate transaminase (AST) showed no significance (p > 0.05) among all the treatments, however total cholesterol significantly (p < 0.05) decreased in RNL5 and RNL10 as against CN. Regarding immune parameters, immunoglobulin G (IgG) and immunoglobulin M (IgM) levels significantly (p < 0.05) enhanced in RNL5 and RNL10. Antioxidant enzyme status showed that superoxide dismutase (SOD) increased and malondialdehyde (MDA) decreased significantly (p < 0.05) in RNL10 compared to CN. Gut health in terms of cecal microbiology and histomorphology of duodenum and jejunum were altered by inclusion of RNL in the broiler diet. A significant decrease (p < 0.05) in coliform count was recorded by incorporation of dietary treatments with highest reduction in RNL10. Lactobacillus count and total viable count did not vary significantly (p > 0.05) among dietary treatments and CN. Duodenal and jejunal villus height and villus height/crypt depth ratio were significantly (p < 0.05) increased in RNL5 and RNL10 compared to RNL2.5 and CN. Thus, it could be concluded that inclusion of Rumex nepalensis leaf powder in the diet resulted in improved performance and better immuno-antioxidant status of broilers. Further, an improvement in the gut health was observed in terms of positive effects on cecal microbiota and intestinal histomorphology of broiler chickens.

Impacts of dietary supplementation of chitosan nanoparticles on growth, carcass traits nutrient digestibility, blood biochemistry, intestinal microbial load, and meat quality of broilers

This study explores the impact of chitosan nanoparticles (CNP) on the performance, nutrient digestibility, blood biochemical, immunity, microbial load, carcass traits, and meat attributes of broilers. A total of 200 7-d-old Cobb chicks were distributed to 4 groups, each replicated 5 times, with 10 birds in each replicate. The experimental diets were as follows: First group was fed a basal diet only (control); 2nd, 3rd, and 4th groups received a basal diet supplemented with 0.2, 0.3, and 0.4 g CNP/kg of feed, respectively. Results showed that the body weight (BW) and body weight gain significantly improved (P < 0.05) in the birds belonging to the 0.4 CNP group compared to the other groups. The best feed efficiency (feed conversion ratio [FCR]) was found in the group supplemented with a 0.4-g CNP/kg diet. The digestibility coefficients for dry matter and crude protein were significantly higher, and ether extract was significantly lower in the 0.4 g CNP/kg group than in other groups (P < 0.05). Broiler birds of the 0.4 CNP group had significantly (P < 0.05) reduced serum cholesterol, AST, and ALT levels. The humoral immunity (increased serum IgG and IgM levels) tended to improve in birds fed 0.3 and 0.4 g CNP/kg of feed. Compared to the control, total bacterial load and coliform count decreased significantly (P < 0.05) by supplementing 0.4 g CNP in the diet. The dressing weight, breast weight, and abdominal fat % were altered in birds receiving dietary 0.4 g CNP/kg. The treatment with CNP at 0.4 g/kg feed enhanced the broiler meat quality by increasing the values for water holding capacity, ABTS [2, 2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid)], DPPH (2,2-diphenyl-1-picrylhydrazyl) while reducing the thiobarbituric acid reactive substances (TBARS) value. Based on the results above, it could be concluded that CNP supplementation at 0.4 g/kg is recommended as a beneficial feed additive for broiler chickens.

Nutrition and Metabolism: Foundations for Animal Growth, Development, Reproduction, and Health

Consumption of high-quality animal protein plays an important role in improving human nutrition, growth, development, and health. With an exponential growth of the global population, demands for animal-sourced protein are expected to increase by 60% between 2021 and 2050. In addition to the production of food protein and fiber (wool), animals are useful models for biomedical research to prevent and treat human diseases and serve as bioreactors to produce therapeutic proteins. For a high efficiency to transform low-quality feedstuffs and forages into high-quality protein and highly bioavailable essential minerals in diets of humans, farm animals have dietary requirements for energy, amino acids, lipids, carbohydrates, minerals, vitamins, and water in their life cycles. All nutrients interact with each other to influence the growth, development, and health of mammals, birds, fish, and crustaceans, and adequate nutrition is crucial for preventing and treating their metabolic disorders (including metabolic diseases) and infectious diseases. At the organ level, the small intestine is not only the terminal site for nutrient digestion and absorption, but also intimately interacts with a diverse community of intestinal antigens and bacteria to influence gut and whole-body health. Understanding the species and metabolism of intestinal microbes, as well as their interactions with the intestinal immune systems and the host intestinal epithelium can help to mitigate antimicrobial resistance and develop prebiotic and probiotic alternatives to in-feed antibiotics in animal production. As abundant sources of amino acids, bioactive peptides, energy, and highly bioavailable minerals and vitamins, animal by-product feedstuffs are effective for improving the growth, development, health, feed efficiency, and survival of livestock and poultry, as well as companion and aquatic animals. The new knowledge covered in this and related volumes of Adv Exp Med Biol is essential to ensure sufficient provision of animal protein for humans, while helping reduce greenhouse gas emissions, minimize the urinary and fecal excretion of nitrogenous and other wastes to the environment, and sustain animal agriculture (including aquaculture).