Comparative efficacy of tannin-free grain sorghum varieties for the control of necrotic enteritis caused by Clostridium perfringens in broiler chickens

Effects of replacing antibiotics with probiotics and antimicrobial peptides on performance, gut health, carcass traits, meat quality, and welfare in broilers infected with Eimeria and Clostridium perfringens

This study evaluated the effectiveness of antibiotic, probiotic, and antimicrobial peptide (AMP) supplements in mitigating adverse consequences of necrotic enteritis (NE) in broilers. In total, 720 one-day-old (Ross-308) male broiler chicks were randomly assigned to five distinct feeding regimens (each treatment consisting of six replicates of 24 birds) including: (1) negative control (NC), fed only basal diet; (2) positive control (PC); with C. perfringens challenge + basal diet; (3) CP-Ab: challenged + virginiamycin (Stafac® 500) at 200 g/ton, (4) CP-Pro: challenged + 200 g/ton B. subtilis PB6 (Clostat dry®) probiotic additive, and (5) CP-LS2: challenged and fed an antimicrobial peptide (LassoTide Plus®) at 200 g/ton. The NE challenge was induced by administering 10X coccidia vaccine on day 15 followed by inoculation with a pathogenic field strain of C. perfringens type G (1 × 108 CFU/ml/ bird; 1 ml) on days 19 and 20 through oral gavage. Feeding AMP and probiotic to the NE-affected broilers resulted in 23.93% and 19.70% respectively higher body weight gain and 76.59% and 70.27% lower mortality compared to the PC. Similarly, supplementation with AMP improved (P < 0.05) gut morphology, carcass yield (5.82%), meat water holding capacity (14.73%), and reduced cooking loss (10.01%), dripping loss (20.87%), and shear force (25%) as compared to the PC. Additionally, the excreta score, litter quality and welfare attributes were significantly ameliorated (P < 0.05) with AMP addition. In conclusion, the findings suggest that AMP outperformed both virginiamycin and probiotic, demonstrating its potential as a superior substitute for AGPs in broilers.

Comparative Effects of Antibiotic and Antimicrobial Peptide on Growth Performance, Gut Morphology, Intestinal Lesion Score, Ileal Microbial Counts, and Immune Status in Broilers Challenged with Necrotic Enteritis

This experiment aimed to compare the efficacy of an antimicrobial peptide (AMP) with a conventional antibiotic growth promoter (AGP) during necrotic enteritis (NE) challenge in broilers. In total, 720 1-day-old exclusively male broiler chicks (Ross-308) were allocated to five treatments, each with six replicates of 24 birds (n = 144/treatment), for 35 days. The treatments were as follows: (1) uninfected control (UC) with basal diet, (2) infected control (IC) with C. perfringens challenge and basal diet, (3) CP-AGP with C. perfringens challenge and 200 g/ton enramycin throughout trial, (4) CP-AMP1 with C. perfringens challenge and 200 g/ton AMP in all phases, and (5) CP-AMP2 with C. perfringens challenge and 300 g/ton AMP throughout experiment. To induce NE, the birds were predisposed with 10 × coccidia vaccine (day 15) followed by oral gavage of C. perfringens type G (1 ml; 1 × 108 CFU/ml/bird) at days 19 and 20. The results showed that AMP supplemented at 300 g/ton of diet improved body weight gain and FCR in both non-challenge (days 1-14) and challenge phases (days 15-35) as compared to the infected control (P < 0.05). Moreover, it also enhanced the livability and production efficiency factor (P < 0.0001). AMP at 300 g/ton also reduced NE lesion scores, and coccidia oocyst shedding, and positively affected intestinal morphology, gut microbial balance, immune organ weights, and HI titers against Newcastle disease (P < 0.0001). These findings suggest that AMP at 300 g/ton of diet could effectively mitigate NE and may be used as a viable substitute for AGPs in broiler diets during the NE challenge.

Growth performance, nutrients digestibility, intestinal microbiota and histology altered in broilers fed maize- or sorghum-based diets

This study aimed to evaluate the effect of varying levels of sorghum-based diets as an alternative to maize in broiler nutrition. A total of 320 one-day-old male Ross 708 broiler chickens were randomly allocated to four treatment groups (5 pens per treatment and 16 birds per pen), comprising a control group with a basal diet and groups receiving sorghum-based diets with 20%, 40%, and 100% maize replacement. The overall weight gain was significantly (p < 0.0001) higher in the control group, followed by 20%, 40%, and 100% sorghum replacement. Additionally, overall feed intake was significantly (p < 0.01) higher in the 20% sorghum replacement group compared to the control and other groups. Broilers fed sorghum-based diets exhibited a significantly (p < 0.01) increased feed conversion ratio. Carcass characteristics showed no significant differences between broilers fed corn and sorghum; however, the digestibility of crude protein and apparent metabolizable energy significantly (p < 0.01) increased in the 20% sorghum-corn replacement compared to the 40% and 100% replacement levels. Ileal villus height and width did not differ among the corn-sorghum-based diets, regardless of the replacement percentage. Furthermore, among the cecal microbiota, Lactobacillus count was significantly (p < 0.041) higher in the 20% corn-sorghum diet compared to the 40% and 100% replacement levels. These findings suggest that replacing corn up to 20% of corn with sorghum in broiler diet positively impact growth performance, gut health, nutrient digestibility, and cecal microbiota in broilers. However, larger replacements (40% and 100%) may have negative implications for broiler production and health.

The effects of a high-flavonoid corn cultivar on the gastrointestinal tract microbiota in chickens undergoing necrotic enteritis

The search for alternative therapies to antimicrobial growth promoters (AGP) in poultry production has gained momentum in the past years because of consumer preference and government restrictions on the use of AGP in animal production. Flavonoids are plant-derived metabolites that have been studied for their health-promoting properties that could potentially be used as an alternative to AGP in poultry. In a previous study, we showed that the inclusion of a flavonoid-rich corn cultivar (PennHFD1) in the diet improved the health of broilers undergoing necrotic enteritis. However, the mechanisms of action by which the PennHFD1-based diet ameliorated necrotic enteritis are unknown. This study describes the microbial diversity and composition of the jejunum and ileum of chickens co-infected with Eimeria maxima and Clostridium perfringens and treated with a high-flavonoid corn-based diet. Luminal content and mucosal samples from the jejunum and ileum were collected for DNA extraction, 16S rRNA amplicon sequencing and data analyses. The infection model and the dietary treatments significantly changed the alfa diversity indices (Mucosal samples: ASVs, P = 0.04; Luminal content samples: ASVs, P = 0.03), and beta diversities (Mucosal samples: P < 0.01, Luminal content: P < 0.01) of the ileal samples but not those of the jejunal samples. The microbial composition revealed that birds fed the high-flavonoid corn diet had a lower relative abundance of C. perfringens compared to birds fed the commercial corn diet. The treatments also changed the relative abundance of other bacteria that are related to gut health, such as Lactobacillus. We concluded that both the infection model and the dietary high-flavonoid corn changed the broilers' gut microbial diversity and composition. In addition, the decrease in the relative abundance of C. perfringens corroborates with a decrease in mortality and intestinal lesions due to necrotic enteritis. Collecting different segments and sample types provided a broader understanding of the changes in the gut microbiota among treatments.

A comprehensive review of experimental models and induction protocols for avian necrotic enteritis over the past 2 decades

Necrotic enteritis (NE) is a severe gastrointestinal disease that poses a significant threat to the poultry industry. It leads to progressive damage to the small intestine, reduced performance, increased mortality rates, and substantial economic losses. With the removal of antimicrobial agents from chicken feed, there is an urgent need to find alternative approaches for NE control. Various approaches, including vaccination, prebiotics, probiotics, and plant-derived products, have been utilized to address NE in poultry management. To evaluate the efficacy of these preventive measures against NE, successful induction of NE is crucial to observe effects of these approaches in related studies. This study presents a comprehensive overview of the methods and approaches utilized for NE reproduction in related studies from 2004 to 2023. These considerations are the careful selection of a virulent Clostridium perfringens strain, preparation of challenge inoculum, choice of time and the route for challenge inoculum administration, and utilization of one or more predisposing factors to increase the rate of NE occurrence in birds under experiment. We also reviewed the different systems used for lesion scoring of NE-challenged birds. By gaining clarity on these fundamental parameters, researchers can make informed decisions regarding the selection of the most appropriate NE experimental design in their respective studies.

Effect of arginine supplementation on the growth performance, intestinal health, and immune responses of broilers during necrotic enteritis challenge

The objective of this study was to evaluate the effect of 25% arginine supplementation as a functional amino acid in partially alleviating the detrimental effects of necrotic enteritis (NE) on the growth performance, serum biochemistry, gut integrity, and the relative gene expression of tight junction proteins and inflammatory cytokines in broilers during NE. Three hundred and sixty 1-day-old chicks were randomly allocated to 4 treatments in a 2 × 2 factorial arrangement -basal diet and 125% arginine diet, with or without NE challenge. NE was induced by inoculating 1 × 104Eimeria maxima sporulated oocysts on d 14 and 1 × 108 CFU/bird C. perfringens on d 19, 20, and 21. The NE challenge had a significant effect on the BWG (p < 0.05), FCR (p < 0.05), serum AST (p < 0.05), GLU (p < 0.05), and K+ (p < 0.05) levels, and intestinal permeability (p < 0.05) and jejunal lesion score (p < 0.05). A significant challenge × diet interaction effect was observed in the cecal tonsil CD8+: CD4+ T-cell ratio on d 21 (p < 0.05) and 28 (p < 0.05) and spleen CD8+: CD4+ T-cell ratio on d 21 (p < 0.05) and 35 (p < 0.05). Arginine supplementation significantly increased the CD8+: CD4+ T-cell ratio in uninfected birds but decreased the CD8+: CD4+ T-cell ratio in infected birds. On d 21, a significant interaction effect was observed on the relative expression of the iNOS gene (p < 0.05). Arginine supplementation significantly downregulated the expression of the iNOS gene in infected birds. A significant effect of the challenge (p < 0.05) was observed on the relative gene expression of the ZO-1 gene in the jejunum. NE challenge significantly downregulated the expression of the ZO-1 gene on d 21. In conclusion, arginine supplementation did not alleviate the depression in growth performance and disease severity during the NE challenge. However, arginine downregulated the expression of inflammatory cytokines and enzymes, preventing inflammatory injury to the tissues during NE. Hence, arginine might be supplemented with other alternatives to downregulate inflammatory response during NE in poultry.

Effect of guanidinoacetic acid on performance, egg quality, yolk fatty acid composition, and nutrient digestibility of aged laying hens fed diets with varying substitution levels of corn with low-tannin sorghum

A study was conducted to evaluate the efficiency of guanidinoacetic acid (GAA) in diets containing varying levels of corn replacement with low-tannin sorghum (LTS) for laying hens in the later stage of production. In a 12-wk study, a total of 288 laying hens at 52 wk of age were divided into 6 treatment groups. Each treatment group had 8 replicates, each of which consisted of 6 hens. A 2 × 3 factorial design was used to investigate the impact of substituting corn with LTS at 3 levels (100% corn, 50% LTS, and 100% LTS) with 2 doses of GAA supplementation (0 and 0.6 g/kg). The results indicate that there were interaction effects (P < 0.05) between diet type and GAA supplementation on protein digestibility and AMEn, with the GAA supplement being more effective in the 100% LTS group. Replacing corn with LTS at both levels had no negative effects on performance and metabolic profile. In contrast, the 100% LTS diet increased monounsaturated fatty acids in the yolk (P < 0.05), but decreased the yolk color index, the ratio of polyunsaturated fatty acids (PUFA) to saturated fatty acids (SFA) in the yolk, ileal digestibility of energy, and AMEn when compared to the 100% corn diet (P < 0.05). Regardless of the diet, dietary supplementation with GAA resulted in increases (P < 0.05) in shell-breaking strength, the PUFA to SFA ratio in egg yolk, and concentrations of creatine and nitric oxide in serum. There was also a decrease (P < 0.05) in serum malondialdehyde concentration with GAA supplementation. In conclusion, the positive effects of GAA on protein digestibility and AMEn were found to be more pronounced when corn was completely replaced with LTS. However, the positive effects of GAA on egg-laying performance, eggshell quality, antioxidant status, and yolk fatty acid composition remained consistent regardless of the extent to which corn was substituted with LTS.