Hyperimmune egg yolk antibodies developed against Clostridium perfringens antigens protect against necrotic enteritis

Valine and isoleucine deficiency in necrotic enteritis challenge impact growth performance, intestinal health, and muscle growth in broilers

Necrotic enteritis (NE), an enteric disease caused by Clostridium perfringens, and antagonistic effects due to dietary branched-chain amino acid (BCAA) imbalance are key factors that negatively affect chicken growth. The current study was conducted to investigate the effects of valine and isoleucine deficiency in NE challenged broilers. A total of 336 seven-d-old male Cobb 500 were allotted to four treatments with six replicates. The four treatments were as follows: (1) non-challenged control (NC; leucine:lysine = 1.31, valine:lysine = 0.73, and isoleucine:lysine = 0.63), (2) NE-challenged group (NE), (3) NE-challenged with 85 % valine deficiency group (NE-VAL; valine:lysine = 0.62), and (4) NE-challenged with 85 % isoleucine deficiency group (NE-ILE; isoleucine:lysine = 0.54). E. maxima and C. perfringens were administered on d 14 and 18, respectively, and the experiment lasted until d 21. The NE-VAL group had the lowest growth performance measurements compared to the other groups (P < 0.001). All NE-challenged groups had significantly reduced overall growth performance measurements compared to the NC group (P < 0.001). The NE-ILE group showed no difference in any of the measurements compared to the NE group. On d 21, the NE group had significantly increased intestinal permeability, jejunal lesion scores, C. perfringens colony counts, and jejunal chemokine and cytokine gene expression levels, along with decreased intestinal morphology compared to the NC group (P < 0.05). The NE-VAL group had significantly decreased breast muscle yield, reduced lean and total tissue weight, and increased expression levels of mechanistic target of rapamycin pathway and BCAA catabolism-related genes compared to the NE group (P < 0.05). This may explain why the NE-VAL group had the lowest growth performance, as the two negative effects of NE infection and valine deficiency are separated. In conclusion, the negative effects of NE challenge and valine deficiency were independent; valine deficiency showed a similar response to that exhibited by high leucine levels, despite reduced feed intake caused by NE challenge.

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.

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.

Comparison of necrotic enteritis effects on growth performance and intestinal health in two different meat-type chicken strains Athens Canadian Random Bred and Cobb 500

Chickens have undergone genetic improvements in the past few decades to maximize growth efficiency. However, necrotic enteritis (NE), an enteric disease primarily caused by C. perfringens, remains a significant problem in poultry production. A study investigated the differences in intestinal health between the nonselected meat-type chicken Athens Canadian Random Bred (ACRB) and the modern meat-type Cobb 500 broilers (Cobb) when challenged with experimental NE. The study utilized a 2 × 3 factorial arrangement, consisting of two main effects of chicken strain and NE challenge model (nonchallenged control, NC; NE challenge with 2,500/12,500 Eimeria maxima oocysts + 1 × 109C. perfringens, NE2.5/NE12.5). A total of 432 fourteen-day-old male ACRB and Cobb were used until 22 d (8 d postinoculation with E. maxima on d 14, dpi), and the chickens were euthanized on 6 and 8 dpi for the analysis. All data were statistically analyzed using a two-way ANOVA, and Student's t-test or Tukey's HSD test was applied when P < 0.05. The NE12.5 group showed significant decreases in growth performance and relative growth performance from d 14 to 20, regardless of chicken strain (P < 0.01). The ACRB group exhibited significant decreases in relative body weight and relative body weight gain compared to the Cobb group from d 14 to 22 (P < 0.01). On 6 and 8 dpi, both NE challenge groups showed significant decreases in intestinal villus height to crypt depth ratio, jejunal goblet cell count, and jejunal MUC2 and LEAP2 expression (P < 0.01). Additionally, the NE12.5 group had significantly higher intestinal NE lesion score, intestinal permeability, fecal E. maxima oocyst count, intestinal C. perfringens count, and jejunal IFNγ and CCL4 expression compared to the NC group (P < 0.05). In conclusion, NE negatively impacts growth performance and intestinal health in broilers, parameters regardless of the strain.

Production and purification of Clostridium perfringens type C beta-toxin and IgG and IgY antitoxins

OBJECTIVES

This study aimed to produce and purify Clostridium perfringens type C beta-toxin, sheep anti-beta toxin immunoglobulin G (IgG) and chicken immunoglobulin Y (IgY).

METHODS

Two methods were used for beta-toxin purification: single-step metal affinity chromatography (MAC) using zinc as a chelator and ion exchange chromatography (IEX). The purified and inactivated beta-toxoids were then administered to sheep and chickens in order to produce IgG and IgY.

RESULTS

All assays using the IEX failed. In contrast, MAC purified more than 21 mg of toxin per run in a single-step protocol. The purified and inactivated beta-toxoids were then administered to sheep and chickens, and IgG and IgY were purified with a high yield, medium antibody titer of 50 IU/mL, and high avidity (73.2 %).

CONCLUSIONS

C. perfringens type C beta-toxin and sheep or chicken anti-beta toxin IgG and IgY antibodies were successfully produced and purified using a simple protocol. This protocol can be used for the production of components used in the diagnosis and research of necrotic enteritis caused by C. perfringens type C, as well as for the evaluation of existing vaccines and the development of new preventive methods against this disease.

Effects of Eimeria maxima infection doses on growth performance and gut health in dual-infection model of necrotic enteritis in broiler chickens

The objective of this study was to investigate the effects of the different doses of Eimeria maxima (EM) oocysts on growth performance and intestinal health in broiler chickens challenged with a dual infection model of necrotic enteritis (NE) using EM and NetB+ Clostridium perfringens (CP). A total of 432 fourteen-d-old male Cobb 500 broiler chickens were divided into 6 groups with 6 replicates each. The six different groups were as follows: Control, non-challenged; T0+, challenged with CP at 1 × 109 colony forming unit; T5K+, T0+ + 5,000 EM oocysts; T10K+, T0+ + 10,000 EM oocysts; T20K+; T0+ + 20,000 EM oocysts; and T40K+; T0+ + 40,000 EM oocysts. The challenge groups were orally inoculated with EM strain 41A on d 14, followed by NetB+ CP strain Del-1 on 4 days post inoculation (dpi). Increasing EM oocysts decreased d 21 body weight, body weight gain, feed intake (linear and quadratic, p < 0.001), and feed efficiency (linear, p < 0.001) from 0 to 7 dpi. Increasing EM oocysts increased jejunal NE lesion score and intestinal permeability on 5, 6, and 7 dpi (linear, p < 0.05). On 7 dpi, increasing the infection doses of EM oocysts increased jejunal CP colony counts (linear, p < 0.05) and increased fecal EM oocyst output (linear and quadratic, p < 0.001). Furthermore, increasing the infection doses of EM oocysts decreased the villus height to crypt depth ratios and the goblet cell counts (linear, p < 0.05) on 6 dpi. Increasing EM oocysts downregulated the expression of MUC2, B0AT, B0,+AT, PepT1, GLUT2, AvBD3 and 9, LEAP2, and TLR4, while upregulating CLDN1, CATHL3, IL-1β, IFN-γ, TNFSF15, TNF-α, IL-10, and Gam56 and 82 on 6 dpi (linear, p < 0.05). Additionally, increasing EM oocysts decreased Pielou's evenness and Shannon's entropy (linear, p < 0.01). In conclusion, increasing the infection doses of EM significantly aggravated the severity of NE and exerted negative impact on intestinal health from 5 to 7 dpi.