A Natural Solution to Coccidiosis Control
Use of anticoccidial drugs and vaccines has long been effective in protecting in broilers, broiler-breeders and non-caged layers against Eimeria infection. But with antibiotic resistance and vaccinal reaction on the rise, many are turning to natural solutions to control coccidiosis in poultry.
28.08.2020In Brief
Vaccine- and antibiotic-based methods of controlling coccidiosis have several disadvantages.
Consumers and governments are increasingly demanding a reduction in antibiotic use in poultry.
Three natural products—phytogenic feed additives, probiotics and synbiotics—can control coccidiosis without the use of antibiotics.
Traditional Approaches to Coccidiosis Control
The traditional approach to controlling coccidiosis, using either anticoccidial drugs in broilers or vaccinating broiler-breeders and non-caged layers, has shown good protective efficacy against Eimeria infection for several decades. However, these traditional approaches have disadvantages including resistance acquisition from long-term use of single-class anticoccidial drugs and vaccinal reaction from poor vaccination practice. Moreover, rising consumer demand for antibiotic-free chicken makes traditional programs less effective as many governments classify ionophores and anti-coccidial drugs as antibiotics.
Traditional approaches to controlling coccidiosis are being replaced with natural solutions
Alternative Solutions to Controlling Coccidiosis
Given the limitations of traditional coccidiosis control programs, alternative solutions to replace or reinforce traditional programs are being sought. As Eimeria species multiply in the bird’s intestinal tract, causing tissue damage at specific lifecycle stages, any compounds which inhibit the lifecycle of Eimeria show protective efficacy against coccidiosis. Coccidiosis vaccination can confer immunity to minimize the population of Eimeria in the intestinal tract, and chemical anticoccidial drugs can inhibit a certain stage of the lifecycle in the infected enterocyte. In addition to the traditional approaches, scientific research has found that some phytochemicals can also interrupt the lifecycle of Eimeria species (Thangarasu et al., 2016).
One of the key properties of a phytogenic feed additive (PFA) is its inhibitory effect on a certain lifecycle stage of Eimeria species. Some essential oils also minimize the replication of Eimeria species by the upregulation of epithelial turnover. Induction of epithelial cell death has been characterized as a defensive mechanism used by the host to limit infection by enteric pathogens. Cell death allows the elimination of damaged cells and limits persistent pathogen colonization. The upregulation of epithelial turnover by supplementation with a PFA furthermore facilitates the repair of epithelial injuries and decreases the intestinal permeability induced by pathogens including Eimeria species.
Supplementing a diet with probiotics introduces healthy microbiota to the gastrointestinal tract
Another alternative solution to coccidiosis is the use of probiotics which introduces healthy microbiota into the gastrointestinal tract. Probiotic supplementation has been shown to improve protective efficacy against several pathogenic bacteria and parasites. Although the role of probiotics and prebiotics for the prevention of Eimeria species is not clearly determined, the immune modulation effect of a healthy microbiota, competitive exclusion to Eimeria invasion and the production of short chain fatty acids with global upregulation of enterocyte turnover all contribute to the prevention of coccidiosis.
Using Synbiotics to Reduce Coccidiosis Challenges
A 42-day trial was designed to evaluate the efficacy of a synbiotic product (PoultryStar®) to prevent the clinical signs of coccidiosis and minimize economic losses in a challenge model compared to treatment with Salinomycin. In this trial, four groups were assigned (Table 1).
Trial group | Additives | Challenge |
|---|---|---|
Negative control | - | No challenge |
Positive control | - | Challenge |
Salinomycin | 66 mg Salinomycin / kg of feed | Challenge |
Synbiotic | 1 kg of Synbiotic / kg of feed | Challenge |
On day 15, all birds except those in the negative control group were challenged with approximately 75,000, 25,000, and 75,000 counts of Eimeria acervulina, E. maxima, and E. tenella oocystes, respectively. Performance parameters including feed intake, live body weight and feed conversion ratio (FCR) were measured. On days 21 and 42, three birds from each pen were selected, euthanized and examined for the presence and degree of coccidiosis lesions. The upper, middle and cecal regions of the intestinal tract were scored, using the Johnson and Reid (1970) system, where 0 is normal and 1, 2, 3, or 4 indicate increasing severity of infection. On days 21, 28, 35 and 42, 10 fresh fecal samples were collected per pen for oocyst counting.
Performance parameters in the synbiotic group were significantly improved compared to the positive and negative control groups, but were similar to the Salinomycin group (Table 2). Cumulative oocyst shedding in the synbiotic group did not differ from the Salinomycin group (Figure 1). Intestinal lesion scores at day 21 were similar in the synbiotic and Salinomycin groups (Figure 2).
Table 2. Feed intake (kg/bird), final body weight (kg/bird) and feed conversion ratio (FCR) values on day 42
Performance parameter | Negative control | Positive control | Salinomycin | Synbiotic |
|---|---|---|---|---|
Feed intake | 4.07 ± 0.08 | 3.91 ± 0.08 | 3.93 ± 0.12 | 3.65 ± 0.05 |
Final body weight | 2.31 ± 0.08 | 1.91 ± 0.03 | 2.19 ± 0.03 | 2.01 ± 0.01 |
FCR | 1.76 ± 0.03 | 2.04 ± 0.01 | 1.79 ± 0.02 | 1.81 ± 0.02 |
Feeding a synbiotic or Salinomycin to birds gave similar effects, where birds in both groups shed less oocysts and had fewer intestinal lesions, indicative of a healthier intestine. Broilers that received the multi-species, host-specific synbiotic (PoultryStar®) in their diet performed at a similar level to broilers that received Salinomycin in terms of overall FCR, oocyst shedding, and intestinal lesions.
This article originally appeared in Asian Poultry Magazine.