PHOTO: LEX SALVERDA
or use different anticoccidials in starter, grower and finisher rations (shuttle programmes) to maintain or improve Eimeria drug sensitivity (Figure 1).
Vaccine Another strategy to improve drug sensitivity has been to switch from anticoccidial drugs to using a coccidia vaccine. Coccidia vaccines are based on specific Eimeria species and induce immunity three to four weeks after vaccination. Intro- ducing non-resistant Eimeria via vaccination can repopulate the environment to restore drug sensitivity. However, the effectiveness of this strategy to restore environmental Eimeria drug sensitivity may be impacted by litter management strat- egies (e.g. raising birds on fresh litter with each cycle or using re-used litter for several cycles). One drawback with coccidia vaccines is that they tend to impact performance during the time the birds are acquiring immunity. This associated per- formance loss is more challenging to overcome when birds are marketed at a younger age compared to those marketed at an older age because there is less time to regain that lost performance. Recovering performance loss associated with vaccination is one area in which feed additives can be used as part of a coccidiosis management strategy. Feed additives such as probiotics, prebiotics and phytogenics have become part of many coccidiosis management strate- gies because of their compliance with programmes like No Antibiotics Ever or ‘antibiotic-free’ and for their unique modes of action that complement different rotation and shuttle pro- grammes (Table 1). For example, Eimeria disrupt the intestine and nutrients leak into the lumen; live probiotics can help to overcome this by improving intestinal integrity, whereas microbial metabolic modulators can redirect the leaked nutri- ents towards beneficial microbial metabolism. If resistance is becoming a concern and an alternative is needed, using phy- togenic-saponin blends may be a way to take a break from stronger chemicals which could keep the anticoccidials more effective in the longer term. Incorporating feed additives
into rotation, shuttle or bio-shuttle programmes can help keep current anticoccidial drugs effective while maintaining performance level when other strategies are implemented.
Optimise your current rotation or shuttle programme Identifying the gap in the current rotation or shuttle pro- gramme is key to determining what strategy would best suit your needs and many different programmes can be developed depending on what is needed given your current strategy. Additionally, identifying other challenges that may be enhancing enteric challenges, such as mycotoxins or sub-optimal vitamin levels, may form part of a differential diagnosis. By filling the gap with a comprehensive solution, producers can mitigate resistance and improve coverage thus reducing the predisposing factors associated with coccidiosis and clostridial enteritis.
Figure 1 – Examples of coccidiosis control strategies Days
0
Winter Winter Spring
Summer Summer
Autumn/Fall
Coccidia vaccine
Feed additive Ionophore Chemical Coccidiostat Feed additive 7 14 21 Chemical Coccidiostat Chemical Coccidiostat
Feed additive Ionophore
Feed additive Ionophore
In poultry, there are seven
Eimeria species of the protozoal parasite coccidia that infect dif- ferent regions of the intestinal tract.
28
35
42
Straight chemical Chemical follow-through Ionophore booster Bio-shuttle Shuttle Chemical follow-through
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