Development of alternative treatment strategies for of endo- and ectoparasites of pigs and poultry
Concerns about residues of veterinary medicines and/or the increasing problem of resistance in the parasite populations has resulted in development of organic and many “low input” livestock production standards, which demand that the use of veterinary medicines should be minimised through use of alternative strategies (breed selection, management & prevention and complementary medicines). However, there are virtually no effective alternative methods for parasite control for monogastric livestock, and the use of conventional antiparasitic drugs is the rule rather then the exception in “low input” and organic farms. This situation is of particular concern in laying hen production systems in Europe, because only one anthelmintic (Flubendazole) is registered for endoparasite control in many EU countries. If widespread resistance were to develop, control of chicken helminths would be lost. Flubendazole is extensively used in organic, low input and conventional production of chickens, and can leave detectable residues in eggs. This may result in a loss of consumer confidence in organic and low input egg production. The situation in pigs is similar, although several active substances are allowed for the control of endo- and ectoparasites.
Free-range hens are also at an increased risk of being infected by Histomonas meleagridis (blackhead disease), which is transmitted by the helminth Heterakis gallinarum. At present, the use of Nifursol, the only feed additive against blackhead disease, has been banned (Council Regulation (EC) No 1756/2002 of 23 September 2002) and control of the vector helminth is therefore currently the most effective method of disease control.
It is therefore essential to develop alternative treatment strategies for endo- and ectoparasites in both pig and poultry production. The main objective should be to prevent clinical infections, because of their negative effects on animal welfare and production efficiency. Moderate subclinical infections without effects on production levels may be tolerated. Moderate challenges, which result in sub-clinical infections, may in fact be desirable in organic and “low input” systems in order to build up resistance. It may prove extremely difficult, if not impossible to eliminate sources of infection in out-door systems.
Based on the lack of alternative treatments we will evaluate further the most effective plant extract based treatments identified in pilot studies already carried out by the partners of this workpackage and a recent international workshop on “Novel Approaches in helminth control in livestock” (see section 8.4). We will carry out the following studies (sub-workpackages):
WP 4.2.1 Effect of potential new acaricides in vitro and anthelminitics in vivo. Studies will focus on evaluating compound such as extracts of Fumaria parviflora, Artemisia annua, and Azadiracha indica (Neem)
WP 4.2.2 Effect of potential alternative treatments in “on-farm” experiments. The study is based on field trials on commercial farms comparing the efficacy of novel treatments with anthelmintic based treatments and “integrated strategies” based on combined use of alternative treatments and management systems developed under WP4.1
Cost/benefit analyses on novel strategies developed under WP4.2.2 will be carried out as part of Horizontal activity 2.